The Conservation of Archaeological Materials: Current trends and future directions 9781407306575, 9781407336558

Table of contents :
Front Cover
Title Page
Copyright
Table of Contents
PREFACE
CONSERVATION: CONCEPTS AND REALITY
THE ELEMENTS OF CONSERVATION: A CONCEPTUAL MODEL
A CLEAR CASE OF PROFILING: DEFINING ARCHAEOLOGICAL CONSERVATORS IN THE U.S.
TRAINING ARCHAEOLOGICAL CONSERVATORS
RESEARCH AND TRAINING IN A FIELD CONSERVATION LABORATORY: KAMAN-KALEHÖYÜK
ARCHAEOLOGICAL CONSERVATION IN THE U.S. NAVY
GETTING THE JOB DONE: CHALLENGES PRESENTED BY CONTINUITY, CHANGE, AND CONTROVERSY IN THE CONSERVATION OF ARTIFACTS IN SHIPWRECK ARCHAEOLOGY
A WOODLAND BURIAL STUDY: DEVELOPING METHODOLOGIES FOR MONITORING AND MODELING THE BURIAL ENVIRONMENT
EXCAVATING SOIL BLOCKS AT SYLVESTER MANOR
THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE OF ARCHAEOLOGICAL FINDS
NEW PERSPECTIVES REGARDING THE STABILIZATION OF TERRESTRIAL AND MARINE ARCHAEOLOGICAL IRON
CONSERVATION OF WATERLOGGED CORK USING SUPERCRITICAL CO2 DRYING
DOCUMENTING MONGOLIA’S DEER STONES: APPLICATION OF 3D LASER SCANNING TECHNOLOGY TO ARCHAEOLOGICAL CONSERVATION
DOCUMENTATION AND LASER SCANNING OF THE CAVATES (CLIFF DWELLINGS) IN BANDELIER NATIONAL MONUMENT, NEW MEXICO
COLLABORATIVE PROGRAMS FOR USS MONITOR CONSERVATION
SAVING THE FERRYLAND CROSS: 3D SCANNING, REPLICATION, AND ANOXIC STORAGE
MIMBRES CERAMICS ANALYSIS: INTEGRATING CONSERVATION WITH ARCHAEOLOGICAL RESEARCH
NON-INVASIVE TECHNOLOGICAL STUDY OF ARCHAEOLOGICAL IRON OBJECTS
A CHANGE IN PHILOSOPHY FOR THE CARE OF ARCHAEOLOGICAL COLLECTIONS?
THE WORK OF THE ARCHAEOLOGICAL ARCHIVES FORUM IN THE UNITED KINGDOM
CREATING AND MAINTAINING A DIGITAL ARCHIVE FOR MARYLAND’S ARCHAEOLOGICAL COLLECTIONS
LOST TOWNS PROJECT ARCHAEOLOGICAL ARCHIVES: PRESERVING THE RECORDS OF A DESTRUCTIVE SCIENCE AT A SMALL INSTITUTION
A TALE OF THREE SURVEYS: CREATING A FLEXIBLE CONDITION SURVEY FOR MIXED ARCHAEOLOGICAL COLLECTIONS
REVISITING METAL ARTIFACTS FROM OLD EXCAVATIONS: STORAGE PROBLEMS AND SOLUTIONS
ASSESSMENT OF DRY STORAGE MICROENVIRONMENTS FOR ARCHAEOLOGICAL IRON
COLLABORATION AND COMMUNITY INVOLVEMENT IN ARCHAEOLOGICAL CONSERVATION
COMMUNITY INVOLVEMENT AND CONSERVATION EDUCATION
COLLABORATION FOR PRESERVATION, USE, AND KNOWLEDGE: EXAMPLES FROM THE GORDION PROJECT
HOMOL’OVI RESEARCH PROGRAM: ARCHAEOLOGY, CONSERVATION AND COMMUNITY INVOLVEMENT
ARCHAEOLOGICAL ARCHIVES – WHO CARES? THE VOLUNTEER PROGRAM AT THE LONDON ARCHAEOLOGICAL ARCHIVE AND RESEARCH CENTER, MUSEUM OF LONDON
RENOVATING THE CONSERVATION FACILITIES AT THE EGYPTIAN MUSEUM, CAIRO, EGYPT: A COLLABORATIVE EFFORT
COLLABORATION AND EDUCATION: THE EXCAVATION AND CONSERVATION OF TWO 19TH CENTURY TOMBSTONES IN WILLIAMSBURG, VIRGINIA
THE ROLE OF ARCHAEOLOGICAL CONSERVATION IN ARMED CONFLICT

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BAR S2116 2010

The Conservation of Archaeological Materials

WILLIAMS & PEACHEY (Eds)

Current trends and future directions

Edited by

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS

Emily Williams Claire Peachey

BAR International Series 2116 2010 B A R Williams and Peachey 2116 cover.indd 1

17/05/2010 12:27:37

The Conservation of Archaeological Materials Current trends and future directions

Edited by

Emily Williams Claire Peachey

BAR International Series 2116 2010

Published in 2016 by BAR Publishing, Oxford BAR International Series 2116 The Conservation of Archaeological Materials © The editors and contributors severally and the Publisher 2010 The authors' moral rights under the 1988 UK Copyright, Designs and Patents Act are hereby expressly asserted. All rights reserved. No part of this work may be copied, reproduced, stored, sold, distributed, scanned, saved in any form of digital format or transmitted in any form digitally, without the written permission of the Publisher.

ISBN 9781407306575 paperback ISBN 9781407336558 e-format DOI https://doi.org/10.30861/9781407306575 A catalogue record for this book is available from the British Library BAR Publishing is the trading name of British Archaeological Reports (Oxford) Ltd. British Archaeological Reports was first incorporated in 1974 to publish the BAR Series, International and British. In 1992 Hadrian Books Ltd became part of the BAR group. This volume was originally published by Archaeopress in conjunction with British Archaeological Reports (Oxford) Ltd / Hadrian Books Ltd, the Series principal publisher, in 2010. This present volume is published by BAR Publishing, 2016.

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BAR Publishing 122 Banbury Rd, Oxford, OX2 7BP, UK [email protected] +44 (0)1865 316916 310431 www.barpublishing.com

CONTENTS PREFACE................................................................................................................................................................ v Defining Archaeological Conservation CONSERVATION: CONCEPTS AND REALITY ................................................................................................ 1 Chris Caple THE ELEMENTS OF CONSERVATION: A CONCEPTUAL MODEL ............................................................ 11 John R. Watson A CLEAR CASE OF PROFILING: DEFINING ARCHAEOLOGICAL CONSERVATORS IN THE U.S. ........................................................................................................................................................................ 17 Claire Peachey TRAINING ARCHAEOLOGICAL CONSERVATORS ...................................................................................... 25 Virginia Greene RESEARCH AND TRAINING IN A FIELD CONSERVATION LABORATORY: KAMANKALEHÖYÜK ...................................................................................................................................................... 33 Glenn Wharton ARCHAEOLOGICAL CONSERVATION IN THE U.S. NAVY ........................................................................ 41 Claire Peachey GETTING THE JOB DONE: CHALLENGES PRESENTED BY CONTINUITY, CHANGE, AND CONTROVERSY IN THE CONSERVATION OF ARTIFACTS IN SHIPWRECK ARCHAEOLOGY ........... 47 Sarah Watkins-Kenney Fieldwork and artifact stabilization A WOODLAND BURIAL STUDY: DEVELOPING METHODOLOGIES FOR MONITORING AND MODELING THE BURIAL ENVIRONMENT .......................................................................................... 57 Karla Graham and Peter Crow EXCAVATING SOIL BLOCKS AT SYLVESTER MANOR ............................................................................. 67 Dennis Piechota THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE OF ARCHAEOLOGICAL FINDS ............................................................................................................................. 77 Sanchita Balachandran NEW PERSPECTIVES REGARDING THE STABILIZATION OF TERRESTRIAL AND MARINE ARCHAEOLOGICAL IRON ................................................................................................................................ 89 Paul Mardikian, Néstor G. González, Michael J.Drews, and Philippe de Viviés CONSERVATION OF WATERLOGGED CORK USING SUPERCRITICAL CO2 DRYING .......................... 97 Michael J. Drews, Jessica Green, Jason Hemmer, Philippe de Viviés, Néstor G. González, and Paul Mardikian Documentation and the Technical record DOCUMENTING MONGOLIA’S DEER STONES: APPLICATION OF 3D LASER SCANNING TECHNOLOGY TO ARCHAEOLOGICAL CONSERVATION ...................................................................... 103 Basiliki Vicky Karas, Harriet F. Beaubien, and William W. Fitzhugh DOCUMENTATION AND LASER SCANNING OF THE CAVATES (CLIFF DWELLINGS) IN BANDELIER NATIONAL MONUMENT, NEW MEXICO ............................................................................. 113 Jim Holmlund, Angelyn Bass Rivera, and Lauren Meyer

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COLLABORATIVE PROGRAMS FOR USS MONITOR CONSERVATION ................................................. 123 Marcie Renner and Steve Hand SAVING THE FERRYLAND CROSS: 3D SCANNING, REPLICATION, AND ANOXIC STORAGE ........................................................................................................................................................... 127 Judith A. Logan, Robert L. Barclay, Paul Bloskie, Charlotte Newton, and Lyndsie Selwyn MIMBRES CERAMICS ANALYSIS: INTEGRATING CONSERVATION WITH ARCHAEOLOGICAL RESEARCH ................................................................................................................... 135 Landis Smith NON-INVASIVE TECHNOLOGICAL STUDY OF ARCHAEOLOGICAL IRON OBJECTS........................ 143 Evelyne Godfrey Archives and Repositories A CHANGE IN PHILOSOPHY FOR THE CARE OF ARCHAEOLOGICAL COLLECTIONS? ................... 145 Hedley Swain THE WORK OF THE ARCHAEOLOGICAL ARCHIVES FORUM IN THE UNITED KINGDOM .............. 151 Kathy Perrin CREATING AND MAINTAINING A DIGITAL ARCHIVE FOR MARYLAND’S ARCHAEOLOGICAL COLLECTIONS ............................................................................................................ 155 Rebecca Morehouse, Sara Rivers-Cofield, and Julia A. King LOST TOWNS PROJECT ARCHAEOLOGICAL ARCHIVES: PRESERVING THE RECORDS OF A DESTRUCTIVE SCIENCE AT A SMALL INSTITUTION .......................................................................... 165 Caralyn Roviello Fama A TALE OF THREE SURVEYS: CREATING A FLEXIBLE CONDITION SURVEY FOR MIXED ARCHAEOLOGICAL COLLECTIONS ............................................................................................................ 169 Howard Wellman REVISITING METAL ARTIFACTS FROM OLD EXCAVATIONS: STORAGE PROBLEMS AND SOLUTIONS ....................................................................................................................................................... 181 Kathy Hall ASSESSMENT OF DRY STORAGE MICROENVIRONMENTS FOR ARCHAEOLOGICAL IRON David Thickett and Marianne Odlyha.................................................................................................................. 187 Collaboration and Community involvement COLLABORATION AND COMMUNITY INVOLVEMENT IN ARCHAEOLOGICAL CONSERVATION .............................................................................................................................................. 201 Glenn Wharton COMMUNITY INVOLVEMENT AND CONSERVATION EDUCATION..................................................... 205 Betty L. Seifert COLLABORATION FOR PRESERVATION, USE, AND KNOWLEDGE: EXAMPLES FROM THE GORDION PROJECT ......................................................................................................................................... 209 Jessica S. Johnson HOMOL’OVI RESEARCH PROGRAM: ARCHAEOLOGY, CONSERVATION AND COMMUNITY INVOLVEMENT ...................................................................................................................... 215 Teresa Moreno, E. Charles Adams, and Nancy Odegaard ARCHAEOLOGICAL ARCHIVES – WHO CARES? THE VOLUNTEER PROGRAM AT THE LONDON ARCHAEOLOGICAL ARCHIVE AND RESEARCH CENTER, MUSEUM OF LONDON ......... 219 Jannicke Langfeldt and Helen Ganiaris ii

RENOVATING THE CONSERVATION FACILITIES AT THE EGYPTIAN MUSEUM, CAIRO, EGYPT: A COLLABORATIVE EFFORT ......................................................................................................... 225 Eric Nordgren COLLABORATION AND EDUCATION: THE EXCAVATION AND CONSERVATION OF TWO 19TH-CENTURY TOMBSTONES IN WILLIAMSBURG, VIRGINIA ............................................................. 231 Emily Williams and Andrew Edwards THE ROLE OF ARCHAEOLOGICAL CONSERVATION IN ARMED CONFLICT...................................... 237 Catherine Sease

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PREFACE The genesis for this conference came from discussions held in the newly formed Archaeological Discussion group, a subgroup of the American Institute for Conservation of Historic and Artistic Works’ Objects specialty group, about the definition of an archaeological conservator and the directions in which the field was evolving. Some members wondered if the term archaeological conservation was becoming meaningless because so many archaeological objects are now encountered years after excavation and can be so divorced from any archaeological context that they are merely objects with rather larger thicker patinas. In this environment they felt that a better understanding of what set “archaeological” conservators apart from other conservators was necessary. Other members of the group argued that the conservator’s role was being challenged and defined by advances in technology. They argued that low impact, high yield, sustainable approaches remained a key aim of an archaeological conservator but that in an environment where ever more sensitive analytical techniques were being developed and used, the need for dialog in advance of action and an increasing responsibility to a diverse array of stakeholders were formative components. Other points of discussion involved: the growing understanding that the problems with curated collections, and particularly the large archives that archaeological excavation can produce, necessitated rethinking approaches to these materials; an interest in the evolution of the field outside of the US; and the increasing importance of thinking broadly in terms of site preservation and management. The conference was conceived of as a venue to discuss these areas and to engage with archaeologists and other allied professionals in a discussion about the future of the field. As the then chair of the discussion group, it was my privilege to convene the conference. However, a number of people contributed to the discussions leading up to the conference and to its planning. In particular, I would like to acknowledge the contributions of Harriet (Rae) Beaubien, Patricia Griffin, Claire Heywood, Jessica Johnson, Kirsten SuensonTaylor, Howard Wellman, Glenn Wharton and Jackie Zak. Deb Chapman masterminded the logistical arrangements for the conference. Claire Peachey’s editorial skills have been invaluable. I would also like to thank the many authors and attendees who participated and contributed and pushed the dialog forward. Emily Williams

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CONSERVATION: CONCEPTS AND REALITY Chris Caple Abstract Before any individual, organization, or discipline contemplates its future, it is prudent to know where it currently stands, where it has come from, and what the world around it is like. Thus to start a conference on ‘Current Trends and Future Directions in Archaeological Conservation’, it is surely prudent to consider, if briefly, what we understand conservation to be, i.e., the concept of conservation, and something of the history of conservation, to show how we got here. We also need to understand the reality of the world in which conservation exists, what others expect from conservation and conservators. Conservation as a cultural construct The objects and events of earlier times form our past. Lowenthal (1996), Michalski (1994), and others distinguish between two forms of past: Heritage. A personal inheritance of the past, a past which can be used in the present. It is that subsection of the past which an individual inherits: one’s family, one’s ancestry, and the traditions of one’s nation. It is exclusive, it is biased, and its purpose is to benefit the individual. It is personal memory, an attachment to people, places, and things, and a past that can be used. It is selective, the symbolic objects of a nation and the personal mementos of childhood. History. The whole of the past, raw unrefined events. History is ever-expanding and all-inclusive. It explores and explains the past, its purpose is simply to be and be known. This is the past of academic conferences and the past which fills books. It is all the objects of the past in their actual condition.

Figure 1: Mickey Mouse, a 1960s foam rubber toy, the heritage of its original child owner, but now part of the history of the era.

discipline of archaeology in the 19th and early 20th centuries that enabled us to take a detailed and logical ‘history’ approach to artifact studies. The work of PittRivers, Montelius, Petrie, and others established a series of logical processes such as stratigraphy, typology, comparative analogy, and seriation, which enables us to relate objects to activities and events in the past (Renfrew and Bahn 1991). This approach to observing the natural world and using reason to create understanding derives from the Age of Enlightenment. This same methodology drove the 17th- and 18th-century developments of science and technology, which gave rise to the Industrial Revolution and is the underlying concept of our present ‘knowledge-based society’. Modern society in both America and Europe is profoundly secular, believing that physical evidence, facts, logical deductions, science, and technology provide the answers to its questions.

History is factual, detailed, and can be dull. Heritage is personalized, simplified, and always relevant. Lowenthal (1996) illustrates heritage through the example of the Tiv, a tribe in Nigeria, who first recounted their tribal genealogy and ‘history’ to anthropologists over 50 years ago. The anthropologist’s written record no longer corresponds to the present day genealogy and ‘history’ that is recited within the tribe. As the oral genealogy and ‘history’ is their heritage, the past is serving the purposes of the present; it will be continually amended to ‘update’ it to keep it relevant and useful to the tribe of today. All aspects of our past, whether Mickey Mouse (Fig. 1) or Durham Cathedral, exist both as a detailed reality (history) and the memories, beliefs, and images (heritage) we hold in our hearts. Human beings have frequently treasured unusual objects of antiquity as mementos of their heritage. An example is the use of Roman coins as pendants in the medieval period. However, it was only the development of the

The desire in the 18th and 19th centuries to make a known, logical, organized, and coherent past led to the systematic collection, observation, and classification of 1

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS state, placing the aesthetic beauty of the object above all other things.

ancient objects. These collections of ancient objects were displayed in cabinets of curiosities and eventually gave rise to museums (Lewis 1992). These institutions can be seen to have saved objects both for historic and heritage reasons: •

To safeguard the facts and information of the past— history.

•

To safeguard the objects (physical proof) that trigger memories and responses, or that prove ‘our’ version of events, that explain, justify, and define the present, a national identity, for example—heritage.

•

Prior to the late 19th century almost all objects of the past were cleaned to make them visually appealing. Cleaning occurred to make them correspond with the aesthetic sensibility of the day. Cleaned of corrosion, devoid of paint, emasculated, these objects of the past suffered what can be described as ‘the iconoclasm of contemporary taste’, ‘restored’ to a stereotypical view of what the past should look like—i.e., ‘repristination’. This was the process of cleaning and restoring for the purposes of heritage. It supported and enhanced a personal view of the past and frequently performed the role of demonstrating the wealth and taste of the owner of the objects.

This activity of collecting and caring for objects does not occur during the initial functional or use phase of the objects, but later, when an object has become scarce and valuable. It is valuable and worthy of collection because of its age and associations. The most highly prized objects are the oldest and most culturally distinct. They are treated with reverence and receive the highest standards of museum care. This ‘care’, which involves storage, careful display, cleaning, and repair, we term conservation. There is, however, ample evidence that people of earlier ages cared for objects of beauty and antiquity in a number of ways: •

By cleaning objects, such as in the example of the ‘muntadors’, who from 1543 used coarse bread or sponges dipped in Greek wine to clean Michelangelo’s frescos on the ceiling of the Sistine Chapel (Colalucci 1991; Mancinelli 1991, 1992).

•

By reassembling broken objects, such as in the example of John Doubleday, who in 1845 worked in the British Museum adhering together the pieces of the Portland Vase (Watkins 1997; Williams 1989).

However, by the late 19th century, such cleaning and restoration activity was starting to cause concern. The idea that every building or object of the past contained valuable evidence of that past, its virtues and its values, was an idea articulated by Ruskin in 1849 in his book The Seven Lamps of Architecture. This idea was more clearly articulated in 1877 by William Morris (1996) and the members of the Society for the Protection of Ancient Buildings: ‘A church of the 11th century might be added to or altered in the 12th, 13th, 14th, 15th, 16th or even 17th or 18th centuries, but every change, whatever history it destroyed, left history in its gap and was alive with the spirit of the deeds done midst its fashioning. The result of all this was a building in which the many changes, though harsh and visible enough, were by their very contrast interesting and instructive and could by no possibility mislead.’

However, these activities were undertaken without any recording of the object or of the conservation work undertaken. Nor was there any scientific identification of the causes of decay of the object. The visual appearance of the objects was the only concern. This was noted by Nigel Williams who found that fragments of the Portland vase had been ground down in order to make them fit into the reconstruction (Smith 1992: 56).

Such views increasingly influenced society, which became concerned about the evidence that was being swept away by the extensive restoration programs. These programs were consequently curtailed. The idea that every object is, at least in part, a historic document that contains a unique record of the past, has now become widely accepted (Pearce 1994; Hodder 1994a; Hodder 1994b). As our knowledge of ancient technology has advanced and the ability of science to help us extract information has developed, objects increasingly provide a mass of detailed evidence about the past (Pollard and Heron 1996; Henderson 2000; Caple 2006).

This emphasis on the visual appearance of the object was particularly evident in these examples: •

In Britain and France in the 19th century, when ‘aesthetic restoration’ was applied, especially to churches and other buildings. Architects, such as Eugene Emmanuel Viollet-le-Duc and his colleagues, sought to strip away much of what they considered to be ‘poor quality’ later material and to restore the buildings ‘in the style of’ the Gothic period, from which many of them derived.

In the Renaissance, when nobles and princes collected objects of classical antiquity, especially marble and bronze statuary, and employed artists of the day, such as Michelangelo and Cellini, to clean and restore them (Cellini 1878; Sease 1996). This cleaning and restoration work of the Renaissance has been described as ‘repristination’ (Giusti 1994)—returning an object to its pristine, ‘as new’

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CHRIS CAPLE: CONSERVATION: CONCEPTS AND REALITY

Figure 2: Hucklesby’s Theoretical Artifact Value Curve, showing the changing value of an object over time. The object may attract care both in its initial high value phase to maintain its functionality and in its later high value phase to conserve its social meaning and ancient associations (Hucklesby 2005).

Figure 3: The stems of 17th-century wine glasses repaired with wire to restore object form, but no longer safe to use, suggesting an heirloom or representational role in this repaired, ‘conserved’ state (Willmott 2001).

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS building (Barton and Weik 1984; Peters 1981). Similarly, Aboriginal cave paintings are repainted every time a ceremony takes place (Maynard 1973).

In the 1880s a clear ethical appreciation of the importance and need for preservation of original material and of the scientific capacity to analyze and appreciate the chemical nature of decay developed. It is consequently hardly surprising that most textbooks suggest that conservation as we know it today began circa 1888 with the appointment of Friedrich Rathgen to establish a conservation laboratory at the Royal Museums in Berlin (Caple 2000: 53; Gilberg 1987). Conservation, with its requirement to record all aspects of an object and preserve it completely, deals with objects as part of the ‘history’ view of the past, rather than the ‘heritage’ view of the past.

•

In all these cases, the care and repair of the objects appears to be a form of veneration that supports the beliefs of the society that owns or controls the object. This role for artifacts in supporting the views of the society that holds or controls them is particularly emphasized when objects of one society end up in the possession of another. The objects are used not to support the original belief, but to support the beliefs of the new owning society. Thus Romans acquired the statues of Greek gods, renamed them, and gave them identities as Roman gods and heroes. Renaissance princes acquired the same Greek statues, cleaned them, and portrayed them as ideals of human form, marveling at the clean beauty of the marble and disregarding the fact that the statues were originally painted. Subsequently the Victorians acquired the statues. They continued marveling at the beauty of the sculpture form, but often modified the object by adding fig leaves and draped cloth to cover the human genitalia, which they found offensive.

Is conservation really unique to our society, or have many previous cultures appreciated the value of objects from the past and cared for ancient artifacts? Research in this area is currently being undertaken by Clare Hucklesby (Hucklesby 2005; forthcoming), who is examining earlier cultures from around the world and investigating their approaches to the care and repair of artifacts. Her work has identified two phases of repair and care of an artifact (Fig. 2): •

One which maintains the functionality of the object. This is the mending of torn clothing, patching the hole in a bucket, or rehafting an axe. It usually happens in the early initial use phase of an object’s life (Hucklesby’s AIDU, activity induced diminishment of utility, phase).

•

One of veneration which maintains the symbolic or representational nature of the object. This may take many forms, usually related to renewing the visual form of the object, such as repainting the object or blessing it and renewing its spiritual power. The object retains or enhances its meaning as a result of this process, which usually occurs later in the object’s life (Hucklesby’s RU, reinvigorated utility, phase), when it is considered valuable because of its age and associations. The objects are usually stored/located in specific ‘special’ places and treated by specific ‘special’ individuals. This appears to equate to the point in our own society when the conservation process takes place.

Our own society has collected millions of artifacts from ancient cultures and ethnically diverse societies. It places these objects in a museum, displays them for the purposes of education (one of the fundamental ideals of the Age of Enlightenment) and preserves them for future study. This represents our belief in a knowledge-based society, retaining and using physical evidence and reason to derive understanding. Throughout the 20th century we have believed that objects are historic documents that must be preserved through storage for future study and analysis. Our form of care for such objects is conservation. Thus conservation equates to the veneration activities of previous societies. From this, conservation can be understood as a social or cultural construct. It expresses the belief by modern society in the importance of knowledge and retaining information for future re-interpretation.

Her research has produced a number of examples of this veneration activity in almost all cultures. •

Roman Samian vessels held together with rivets. The vessels retain their visual form, but have greatly reduced functionality (Marsh 1981; Ward 1993; Booth et al. 2002).

•

17th-century wine glasses held together with strips of lead (Willmott 2001) (Fig. 3). No longer capable of being safely used for drinking liquids, they appear to be retained as heirlooms.

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Maori buildings and other objects repainted as a mark of respect to the spirits which inhabited the

Modern day French Catholic religious statues repainted at the request of churchgoers as part of ‘modern’ stabilizing conservation (Molina and Pincemin 1994).

Definitions and aims of conservation: RIP Having identified conservation as a social or cultural construct with beginnings in the late 19th century, one can look at its evolution since that time. From the 1930s, organizations have emerged (e.g., ICOM, IIC, AIC) to promote and develop the subject and represent its practitioners. These organizations have defined the aims or principles of conservation and the appropriate activities for its practitioners, usually as codes of ethics (AIC 1985; AIC 1994; UKIC 1983; UKIC 1996; ICOMCC 1984). The definition of conservation has

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CHRIS CAPLE: CONSERVATION: CONCEPTS AND REALITY

Figure 4: The Conservation RIP Triangle.

followed by Munoz Vinas (2005: 173–175), has defined conservation as having three competing aims:

evolved, reflecting developments in society, especially the increasing emphasis on science and technology, and more recently a greater recognition of differing approaches to objects by other cultures. Concepts such as ‘the true nature of the object’, ‘reversibility of treatments’, and ‘minimum intervention’ have all been used in the definition of conservation, and then as conservation and society developed, were subsequently considered insufficiently accurate or in need of further qualification. Definitions of conservation are often highly aspirational, fact- or goal-based (Munoz Vinas 2005: 18), and in seeking to define what conservation is in a single phrase or statement, have perhaps failed to focus on the competing nature of the requirements of conservation and the ‘area’ in which professional conservators make judgments. Caple (2000: 33–35),

Revelation: Cleaning and exposing the object, to reveal its original form as it was at some point in its past. The visual form can be restored to give the observer, typically a museum visitor, a clear visual impression of the original form of the object. Investigation: All the forms of analysis used to uncover information about the object, from visual observation and X-radiography to complete destructive analysis. Preservation: The act of seeking to maintain the object in its present physical and chemical form, without any further deterioration. This typically involves a full range of preventive conservation practices and the stabilization processes of interventive conservation. 5

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS up for investigation is conservation. Only when there has been consideration and action to provide a balance of revelatory, preservative, and investigative processes can it be claimed that conservation is being undertaken. If an unequal balance of resources is revealed, this must be justified—this requirement enables a wide range of arguments to be made, entertained, and, if appropriate, acted upon.

The balance of these three aims forms a triangle that defines the area in which activities can be described as conservation, and in which professional conservators work. Every conservation activity has aspects of these three aims and can be plotted within this triangle; see Figure 4. Cleaning an object may aid its preservation, reveal the form of the object, and uncover information about it. Activities such as recording, though dependent upon investigation and used for education and thus revelation, are intended primarily as a means of preservation. The concept of a space, the RIP triangle, in which conservators make balanced judgments, has been particularly useful in enabling conservation students to explore the competing requirements of conservation.

The role of the object as a historic document requires that it is preserved for the future, and/or it is investigated and information obtained. The role of the object as part of our heritage is to reveal/provide, to a wide audience, a visual symbol of the past, a piece of physical evidence that supports our stories and ideas about the past. Thus the RIP triangle inherently recognizes both the history and heritage roles that objects are asked to perform.

There are a number of benefits and some limitations in using the RIP triangle to define/describe conservation: •

It is a relative measure with no numerical scales or absolute values. The relative ratios of the different processes may allow the suggestion that the balance differs for different types of object. Archaeological objects usually have higher ratios of investigation and preservation than revelation, whereas an object with considerable intrinsic aesthetic properties such as a work of art may have a higher ratio of revelation to preservation or investigation.

•

It encourages conservators to stand back from the conservation process, to be more conscious of the balance/compromise they make in undertaking their selected conservation treatment.

•

It emphasizes that the aims of both cleaning and restoration are to reveal the form/appearance of an object at an earlier point in its life. It is, however, only when balanced with preserving all the original material of the object and investigating the nature of the object that cleaning or restoring an object could be described as conservation.

Education Although we may have a clear concept about conservation, the problem regarding a conceptual understanding about the nature of artifacts is much larger and draws in many other professions. It is important that conservators understand how their archaeological, anthropological, and curatorial colleagues are using objects and can contribute to their developing ‘narratives’ of the past. Separate training courses, separate literatures, and the use of different words is creating an increasing distance between conservators, archaeologists, and curators. This leads to entrenched positions and stereotypical depictions: ‘The former, often curators, consider that the latter, often conservators, tend towards the same kind of inconvenient zealotry as Fire Prevention Officers, and lack understanding of the underlying issues, while the latter accuse the former of recklessness and lack of professionalism.’ (Apollo 1987) Theoretical approaches in archaeology, anthropology and curatorship have followed post-modern philosophy in terms of the relative nature of objects, considering them primarily as cultural signifiers (Pearce 1994; Dobres 2000). Conservation continues to study objects as physical entities focusing on accurate materials identification and the technology of fabrication. This divergence also exists within the discipline of archaeology. Increasing distance between the factual skilling required by field archaeology and the academic research tradition of universities is becoming evident in the UK. Modern archaeology students are better able to discuss issues such as gender and cultural identity in prehistory than they are able to identify and date ceramic shards.

‘Regardless of whether adding (restoring) or subtracting (cleaning) material, the object moves from a form created by the indiscriminate hand of fate to a truer form, one which the conservator can justify as (more) important and informative to the viewer.’ (Caple 2000: 35) •

•

It is independent of resources. Thus, even if you are simply repackaging objects in a store as a preservative action, the conscious act of ensuring the objects and boxes are correctly labeled relates the object to its museum record and all its accumulated information, and ensures ready access for investigation and display purposes. Thus you need not be a qualified conservator to engage with the aims and aspirations of conservation.

The need to maintain and enhance communication is paramount. It is essential that we learn to place value on the information that can be provided by colleagues and avoid the stereotypical accusations of academic fashion or commercial necessity. A common educational foundation for object study would undoubtedly help.

The RIP triangle does not provide ‘carte blanche’ to claim that displaying actively degrading objects, reburying objects to preserve them, or cutting them 6

CHRIS CAPLE: CONSERVATION: CONCEPTS AND REALITY and use, such as object biographies (Appadurai 1986; Miller et al. 1991; Kingery 1993), châine opératoir (Chilton 1999), flow models for the life cycle of durable elements (Ross 1991: 250; Schiffer 1972: 158), Object Production and Use Sequences (Caple 2006) and similar models (Tite 2001: 444; Kingery 1996: 176). Such models provide a method of enabling the details about an individual object to feed into larger cultural historical narratives and thus are a potential tool for communication between conservators, curators, archaeologists, and anthropologists. To achieve such an aim, such models must be widely taught and used.

Perhaps the simplest common framework for all groups is to consider objects as instruments (functional), symbols (meaning), and documents (history). •

Object as instruments (Functional, Utilitarian) Objects have an initial value because they perform a function for the society or the individuals within it. Thus a hammer hammers and a saw saws. Maquet (1993) suggests that an object’s role as an instrument can be inferred from its design and the materials from which it is formed. As such, it is independent of its cultural determination.

The reality Modern society places a number of pressures on archaeologists, curators, and managers:

‘The meaning of an object, what it stands for, is cultural when it is recognized as part of a collective reality built by a group of people. But in most cases it is not culture specific: it is grounded in common human experiences.’ (Maquet 1993: 31) •

Objects as symbols (Signs, Aesthetic Entities) Depending on the differing experiences of the viewers, the symbol can mean different things to different viewers. A hammer may be an essential tool to a blacksmith, or it can be seen as a symbol of oppression or a weapon of war. The context in which an object appears invariably helps define its meaning. Since most symbols are designed to signify to members of the same culture and since the members of a culture, will share many experiences and ideas in common, members of that society can normally ‘read’ the symbol, within its context, correctly.

•

‘Quick Fix’ solutions. Because modern technology has solved many problems in science, medicine, and engineering, it is imagined that there are ‘quick fix’ solutions to conserving degrading artifacts. Unfortunately, this is rarely the case. The problems are considerable and the funding and research have not yet been made available to understand and solve them. A number of ‘quick fix’ science solutions of the past, such as shellac and soluble nylon, have proved to be disastrous, creating much larger longterm problems. This has made conservators wary of any new ‘quick fix’ solution, though such attitudes are frustrating to scientists developing new conservation methods and materials.

•

Short-termism. Many archaeological artifacts need a lifetime of care, but resources are often limited to the short period around the excavation. Many archaeologists’ primary interest in their finds is in the period until their excavation is published. Too frequently the concern is for the next 2 or 3 years, not for the next 50 or 100. Governments and funding bodies often take a short-term view. The curator and the conservator are often the only individuals working with a view to the longer term.

•

Unreasonably high expectations. Owners, curators, and archaeologists have seen pictures of beautiful, cleaned and restored objects, and imagine that their object can and should look just as good. Their expectations have been raised. They are frequently unaware that such well-preserved examples are the exception, not the rule, and that considerable resources are often required to achieve a highly cleaned and restored state. The question of whether it is appropriate to so completely clean and restore an object is often unwelcome.

•

Resource shortage. Since archaeological finds reveal knowledge that does not have a commercial value, funding for conservation is at charitable/recreational/educational levels. Such funding is frequently limited; however, the expectation about the quality and quantity of

‘Artifacts serve both utilitarian and social/ideological functions; they are both tools and signs. This is the underlying reason for the vision of some historians that all objects, no matter how utilitarian and functional must be considered art. All are signs.’ (Kingery 1996: 197) Examples of the symbolic nature of objects include their association with spirits (i.e., spirit containers) or with differential socially ascribed value such as coinage or the objects of the kula ring (Appadurai 1986: 18). •

Objects as historic documents Every object documents its past; it is simply a question of developing the skills and analytical techniques to read this document. An object contains information about the materials from which it was made, the way in which it was assembled, and every incident that occurred in its life. In reality we do not yet have the technology to ‘read’ all of this information, such as the fingerprints and DNA of everyone who has handled the object, and much information is lost, obscured by later activities.

It is clearly desirable to discuss and utilize more complex models of the processes involved in object manufacture 7

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS don’t think that is really necessary’ attitudes develop. Such attitudes encourage archaeologists, metal detectorists, divers, owners, and enthusiasts to ‘try their hands’ at conservation. Although they frequently suggest that they are trying to ‘save’ the object, there are few that rebury objects or store them away from view in controlled conditions for decades. In reality what many enthusiasts want to see is a ‘nice’ looking object, something which corresponds to their idea of what such an object of the past should look like.

information that can be provided, especially through science and technology (e.g., high-resolution CAT scans), is always increasing. The ability to retrieve more information means that archaeologists save more artifacts than they used to—we can now get information out of the scraps that used to be thrown away. Consequently, conservators are always being asked to do more with less. •

•

Standards. To keep down costs, competition between suppliers of goods and services is encouraged throughout much of the world. Just as it could be suggested that conservation could be done more cheaply by an archaeologist who has read a book about conservation, so archaeology could be done, at a far lower price, by a construction worker who has read a book about archaeology. Both archaeology and conservation could potentially pass to the cheaper, unqualified, and incompetent practitioner. The only way to stop this potential damage and loss of information is to set and maintain standards enforced through legislation. This is expensive and we face eternal problems of what are the appropriate standards and who should set them.

This is what the Renaissance princes wanted who employed Benvenuto Cellini to chisel the corrosion off of bronze statues. It is also what Viollet-le-Duc and the Victorian restoration architects wanted. They knew what the past looked like, they wanted to see it in physical form. This is repristination, not conservation. This sees the present as important, rather than the future. It uses objects only as heritage, not as history. Heritage is a very real and powerful cultural force. It can be caricatured as the myths and legends of the past, rather than the reality. It is, however, a reasonable question to ask, ‘Does society need the myths and legends more than it needs real history?’ Powerful societies have been created on myths and legends. If military and economic strength is seen as of paramount importance in a society, maybe myths and legends are more useful than truth. Perhaps what every government wants is heritage, what archaeologists and conservators are providing is history.

Financial/Cultural object value. Where the object is a high-value item, either in cultural or financial terms, the cost of conservation is seen as small, and thus conservation resources can be lavished on oil paintings and rare and ancient archaeological artifacts. Objects considered recent and numerous, as many historic, folk art, and archaeological objects from the last 300 years are, are seen as lower value and it is more difficult to obtain funding for conservation for such everyday artifacts.

Bibliography AIC (American Institute for Conservation). 1985. Code of Ethics and Standards of Practice. New York: AIC. AIC (American Institute for Conservation). 1994. Code of ethics and guidelines for practice. AIC News, May 1994: 17-20.

One approach to these problems is to recognize that we do not have the resources to conserve all the objects of the past. So we must make some choices. As our museum collections grow, we should perhaps no longer consider objects as individual items but as collections. If we consider the RIP triangle with a collection of objects, some could be preserved, some investigated (destructively if needs be), and some revealed (cleaned and restored) for display. This is conceivable with, for example, collections of identical mass-produced objects of the 19th and 20th centuries. It allows a wider variety of conservation approaches and helps to justify some measures, such as preservation in situ and reburial, since there are other object examples that remain revealed on display.

Apollo 1987. Editorial: Mass conservators. Apollo 126: 390-391.

tourism

and

the

Appadurai, A. 1986. Introduction: Commodities and the politics of value. In The Social Life of Things, ed. A. Appadurai. Cambridge: Cambridge University Press. Barton, G., and S. Weik. 1984. Maori carvings: ethical considerations in their conservation. In ICOM-CC 7th Triennial Meeting, Copenhagen 1984. Copenhagen: ICOM-CC. Booth, P., J. Evans, and J. Hiller. 2002. Excavations in the Extramural Settlement of Roman Alchester, Oxfordshire 1991. Oxford: Oxford Archaeological Unit.

The disparity between high expectations and the reality of increasing numbers of objects and limited resources leads to frustrations by archaeologists, amateur enthusiasts, object owners, metal detectorists, sports divers, public and private heritage funding agencies, as well as by conservators. The high costs of conservation, especially for steps such as recording, scientific investigation, and long-term preservation, can be seen by some as unnecessary. ‘Why should I pay for that?’ or ‘I

Caple, C. 2000. Conservation Skills: Judgement, Method and Decision Making. London: Routledge. Caple, C. 2006. Objects: Reluctant Witnesses to the Past. London: Routledge.

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CHRIS CAPLE: CONSERVATION: CONCEPTS AND REALITY Cellini, B. 1878. Memoirs of Benvenuto Cellini, a Florentine Artist. Trans. T. Roscoe. London: G. Bell.

Lowenthal, D. 1996. Possessed by the Past. New York: The Free Press.

Chilton, E. 1999. Material Meanings: Critical Approaches to the Interpretation of Material Culture. Salt Lake City: University of Utah Press.

Mancinelli, F. 1991. The frescoes of Michelangelo on the vault of the Sistine Chapel: conservation methodology, problems and results. In The Conservation of Wall Paintings, ed. S. Cather. Los Angeles: Getty Conservation Institute.

Colalucci, G. 1991. The frescoes of Michelangelo on the vault of the Sistine Chapel: original technique and conservation. In The Conservation of Wall Paintings, ed. S. Cather. Los Angeles: Getty Conservation Institute.

Mancinelli, F. 1992. Michelangelo’s frescoes in the Sistine Chapel. In The Art of the Conservator, ed. A. Oddy. London: British Museum.

Dobres, M. 2000. Technology and Social Agency. Oxford: Blackwell.

Maquet, J. 1993. Objects as instruments, objects as signs. In History from Things, eds. S. Lumber and W.D. Kingery. Washington, DC: Smithsonian Institution Press.

Gilberg, M. 1987. Friedrich Rathgen: the father of modern archaeological conservation. Journal of the American Institute for Conservation 26 (2): 105-120.

Marsh, G. 1981. London’s Samian supply and its relationship to the development of the Gallic Samian industry. In Roman Pottery Research in Britain and North West Europe. BAR (International Series) 123i, eds. A. Anderson and A. Anderson. Oxford: British Archaeological Reports.

Giusti, A. 1994. Filling lacunae in Florentine mosaic and tessera mosaic: reflections and proposals. In Restoration: Is It Acceptable? British Museum Occasional Paper No. 99, ed. A. Oddy. London: British Museum.

Maynard, L. 1973. Restoration of Aboriginal rock art – the moral problem. In Proceedings of the National Seminar on the Conservation of Cultural Materials, Perth 1973, eds. C. Pearson and G.L. Pretty. Perth: Institute for the Conservation of Cultural Material.

Henderson, J. 2000. The Science and Archaeology of Materials. London: Routledge. Hodder, I. 1994a. The interpretation of documents and material culture. In Handbook of Qualitative Research, eds. N.K. Denzin and Y.S. Lincoln, 393-402. London: Sage.

Michalski, S. 1994. Sharing responsibility for conservation decisions. In Durability and Change, eds. W.E. Krumbein, P. Brimblecombe, D.E. Cosgrove, and S. Staniforth. Chichester, UK: Wiley.

Hodder, I. 1994b. Theoretical archaeology: a reactionist view. In Interpreting Objects and Collections, ed. S. Pearce, 48-52. London: Routledge.

Miller, G.L., O. Jones, L. Ross, and T. Majewski. 1991. Approaches to Material Culture Research for Historical Archaeologists. California, PA: The Society for Historical Archaeology.

Hucklesby, C. 2005. Changing values: exploring the aetiology behind the nature of conservation among different cultural groups. In ICOM-CC 14th Triennial Meeting, The Hague 2005. The Hague: ICOM-CC.

Molina, T., and M. Pincemin. 1994. Restoration acceptable to whom? In Restoration: Is It Acceptable? British Museum Occasional Paper No. 99, ed. A. Oddy. London: British Museum.

Hucklesby, C.L. Forthcoming. An Anthropology of Conservation. PhD thesis, University of Durham, UK. ICOM-CC (International Council of Museums Conservation Committee). 1984. The ConservatorRestorer: A definition of the profession. Copenhagen: ICOM-CC.

Morris, W. 1996. Manifesto of the Society for the Protection of Ancient Buildings. In Historical and Philosophical Issues in the Conservation of Cultural Heritage, eds. N. Stanley Price, M. Kirby Talley Jr., and A.M. Vaccaro. Los Angeles: The Getty Conservation Institute.

Kingery, W.D. 1993. Technological systems and some implications with regard to continuity and change. In History from Things, eds. S. Lumber and W.D. Kingery. Washington, DC: Smithsonian Institution Press.

Munoz Vinas, S. 2005. Contemporary Theory of Conservation. Oxford: Elsevier Butterworth Heinemann.

Kingery, W.D. 1996. Materials science and material culture. In Learning from Things, ed. W.D. Kingery. Washington, DC: Smithsonian Institution Press.

Oddy, W.A. 1996. The Forbes Prize Lecture 1996. IIC Bulletin No. 5, October 1996: 1-5.

Lewis, G. 1992. Museums and their precursors: a brief world survey. In Manual of Curatorship, ed. M.A. Thompson. London: Butterworth Heinemann.

Pearce, S.M. 1994. Thinking about things. In Interpreting Objects and Collections, ed. S. Pearce, 125132. London: Routledge.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Peters, K.M. 1981. The conservation of a living artifact. A Maori meeting house at Makahae. A preliminary report. In ICOM-CC 6th Triennial Meeting, Ottawa 1981. Ottawa: ICOM-CC.

Biography Chris Caple graduated from University of Wales, College of Cardiff in 1979 with a BSc in archaeological conservation. He carried out his doctoral research at the University of Bradford. In 1988 he became lecturer in archaeological conservation and archaeological science at the Dept. of Archaeology, University of Durham, becoming a senior lecturer in 1996. Between 1984 and 1995 he was director, for Cadw, of the archaeological excavations at Dryslwyn Castle in Dyfed. He is author of Conservation Skills: Judgement, Method and Decision Making (2000), and Objects: Reluctant Witnesses to the Past (2006). He is an Accredited Conservator Restorer (ACR), Fellow of the International Institute for Conservation (FIIC), and Fellow of the Society of Antiquaries (FSA).

Pollard, M., and C. Heron. 1996. Archaeological Chemistry. Cambridge: Royal Society of Chemistry. Renfrew, C., and P. Bahn. 1991. Archaeology: Theories, Methods and Practice. London: Thames & Hudson. Ross, L.A. 1991. 16th century Spanish Basque coopering. In Approaches to Material Culture Research for Historical Archaeologists, eds. G.L. Miller, O.R. Jones, L.A. Ross, and T. Majewski. California, PA: The Society for Historical Archaeology. Schiffer, M.B. 1972. Archaeological context and systemic context. American Antiquity 37: 156-165.

Address Department of Archaeology Durham University South Road Durham, DH1 3LE UK

Sease, C. 1996. A short history of archaeological conservation. In Archaeological Conservation and its Consequences, Preprints of the Contributions to the Copenhagen Congress, 26–30 August 1996, eds. A Roy and P. Smith, 157-161. London: International Institute for Conservation. Smith, S. 1992. The Portland vase. In The Art of the Conservator, ed. A. Oddy. London: British Museum Press. Tite, M.S. 2001. Materials study in archaeology. In Handbook of Archaeological Sciences, eds. D.R. Brothwell and A.M. Pollard. London: Wiley. UKIC (United Kingdom Institute for Conservation). 1983. Guidance for Conservation Practice. London: UKIC. UKIC (United Kingdom Institute for Conservation) 1996. UKIC Code of Ethics and Rules of Practice. London: UKIC. Ward, M. 1993. A summary of the Samian Ware from excavations at Piercebridge. Journal of Roman Pottery Studies 6: 15-22. Watkins, S.C. 1997. Science and conservation at the British Museum: a nineteenth century legacy. In The Interface between Science and Conservation. British Museum Occasional Paper No. 116, ed. S. Bradley. London: British Museum Press. Williams, N. 1989. The Breaking and Remaking of the Portland Vase. London: British Museum Publications. Willmott, H. 2001. A group of 17th century glass goblets with restored stems: considering the archaeology of repair. Post Medieval Archaeology 35: 96-105.

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THE ELEMENTS OF CONSERVATION: A CONCEPTUAL MODEL John R. Watson Abstract Marie Berducou has distilled the objectives of conservation into three: accessibility, durability, and integrity. Considered with the usual actions of conservation—investigation, intervention, and prevention—a matrix of objectives and actions emerges, constituting a conceptual model. Like the periodic chart of the elements, the model shows relationships among the component parts of the conservation discipline. The model can identify blind spots and imbalances. Built into the matrix are tensions that derive from the paradox of restoration and the overlap of interests between conservators and archaeologists. The matrix also accommodates the diverse values of conservators and other stakeholders, particularly in the dichotomy between the economic and informational value of objects. The model thus sheds light on the meaning and role of conservation and on several of the controversies in which we sometimes find ourselves. The model also carries implications, for example, about the potential for archaeological conservators as collaborators with archaeologists.

The first objective to define is Accessibility. Although bound in the present, we have an impulse to pursue the past by connecting with the arts and artifacts of our ancestors, and by following their footprints through time. Through the material legacy of the past, we gain Access to their world. The problem, of course, and what gives rise to the profession of conservation, is that objects from the past are obscured by time, and have often lost some of the qualities that made them useful, beautiful, or otherwise desirable and meaningful in their own period. Such losses now stand in the way of our access to that world. When a paint loss on a portrait takes all attention away from the intended subject of the painting, the museum visitor sees not a person, or even a work of art, but a scar. Accessibility is similarly reduced when archaeological fragments are masked by corrosion and concretions, or are so unstable that they crumble in the examiner’s hands. Many actions of conservators help make the objects more readable and the past more accessible, not just for the museum-going public, but also for those of us who are specialists and researchers.

The ‘land of conservation’ If we were to draw a map of the ‘land of conservation’, what would it look like? Is it vast with many different regions? Is there a vibrant intellectual exchange with other nations? Are its borders defined by broadly accepted treaties, and is this nation at peace with its neighbors? Is it unified around a clear constitution, or is it divided into separate tribes? Is it a hierarchical place, built on the side of a mountain, with an ivory tower reaching heavenward? Is it an island, far detached from other nations? Does it always appear on everyone else’s world map?

The second objective of conservation is Durability, and it has to do with the stewardship imperative of conservation. So important is this obligation to the future, that the opening paragraph of the preamble to the American Institute for Conservation’s Code of Ethics, puts it above all else: ‘The primary goal of conservation professionals…is the preservation of cultural property…for future generations’ (italics added). Not only do we want to extract from objects information for our own access to the past, but we accept the obligation to accomplish this in a way that preserves that evidence for future re-evaluation and re-interpretation.

Maps give us a sense of our context within the greater world. They show us where we are, where we’ve been, and where we need to go. Most importantly, maps help us to see the big picture. They are tools to help us to see our blind spots, and to plot course corrections.

It is this idea that objects contain physical evidence that brings us to the third objective of conservation, Integrity, for what good is evidence that has been much tampered with? To have integrity, historic artifacts must actually and materially be from their historical period. The physical evidence that purports to be from the past must not be falsified by our restorative alterations, nor should it be made counterfeit. When there is interpretation and conjecture in our treatments, and it can be argued that all treatment is in some way interpretive, the integrity of the object—the veracity of its historical testimony—is protected only to the extent that we make clear what we have done, so future investigators can extrapolate the pre-treatment state. Our aspirations for minimal and targeted intervention, ‘reversibility’, and certainly treatment documentation, all spring forth from the integrity objective.

Our proposed ‘map’ is the chart in Fig. 1. The lines of longitude and latitude lay out a matrix in which we have identified the elements of conservation. The objectives of conservation are in the horizontal bands, and the daily activities of conservation in the vertical bands. Each of the things we do as part of our work in conservation can thus be placed according to the objective it serves. The elements of conservation: objectives Marie Berducou proposes a distillation of conservation objectives as they relate to our work with objects: their accessibility, their durability, and their integrity (Berducou 1996). Before we add a fourth objective, these three most basic objectives deserve some definition.

These are high-minded objectives indeed, and given full rein, they might make our jobs almost impossible, put our costs out of reach, or cause us to forget the

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS

Figure 1: The elements of conservation: a conceptual model.

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JOHN R. WATSON: THE ELEMENTS OF CONSERVATION: A CONCEPTUAL MODEL

understandable? Of the whole ‘land of conservation’, this is the province with the oldest history. This is where the early ancestors of modern-day conservators came from: the province of restoration. There is some baggage here that has made it difficult for some conservators to admit restoration as being part of our work. After all, we are beyond those dark days; ‘we do not do restoration’, they would say, ‘but occasionally aesthetic reintegration’. As the still-young profession matures, however, the time for simple-minded distancing from traditional restoration has surely passed, and we are ready to reclaim and redefine restoration in the form it now takes, tempered by the Integrity objective. Although we approach restoration very differently today, and other goals are balanced in our approach, we do occasionally intervene with objects to restore at least some of their characteristics to a past state. Restorative conservation plays a bigger part in the work of some conservation specialties than others, but even archaeological conservators may find themselves shaping a flattened leather shoe, removing deposits to reveal decorative detail, or fitting back together the fragments of a pot, and adding fills. Those are all forms of restoration, and they are Interventions in service to Accessibility.

gritty realities of the real world. Thus we have added a fourth objective, Practicality. This is a necessary part of the system if conservation is to be sustainable, acceptable, or even possible. Practicality reminds us that in everything we do, we have to be intelligent about balancing limited time, money, and human resources. The elements of conservation: actions The vertical bands of longitude are where we shall place the actions of conservation, broken down once again into four, namely Investigation, Intervention, Prevention, and Communication. Investigation involves many types of examination, scientific and sometimes instrumental analysis, and research into the properties of artifact and conservation materials. To avoid confusion with Chris Caple’s RIP Balance (revelation, investigation, preservation), also described in this volume, note the way our model differs in considering Investigation as an action that can serve the Accessibility (or ‘revelation’) objective. When an object undergoes some sort of destructive analysis, for example, it is investigation to reveal information about the past. Thus, destructive analysis is the action of Investigation serving the objective of Accessibility (or ‘revelation’). Conservators also investigate modern materials that might be used as consolidants to ensure they are stable. That would be Investigation in service to the objective of Durability.

Balancing conflicting objectives The Elements of Conservation model illustrates the breadth of the conservation discipline, and the diversity of its activities. The Intervention column, for example, shows a contrast between the objectives of Accessibility and Integrity. Archaeology professionals know better than most in the museum world that the conflict between these goals presents a paradox. Alteration to an artifact by cleaning, stabilization, or restoration serves the Accessibility and Durability objectives, but like the excavation itself, inescapably disturbs and destroys evidence to some degree, putting those actions in tension with the Integrity objective. Burial dirt on an archaeological fragment obscures the object and begs one kind of treatment, while the information about the burial context in that same dirt demands less cleaning or no cleaning at all. It is a paradox faced by all conservators, and it is the reason our work involves critical thinking and constant judgment.

The second class of actions is Intervention, which entails all treatment, including stabilization or restoration, as in the case of putting ceramic shards back together. Prevention activities include providing safe handling, exhibition, and environments for objects on exhibit or in repositories. Finally, Communication gets its own column: each objective requires a great deal of negotiating with the other stakeholders, and reporting for the benefit of future generations, who are among the most important stakeholders. Intersections of longitude and latitude The boxes on the map, formed by the intersections of objectives and actions, contain the daily tasks of conservation. In the first box, for example, we include the types of Investigation that serve the Accessibility objective. What kind of investigations take place at the hands of conservators that help paint a picture of the past? This could include anything that reveals information from and about the object and its context. We might make a radiograph of a lock mechanism encased in a mass of corrosion to reveal its period, based on its shape and construction. Other clues might emerge, as when the lock appears to have been intentionally broken. A conservator helps to gain access to the past by using scientific methods for characterizing an object’s materials, or by chemically identifying the corrosion to reveal more about the burial context. All of this is Investigation in service to Accessibility.

Of course, some people may not care very much about the context, while others may feel quite devoted to preserving such evidence. The compelling pros and cons of taking cleaning or restoration to one level or another set up conflicts within most of us, and often between groups of people in the broader archaeology discipline. Polarization and a breakdown in collaborative relationships can result. What this overall map is showing us, however, is that unlike traditional restorers with their relative disinterest in preserving material evidence, conservators embrace both halves of this dichotomy. Their objectives cover Accessibility as well as Integrity.

This next box is Intervention in service to Accessibility. What do conservators do to reverse the effects of deterioration in order to make objects more

Our predecessors from the field of traditional restoration also differ from today’s conservators in that conservation 13

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS relies more heavily on science and technology. Although science is not an objective per se and does not head one of our action categories, science and technology potentially figure into most of the sections of our map.1 The Prevention column, for example, occupies a significant swath on the conservation map, and highlights the major role played by science in controlling the chemical and micromechanical processes of aging. Conservators have the specialized expertise to measure and control those processes, giving conservators an important place in the designing and maintenance of collection repositories.

archaeologist and continues through the immediate stages of object processing. Conservation care thus begins not with the conservator, but with the archaeologist. Just as the borders between nations and states are invisible but real, however, so is the point in the conservation of archaeological objects that marks the beginning of specialized conservation. The world of medicine offers a useful example. Some medications, though inevitably abused by some, are nevertheless sufficiently standardized, predictable, and broad in their effectiveness, that they can be purchased and used without the direct supervision of a medical doctor. Labeling gives detailed instructions for their use, and users are instructed to consult a doctor should certain side affects appear. These are called ‘over-the-counter’ medications. Not all healthcare can be accomplished using this one-size-fits-all approach. ‘Prescription’ medications cover other medical needs, and are available only with a doctor’s direct involvement. The choice and application of these medications need the judgment of a specialist who understands on a technical and scientific level the interactions between the drug and the specific patient. These drug therapies may be more situationspecific, require careful adjustment during their course, or have greater consequences if something goes wrong.

Cross-border collaboration: conservators and archaeologists The metaphor of this chart being a map raises the interesting issue of borders. How permeable are the boundaries surrounding archaeological conservation? How exclusive or inclusive is this society? What, for example, should be the division of labor between conservators and archaeologists? In terms of this map of the Elements of Conservation, there appears to be a high degree of overlap between conservators and archaeologists, especially in the topmost objective. Archeologists and conservators share the work of facilitating access to the past in various ways. What keeps the peace at this border, however, is that their respective actions in service to Accessibility are somewhat different and complementary. One could say they share the same latitude, but occupy different longitude (including some actions that do not appear on the conservation map), so the potential for collaboration is key. We gain better access to the past when the archaeologist contributes intelligence about cultural context (among other things), while the conservator undertakes treatment designed to reveal evidence and contributes technical investigations of physical evidence. The division of labor can also be understood in terms of differences of emphasis in values. The conservation discipline is oriented more to the informational value of objects than to associative/symbolic value, aesthetic value, or economic value.2 The collaborative dialog between conservators and archaeologists depends both on this division of labor, and equally on the two specialists being reasonably conversant in the other’s area of expertise. This last point requires some mutual trust, as collaboration of this kind is not possible when either party is overly concerned about protecting professional turf.

Similarly, some conservation treatments can be carried out by archaeologists according to broadly applicable procedures devised by conservators and conservation scientists, while others require situation-specific treatments designed and supervised by conservation professionals. Unlike its counterpart in the medical realm, the line between ‘over-the-counter’ and ‘prescription’ is less formalized in the care of historic artifacts. The implications are that some conservation can and should be undertaken by archaeologists, and that conservators have important expertise to offer at every stage from excavation to the planning and maintenance of collection repositories. A useful framework The Elements of Conservation is a conceptual model with implications and uses beyond what has been summarized here. Individual conservators can highlight their strengths wherever they are represented on the model, thereby identifying the areas in which they still need training or experience. Differences in the areas of expertise between conservators indicate where there is the greatest need for collaboration. Training programs can take such a framework into account in evaluating their curriculum. Archaeologists can see where the conservation discipline differs from their own, thereby discerning the role of conservation professionals in the investigation, treatment, and long-term preservation of objects.

There is also an overlap between conservators and archaeologists in the area of Intervention, which begins, after all, at the moment of excavation by the 1 Miriam Clavir (2002, p.4) cites science and integrity as the two dominant and distinguishing values in conservation, accusing the profession of failing to balance these with other worthy considerations. Our conceptual model is consistent with her view, and articulates the importance of the Accessibility objective to be part of the conservator’s world view. 2 For the taxonomy of values from which these four are drawn, see Lipe, 1984.

The model shows the breadth of our profession in its objectives and activities. Pursuing any one of these actions in isolation cannot qualify as good conservation just because the action lies within the borders of the map. One must first consider the costs and benefits of the 14

JOHN R. WATSON: THE ELEMENTS OF CONSERVATION: A CONCEPTUAL MODEL available alternatives in terms of all the objectives. It is here that the Practicality objective takes on additional importance. We must accommodate the limitations of time and money, but must do so with balanced consideration of the other objectives, as well. When practicality dominates the other objectives, it can seduce us to continuously lower our standards for reasons of convenience. The model encourages professional rigor, as each of the objectives of conservation place conditions on the other three. Bibliography Berducou, M. 1996. Introduction to archaeological conservation. In Historical and Philosophical Issues in the Conservation of Cultural Heritage, eds. N.S. Price, M.K. Talley Jr., and A.M. Vaccaro, 248-259. Los Angeles: The Getty Conservation Institute. Clavir, M. 2002. Preserving What Is Valued: Museums, Conservation, and First Nations. Vancouver and Toronto: UBC Press. Lipe, W. 1984. Value and meaning in cultural resources. In Approaches to the Archaeological Heritage: A Comparative Study of World Cultural Resource Management System, ed. H. Cleere. Cambridge: Cambridge University Press. Biography John Watson is conservator of instruments and mechanical arts at the Colonial Williamsburg Foundation. His work in recent years has focused on the special problems of preserving ‘artifacts in use’. The separate spheres of conservation and traditional restoration form the basis of his analysis of the values and underpinnings of conservation. Address Department of Conservation–BHW The Colonial Williamsburg Foundation P.O. Box 1776 Williamsburg, VA 23187-1776 USA

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A CLEAR CASE OF PROFILING: DEFINING ARCHAEOLOGICAL CONSERVATORS IN THE U.S. Claire Peachey Abstract A questionnaire was sent out to archaeological conservators and archaeologists who perform conservation, to gather information about the background, experiences, and motivations of archaeological conservators educated or working in the U.S. Fifty percent of the conservator respondents have degrees in archaeology, anthropology, or ancient history. Forty percent of the conservator respondents attended a conservation degree program specializing in archaeological conservation, while several others were able to tailor their education to maximize their experience with archaeological materials and sites. The archaeologist respondents learned conservation of underwater materials in their archaeology degree programs. Most people have had a combination of positive and negative conservator-archaeologist relationships; many report positive experiences and increasingly positive attitudes toward conservation, but a lack of full integration within archaeology. Communication and mutual respect are the most cited characteristics of a successful relationship. A majority feel that more archaeological internships are needed, but that more archaeological conservation degree programs are not needed, partly due to lack of available jobs. Nearly all respondents feel that archaeologists should learn basic conservation theory and skills in their degree programs, with some difference in opinion as to how much treatment procedure should be included.

Therefore, many of the questions were deliberately general, so that people would elaborate in whatever directions were relevant to them. The intent was to gather some general information about people, and some personal viewpoints on issues, to get a slice of what conservators are thinking today about the field of archaeological conservation. Thirty-two people answered the questionnaire. Twentythree of those were members of OSG-Archaeology, representing approximately 30% participation of the 77 members of that group. Twenty-one respondents were female, 11 male. The questions and answers 1. What is your profession? (i.e., what do you call yourself?) Below are the titles that respondents provided, followed by the number of respondents. • Archaeological conservator, or archaeological materials conservator: 8 • Archaeological/objects conservator: 1 • Objects conservator: 6 (some combined with sculpture and/or archaeological fieldwork specialties) • Objects or art conservator with specialty in ethnographic and/or archaeological objects/materials: 4 • Conservator, objects conservator, or archaeological conservator, depending on the audience: 6 • Conservator: 5 • Archaeologist (who does conservation): 2 • Combined titles include one each of: professor of conservation, materials scientist, administrator, professor of archaeology, archaeological conservation program manager.

Introduction This paper developed out of a curiosity I had about several of my own assumptions about archaeological conservation and conservators. For example, I assumed that most archaeological conservators had education and training in archaeology, but did not know if that was true. I assumed that most archaeological conservators did not work solely on archaeological objects, but did not know that for sure. I knew that there had been some insightful articles written on the nature of archaeologyconservation interactions, and wondered about the experiences of individual conservators.

The questionnaire did not ask for details of employment, but most people provided that information, or it was inferred: • Federal government -3 • State government - 5 • Private practice – 9.5 • Museum - 3 • University – 5.5 • Private foundation - 1 • Historical society – 1 • Doctoral student – 1 • Not specified - 3

To get a glimpse into these and other issues, I drew up a short questionnaire directed at archaeological conservators educated or working in the United States. I sent this out to the American Institute for Conservation Objects Specialty Group’s Archaeological Discussion Group email discussion list (OSG-Archaeology). To include others who might not be members of OSGArchaeology, including archaeologists who perform conservation, I also sent it to the Conservation DistList email discussion list, the Sea-Site email discussion list, and to individual conservators and archaeologists. The questionnaire was simply a series of questions to elicit discussion of certain topics. Archaeological conservation has many different types of practitioners, and indeed the term itself is defined differently by different people.

The number of archaeological conservators in private practice was surprising. I had assumed that since archaeological collections tend to reside in institutions such as universities and museums, conservators working on those collections or on field projects would be employed by those institutions. However, several private 17

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS conservators make part or all of their living working on archaeological sites and collections.

One person has bachelor’s degrees in Library Science and Chemistry. Two did not specify their first degrees.

2. Do you consider yourself solely an archaeological conservator? Or are you a conservator who works on archaeological objects along with other materials? Few people (six) work only on archaeological materials. A few others (six) work mostly but not solely on archaeological materials. Most people work on a variety of object and material types. For some, it has depended on the job they have held, and has changed during the course of their career. Some said they would prefer to work mostly on archaeological materials, but can not, for economic or other reasons: not enough opportunities to make a living on only archaeological materials, or the collection in their institution is mixed so they have to work on the full range of objects and materials. As further explored in question #10, consistent jobs with reasonable salaries are difficult to find in archaeological conservation, so it is usually necessary to work on a broader range of materials.

Within this group of conservators who answered the questionnaire, there is a strong pattern of coming from an archaeology/anthropology academic degree (43%). Therefore, it is likely that these people went into conservation knowing the language of archaeology, the questions asked by archaeologists, and what archaeologists value in material remains. Of the 13 conservators who majored in Archaeology or Anthropology, eight attended University College London for their conservation degree, one attended Buffalo State College, one the University of Paris/Sorbonne, one New York University, one Cardiff University, and one chose apprentice study. Of the 30 conservator respondents, 25 attended a conservation degree program; 12 of these 25 attended an archaeological conservation program, in London, Cardiff, or Durham. Of those who did not get a degree in conservation, two got advanced degrees in Museum Studies, one in Archaeology, one in Sculpture, and one in Library Science.

3. Do you specialize within archaeological conservation? Most people do not specialize within archaeological conservation, though many people did say they have particular interests, or have more experience in some materials, or even are labeled as specialists by others.

The number of respondents receiving conservation degrees from each institution: • University College London - 9 • Durham University - 1 • Cardiff University - 2 • New York University - 8 • Buffalo State College -1 • University of Delaware - 2 • Queens University - 1 • University of Paris/Sorbonne - 1

4. How did you decide to pursue archaeological conservation? Responses to this question are incredibly varied -- as varied as each of our life stories is. However, there are some common themes that run through the responses received. Twenty respondents studied archaeology, anthropology, ancient history, or ancient art. Two respondents came into archaeological conservation through their museum work, one came to like it during conservation school, and one person got into it “for the fun of it (at least at the beginning).” Most people noted a combination of interests and influences that led to archaeological conservation, and these include: materials science and analysis, history and antiquity, working on digs, making things, preservation, chemistry, increased challenge of archaeological materials, use of problemsolving skills, and the fact that archaeological conservation “is focused not only on the object in the past, but its current and future lives.” The opportunity to combine interests in science, art, and archaeology was appealing to some people.

6. Did your desire to be an archaeological conservator affect your choice of conservation (or other) education? Twenty-five people said yes (or mostly yes), and seven said no. In the “yes” crowd, there were some who noted that they also took into account finances in making a final choice of conservation program, so they did not attend one of the specialized programs in the United Kingdom. Two people chose apprenticeship and internship training because there was no archaeological conservation program in the U.S. One of the “no” people said the ethnographic concentration in their program was more important than an archaeological concentration. For the other “no” people, two did not know about conservation when they began their studies, one became interested in archaeological materials during conservation school, and one chose their program because it was good in many areas.

5. What degrees do you hold, and in what subjects? Included in these numbers are only the 30 people who identify themselves as conservators, leaving out the two people who identify themselves as archaeologists. Of those 30 people, 13 have a bachelor’s or master’s degree in Archaeology or Anthropology. Another two have related degrees, in History with an emphasis on ancient Mediterranean civilizations, and in Classical Civilization. Another seven got their bachelor’s degrees in Art History, and of those, one noted a specialization in ancient art. Five have bachelor’s degrees in Studio Art.

7. If you did not attend a specific study program in archaeological conservation, do you feel that your education program prepared you well to be an archaeological conservator? Since 12 respondents did attend a degree program dedicated to archaeological conservation, this left 20 18

CLAIRE PEACHEY: A CLEAR CASE OF PROFILING: DEFINING ARCHAEOLOGICAL CONSERVATORS IN THE U.S. noted the need for dedicated programs at all levels, including PhD.

who did not. Fifteen of those 20 people answered yes to this question. They were able to get training in archaeological materials in their programs through elective courses in archaeology-related subjects, by choosing archaeological objects to work on, and through independent study, internships, and fieldwork on excavations. Several people noted that faculty or mentors knew of their interest and helped them to shape their study programs accordingly. The archaeologist respondents noted that their degree programs in underwater archaeology combine archaeology and conservation. Other factors that prepared respondents well were chemistry studies, craft and mechanical abilities, and the ability to improvise. One person noted that their program prepared them well enough to work on archaeological objects in a museum, but not to work in the field and improvise when conditions are less than ideal.

Regarding internships, a large number of people noted that more on-site opportunities are needed, so that conservators can learn what it is like to work in the field. It was noted that since it is not possible to learn everything in a two- or three-year degree program, internships and/or continuing education are critical, to learn about issues such as specific burial problems, collaboration, logistics of excavation, types of decay, handling bulk collections, site management, field documentation, and archaeology-oriented analyses. Many noted that internships should be paid. One person commented that having more internships is great, but eventually conservators have to get jobs. A dissenting opinion noted that more field internships are really not necessary, since most people do not end up doing archaeological conservation once they get a job. For archaeological collections in the U.S., much of the work is collections management, assessments, consulting, repackaging, and general preventive conservation.

Two people noted that although they had a special interest in archaeological conservation, they attended a more general conservation degree program, and were glad in retrospect that they received a broader range of teaching and experience than they might have in a specialized program. Related to this, two people said that they attended an archaeological conservation degree program, but would not advise others to specialize in this way, for the same reason.

9. Are you satisfied with opportunities for continuing education relevant to archaeological conservation? Judging by the answers, people defined continuing education as conferences, courses, further graduate study, generally learning through experience, and keeping up with literature. Opinions were split approximately evenly: nine respondents felt there are adequate opportunities, 14 felt there were not enough opportunities, and nine were more or less satisfied, or have no opinion.

8. Do you feel that more education programs specializing in archaeological conservation are necessary? More internships in archaeological conservation? Of those who had clear opinions on these questions, the most common answers were no, more conservation programs were not necessary (14), and yes, more internships are necessary (18).

Many people noted that there are some good symposia and courses, including international ones, but that individuals do not always have the time or funding to go to them. On-line training was suggested. Others felt there are too few regular, consistent offerings, and that there is a need for “mid-career courses specific and germane to archaeological conservation.” Another opinion expressed was that in order to offer useful continuing education opportunities in archaeological conservation, it is necessary to identify “skill areas that aren’t being met in the training programs.” Some noted that courses and training for general objects, or even other conservation specialties, can be applied to the archaeological field.

Most of those who said that no more programs were necessary referred to the lack of jobs in the profession; even some who said yes also expressed this reservation. Other opinions expressed were that a competent objects conservator can learn archaeological conservation, and that competent conservators can come from archaeology programs. A number of people expressed expectations that the new UCLA program will fill a gap in conservation education in the U.S., and that since this program will train archaeologists alongside conservators, it will lead to more collaboration and an increased need for conservators.

Some of the ways that people keep current with the field include being self-motivated, keeping up with literature, networking, membership in professional organizations that promote exchange, attending conferences and symposia, participating in teamwork and research projects, and working on a varied range of projects and materials.

Six people answered definitively that more programs are necessary. One person noted the need for a program that has a focus on American material and American microenvironments. One person noted the dearth of archaeological theory and research to be found in conservation literature, and continued: “…it would be useful to incorporate such theory into conservation to broaden our role from being technicians who stabilize the materials of construction of artifacts to becoming preservers of their current values and meanings.” Two

Several suggestions were made for topics for continuing education: electrolysis, lifting, freeze-drying, use of new technologies, site management, scientific analyses, practical workshops, learning more about what 19

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS archaeologists value, conservation planning strategies for excavations, “ways to educate field archaeologists and field directors about conservation and preservation planning,” and “constructive ways to approach and mitigate large-scale conservation problems already in progress due to lack of funding.”

Also noted is that many institutions with collections do not have the budget or staff for conservation; getting funding for conservation or even general preservation of existing older collections is difficult; conservation, curation, and other activities beyond the fieldwork phase are not glamorous enough to attract funding; and much archaeology is done by CRM (cultural resource management) firms, many of which do their own conservation instead of hiring conservators. One respondent noted the impression that archaeology-related conservation jobs are not always advertised in the same way as other conservation jobs, but are sometimes part of a word-of-mouth network instead.

10. What do you think of the job market for archaeological conservators? One can likely guess the general answer to this question. Here are some quotes: • “What job market??!!” • “It stinks.” • “There is a good job market for archaeological conservation STUDENT VOLUNTEERS.” • “Poor.” • “Very poor.” • “Practically non-existent.” • “Are you kidding, it sucks.” • “Difficult!” • “I think it’s dismal!” • “Miserable.” • “…poor unless one is able to work like a dog for very little money.”

A number of people opined that trained and experienced conservators charge far less than their worth and need to request better salaries than they do. By working for low salaries, it makes it harder for everyone. Related to this are comments that lower-paid, lesser-qualified technicians or students with basic training get hired instead of experienced conservators who charge more. One person astutely noted that the result of this is that many archaeologists never see professional archaeological conservation. Another person noted that archaeologists want a conservator to train their staff and volunteers to do the work themselves.

Permanent jobs working on archaeological materials full time are few, which is why so many people work on other materials as well. As one person said, “If I wasn’t in private practice doing something other than just archaeology, I’d be out of business.” In order to do fieldwork in particular, it is necessary to have another source of income such as from a museum, university, or private practice, or to find one’s own funding to join a project.

A few people responded with optimism that the situation may be changing as more archaeologists are seeing the positive effects of conservators in the field. In particular, as more archaeological conservators are trained in the U.S. (through the UCLA/Getty program, for example), more will be available, and more jobs may be created. Also noted was that “museums are increasingly privatizing work, so if one is in private practice and flexible, there is a living to be made.” And some people noted that despite the difficulties in the job market, they have been able to find work in the profession.

People noted that there are more jobs than there used to be, but in general, jobs are low-paid, there is not much opportunity for “moving up,” usually there are no benefits, jobs are short-term and temporary, jobs are unstable due to soft funding from year to year, and/or the work requires frequent relocation. Some people noted that these issues ultimately drive people to leave the profession as they gain family and other responsibilities.

11. Do you work/have you worked on field excavations as a conservator? All 32 respondents answered yes (as expected, given the target audience of the questionnaire). 12. Do you work with archaeologists to plan before an excavation? Or do you get called when a field project is in progress or finished? Most people (19) responded that they have done both: sometimes they have been involved in planning, and sometimes they get involved during or after the excavation. A few responded that the latter is more frequent. Six responded that they only get called during or after the excavation. Two people noted that being involved in planning does not necessarily translate into being involved in long-term decision-making.

Many people offered reasons for the poor job market in the profession. Most often cited is lack of funding for conservation. This is ascribed to (among other things) archaeologists not being aware of the need for conservation, not being interested in having it done, or feeling that fieldwork should be unpaid. This relates to the difficulty of funding archaeology in general; there is high competition for limited funding, so little incentive to add conservation to the budget. Many university archaeologists go into the field with unpaid or low-paid graduate students (who compete for the opportunity to go), so again may not feel the need to pay for a conservator, especially if conservation is not highly valued. This is discussed further in the discussion of questions #13 and #14.

A few respondents noted differences between working with academic institutions or museums, and working with CRM firms. Universities and museums tend to involve conservators in planning moreoften than do CRM firms, which will contact a conservator only for unusual or difficult artifacts that have already been 20

CLAIRE PEACHEY: A CLEAR CASE OF PROFILING: DEFINING ARCHAEOLOGICAL CONSERVATORS IN THE U.S. and coin cleaner, no interest in technical information or analysis, expecting objects to be conserved as fast as possible, not being called to the field for a complex lift, lack of communication between the field and the lab, being left out of the publication phase, not getting acknowledged for contributions, being viewed as intrusive, expensive, and an inconvenience, being considered unreasonable and pushy and impractical, and archaeologists not thinking they have a conservation problem and not having a sense of responsibility for long-term preservation. An archaeologist respondent cited some conservators’ “holier-than-thou” attitude and unwillingness to work closely with the archaeologists.

excavated. A difference between underwater archaeology and terrestrial archaeology was also noted, in that conservation is planned for in underwater archaeology, “where all artifacts are presumed unstable,” while in terrestrial archaeology, the conservator’s role is more likely to be as “a technical consultant to solve the unexpected problem.” 13. Do you find that archaeologists value conservators? Answers to this question varied from “no” to “very much so.” Most people were generally positive (14) or stated some variation of “yes and no,” “it depends,” or “some do, some don’t” (14).

Positive experiences occur when both parties value each others’ expertise and when the work is truly collaborative. Above all, the two mostly frequently cited factors in a successful archaeologist-conservator relationship are communication and mutual respect. Others include: being interested in each other’s work, getting along personally, having realistic expectations, forging research collaborations, behaving with professionalism and diplomacy, being flexible and practical, being accessible, actively participating, being involved in planning, understanding the context in which the conservator is working (i.e. as a specialist within archaeology), understanding the parameters within which the archaeologist is working (research design, logistics, funding), not being dogmatic, and making decisions cooperatively.

On the negative side, some archaeologists see conservators as “budget blowers,” “restrictive in our recommendations,” and possessing a tendency to scold archaeologists. Other repeatedly noted comments include that conservators are misunderstood, the archaeologists feel they can do the work themselves, and archaeologists are not familiar with the benefits of conservation. Others noted that archaeologists may value conservators individually, but not as a culture, and this is reflected in the lack of funding allocated to conservation; another opinion turned this around, saying archaeologists value conservators, but lack of funding limits their use of conservators. Four people noted that the situation seems to be changing for the better. One respondent noted that “once an archaeologist has had the experience of working with a professional conservation in a cooperative setting, he or she will often value other conservators and their contributions.” Other comments observed that relationships takes work, they depends on the individuals, archaeologists value conservators by the end if not at the beginning, and they value them when the conservator becomes instrumental to the archaeologist’s research. As noted above in the discussion of question #12, some respondents commented that museums tend to value conservators more than CRM firms do, and that underwater archaeologists value conservators more than terrestrial archaeologists do.

Sixteen people felt there were definite problems or misunderstandings between archeologists and conservators, seven felt more or less that there are problems, one did not feel there are problems, three did not know, and five gave no specific answer. Many felt that any problems or misunderstandings are a result of not fully understanding each other’s professions: the archaeologists’ incomplete understanding of conservation issues and what conservators can do, and the conservators’ incomplete education in archaeology methods and theory. The two groups approach the materials, sites, and objects from different perspectives, and have different priorities and goals. Another frequently cited issue is that conservation takes time and money, which archaeologists do not have enough of. Many feel that the problems start in the archaeology training programs, where there is little active conservation education, which translates into lack of interest and lack of funding; archaeology undergraduate and graduate students need more interaction with conservators so they will understand how conservation can add to their knowledge base. Also, one person noted that there are so many more archaeological field schools than there are conservators to attend them. One respondent noted that archaeologists see conservators to be out of step with current archaeological theory, “so our role is limited to the technical issues of preserving the materials of construction of artifacts and not the meanings of the ‘whole artifact’.”

14. Have you had any particularly positive or negative experiences with archaeologists? What do you think are the ingredients for a successful archaeologist-conservator relationship? Do you feel there are problems with archaeologist-conservator cooperation in the U.S., in general? If so, what do you believe is the basis of those problems? Seventeen people responded that they have had both positive and negative experiences with archaeologists; another ten report positive or mostly positive experiences, and five gave no specific answer. Examples of negative experiences given by respondents include not being invited to the excavation area, having the conservation funding cut, using the conservator’s name and credentials but not doing any conservation, expectation of the conservator being only a pot mender 21

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Another seven respondents feel it is beneficial to have some training or experience in archaeology, implying or stating that it is not necessary, however. Some feel that training in a related field is sufficient, or knowledge of the materials technology of the culture being investigated, or art historical technical knowledge. One feels that communication skills and knowledge of the goals of the specific project are of primary importance.

Other reasons given include: many archaeologists feel they can use a recipe book and do conservation themselves rather than call a conservator; archaeologists do not respect conservators’ training and abilities; conservators run around saying “No! Don’t do that with my objects!”; lack of availability of trained conservators; “CRM culture”; archaeologists feel the artifacts do not warrant conservation attention; and archaeologists sometimes excavate artifacts without thinking of the cost and difficulty of treatment.

16. Do you feel that archaeologists should be taught some level of archaeological conservation as part of their archaeology degree? What specific topics or skills? Almost everyone answered yes to this question, and overall suggested a similar group of topics and skills to be taught. At a minimum, it appears that conservators would like archaeologists to be taught handling skills, the importance of conservation, and knowing when to call a conservator.

One view expressed is that anthropological archaeologists have less of an interest in material culture than classicists and historical archaeologists do, while another is that anthropological archaeologists are more receptive of conservation. This seems to emphasize the view noted by a number of people that so much of the relationship boils down to the interactions between individuals. Also repeated were the opinions that in marine archaeology, the conservator is part of the planning process and an integral part of the team more often than in terrestrial archaeology; and that the same holds true for projects run by museums or institutions as compared to CRM firms. People also noted a difference between “old school” archaeologists and newer graduates, and feel (as noted above) that things are changing for the better as more archaeologists have contact with conservators and see the benefits of conservation.

Other topics most cited include: • Basic understanding of what conservation is, and what can be gained by conservation input. • Planning and budgeting for conservation and preservation before the excavation. • Basic understanding of the deterioration of materials, and how burial and excavation affect different materials. • Assessment, excavation, stabilization, sampling, handling and packing techniques, including using the right materials. • Field documentation useful for conservation. • Recognizing when it is necessary to call a conservator, and where to find an appropriate one. • Long-term preservation issues and responsibilities.

15. Do you think it is important for an archaeological conservator to have academic training in archaeology? All but one person answered this question by saying yes, with various degrees of enthusiasm. Twenty-two people feel that archaeological training is certainly necessary. The archaeological conservator does not have to have a degree in archaeology, but must acquire a theoretical and methodological framework and get field excavation experience. One respondent commented that archaeology training is more important for conservators doing fieldwork, and “less so for conservators working on archaeological museum collections which are largely ignored by archeologists.” Another pointed out that if conservators do not keep current with archaeological literature, or understand the research goals of a project, for example, the research element of the conservator’s contribution is lost.

Opinions varied on the subject of teaching treatment procedures to archaeologists. The main concern expressed is that treatment procedures often get passed down as recipes and steps, without the thought process behind assessing objects and choosing a particular set of procedures from a wide range of possibilities. However, others point out the unfortunate reality that many excavation projects do not employ field conservators, and that so many condition problems can be prevented if archaeologists have enough knowledge to get the artifacts out of the ground and stabilize them properly. Many people suggested that archaeologists should be taught basic preservation methods, but with a clear emphasis on when it is necessary to contact a conservator. Different people suggested different skills, including desalination, wood identification, xradiography of iron, safe rudimentary cleaning, consolidation in situ prior to lifting, block lifting, pottery joining, and basic conservation methods for different types of material.

The reasons put forth for having a theoretical and field background in archaeology are many: to be able to speak the same language, to understand how archaeologists view the physical artifacts (both shortterm and long-term), to know what kind of information archaeologists are looking for, to be able to make sound conservation decisions based on the research potential of the artifact, to be taken seriously, to foster mutual respect, to learn how to collaborate in managing and determining priorities in a large collection of excavated material, and to learn the documentation systems used by archaeologists in order to integrate conservation information.

Closing Responses to a questionnaire directed at archaeological conservators working in or educated in the United States 22

CLAIRE PEACHEY: A CLEAR CASE OF PROFILING: DEFINING ARCHAEOLOGICAL CONSERVATORS IN THE U.S. provide a sample of opinions and experiences of these conservators. A summary of some of the responses shows the following patterns: Fifty percent of the conservator respondents have degrees in archaeology, anthropology, or ancient history. Forty percent of the conservator respondents attended a conservation degree program specializing in archaeological conservation, while several others were able to tailor their education to maximize their experience with archaeological materials and sites. The archaeologist respondents learned conservation of underwater materials in their archaeology degree programs. Most people have had a combination of positive and negative conservatorarchaeologist relationships; many report positive experiences and increasingly positive attitudes toward conservation, but a lack of full integration within archaeology. Communication and mutual respect are the most cited characteristics of a successful relationship. A majority feel that more archaeological internships are needed, but that more archaeological conservation degree programs are not needed, partly due to lack of available jobs. Nearly all respondents feel that archaeologists should learn basic conservation theory and skills in their degree programs, with some difference in opinion as to how much treatment procedure should be included. A wide variety of opinions was expressed, and not all responses fit into the generalized summary above. Many of the issues brought up by respondents are substantially similar to those discussed in the profession over the past twenty years, or longer. This questionnaire provided the opportunity to not only gather some education and employment data about archaeological conservators, but also to present the personal insights of individual conservators. Biography Claire Peachey is an editor for the Navy. Previously she was a conservator in the Underwater Archaeology Branch of the Naval Historical Center, where she works on waterlogged archaeological artifacts and historical maritime objects. She has a combined education and career in terrestrial and underwater archaeology (MA Anthropology/Nautical Archaeology, Texas A&M University) and archaeological conservation (University College London). Address Naval Research Laboratory 4555 Overlook Avenue, SW Washington, DC 20374

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TRAINING ARCHAEOLOGICAL CONSERVATORS Virginia Greene Abstract In 2000, the American Institute for Conservation created a task force to take the first step in the process leading to certification: defining the knowledge and skills necessary for all professional conservators. Each Specialty Group in AIC has now formed a committee that will comment on these basic competencies and eventually define the specific knowledge and skills needed for each branch of conservation. The current paper is a personal response to this process: an assessment of the specialized knowledge needed by an archaeological conservator, a brief look at whether the current US training programs are addressing the requirements, and suggestions for changes that might be made to strengthen the training of archaeological conservators in the US. Introduction In 2000, the American Institute for Conservation (AIC) created a task force that was charged with the responsibility of defining the knowledge and skills necessary for a professional conservator. The Qualifications Task Force produced a document titled ‘Defining the Conservator: Essential Competencies’ (AIC 2003). This document defines a dozen ‘areas of competency’ ranging from the philosophical to the severely practical, including Terminology; History, Ethics and Philosophy; Examination Methods; Health and Safety; and Documentation. With this as a foundation, each Specialty Group in AIC has formed a committee that will comment on the basic competencies and eventually define the specific knowledge and skills needed for each conservation specialty. The current paper, partly stimulated by this process, is a personal statement founded on over 35 years of experience and not a few frustrations. It is an attempt to define the specialized knowledge essential for an archaeological conservator, followed by a brief look at whether the current US training programs are providing adequate preparation in this area. The paper concludes with suggestions for changes that might be made to strengthen the training of archaeological conservators in the US. No attempt was made to carry out a comprehensive survey of any of the constituencies involved: conservators, archaeologists, or training programs. That is a very large task that will be part of the official process. This paper represents the views of the author, and also reflects the opinions of four other conservators with wide experience in the conservation of archaeological objects, both in the field and in the lab; the views of six archaeologists working in four different parts of the world, all of whom have worked on site with conservators; and information obtained from five individuals who are program directors or faculty members at New York University Institute of Fine Arts, Buffalo State College, the Winterthur/University of 25

Delaware Program and the new UCLA/Getty program. Biases and limitations will eventually disappear as AIC and the Objects Specialty Group solicit the views of a much larger number of people. One of the more interesting biases—not in any way deliberate—turned out to be the fact that all of the archaeologists had had positive experiences with conservators. This may not be a representative sample, but it certainly ensured an appreciation of the role of conservation in archaeology. The author and three of the other four conservators—all personal friends and colleagues of long standing—were trained at the Institute of Archaeology at the University of London. This bias, reflecting the limited opportunities available in the US 25 to 35 years ago, will certainly disappear in the final report. Archaeological conservation: essential knowledge For a definition of conservation, the reader is referred to other sources (AIC 2003). For purposes of this paper, archaeological conservation is defined as the subspecialty of conservation that is concerned with the treatment and preservation of objects excavated from archaeological sites, including both work in the field and in a museum setting (see, e.g., Cronyn 1990: 1). It is the only specialty which involves work in two very different environments: museums (as well as regional centers and private labs), with all the expected amenities; and archaeological excavations, including in situ conservation and work in field labs. The common use of the term ‘archaeological conservator’ does not always recognize this dual reality. All too often it refers to a conservator of any background and training who works in a museum on previously excavated objects. The problem was specifically mentioned by one of the conservators, who dislikes the term, as it ‘still carries the legacy of the profession having grown up with its roots in a museum context’ (Beaubien 2005). Even an archaeological conservator trained in the UK tradition, where a student was expected to develop expertise in both field and museum conservation, can fail to clearly define the dual responsibilities of an archaeological conservator. Elizabeth Pye, in Caring for the Past: Issues in Conservation for Archaeology and Museums, includes a definition of archaeological conservation which says nothing about field work (Pye 2001: 12). Her extensive list of the environments in which conservators work does not include archaeological sites, in spite of the fact that she is clearly aware of the possible effects of excavation on objects, and describes situations in which immediate conservation contributed to their survival (Pye 2001: 19, 128–129). When asked about the knowledge and skills necessary

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS an anthropologist or archaeologist as unethical, as it might destroy evidence about the way in which the object was used. It is not, however, necessarily a question of ethics. An inpainting style entirely within the bounds of current practice may simply be unacceptable to a curator with a different approach to the objects.

for archaeological conservation, archaeologists and conservators were generally in agreement. The first area mentioned was almost always technical expertise specifically related to archaeological material and to work on a site. All conservators need to have a broad knowledge of materials and technology and how these materials respond to specific environmental conditions. In the case of archaeological conservators, this technical knowledge must include an understanding of the effects of a wide range of burial conditions (dry, intermittently wet, waterlogged, acidic or alkaline, etc.) on both inorganic and organic materials and a grasp of the possible effects of excavation on these materials. Practical knowledge must include not only treatments suitable for a well-equipped lab but specific techniques useful on excavations, such as block lifting, methods of in situ consolidation under a variety of conditions, conservation materials suitable for field work in different environments, and the design and management of a field lab.

Since the first US museums to establish conservation laboratories were art museums, and until this year all US training programs had a primary emphasis on art history as the academic discipline needed for admission, it is not surprising that a majority of conservators trained in the US will see objects through the lens of an art historian rather than an archaeologist or anthropologist. The differences come into sharper focus as soon as field work is taken into consideration. Experienced field conservators as well as archaeologists who have worked closely with conservators are clearly aware of the fact that the goals and practice of field conservation are not the same as those of museum conservation (O’Connor 2005; Sharer 2005). Conservators and archaeologists may need to negotiate a compromise between the demand of the archaeologist for extensive recording (once the information is lost, it is lost forever) and the knowledge of the conservator that immediate removal and treatment is needed to preserve the objects and the information which can later be recovered from them (O’Connor 2005; Price 1984: 5; Cronyn 1990: 5). It is rarely possible to devote extensive time and resources to a single object, or to do extended research on the best type of adhesive or consolidant; objects often must be consolidated or repaired under less than ideal conditions with limited supplies. In spite of this, the object may or may not ever receive any further treatment, and in some cases objects will be recorded and reburied rather than preserved (O’Connor 2005). These are conditions that some conservators cannot easily accept. Many conservators who are qualified to work on archaeological materials in a museum setting may not have the necessary training and experience—or the temperament—to work on site.

Considered by both archaeologists and archaeological conservators to be as important as technical knowledge was an understanding of the goals and fundamental principles of modern archaeology, and an appreciation of the realities of work on an excavation: limited time and money (normally even more stringent than in a museum), the lack of second chances, and difficult living and working conditions, as well as the problems of dealing with local archaeologists, conservators, and government officials. Inadequate resources and the need for diplomacy may be part of the experience of any conservator, but in a field situation these difficulties are often exacerbated (Zettler 2005; O’Connor 2005; Adams 2005; Rose 2005; Price 1984: 1). All conservators would agree that it is not possible to be a professional conservator of paintings, or decorative arts, without some knowledge of art history. This means not only the ability to recognize different styles of work, and a knowledge of technology, but an understanding of how art historians look at works of art. The same holds true for conservators of archaeological objects. The relationship between archaeology and archaeological conservation has long been understood in the UK (Cronyn 1990: 5–6; Price 1984: 1), but has often not been appreciated in the US.

The majority opinion among both conservators and archaeologists was that students interested in archaeological conservation should have taken at least one undergraduate-level course in archaeological method and theory, and have spent at least one summer on an excavation or at an archaeological field school (Beaubien 2005; Sease 2005; Koob 2005). Additional academic background in archaeology was seen as useful but not essential. In the area of studio art prerequisites, priority should be given to courses in ceramics and metalworking rather than drawing and painting.

Part of the problem many conservators have in understanding the relationship between archaeology and archaeological conservation is the fact that many excavated objects, once in a museum, can be viewed and studied both from the point of view of art history and of archaeology. However, even in a museum context, the needs and concerns of archaeology may not agree with those of art history. What is appropriate for an object in an art museum—for example, in terms of cleaning, loss compensation, or inpainting—may not be appropriate for the same object in an archaeology museum. Treatments which an art historian would find not only acceptable but preferable on aesthetic grounds, such as cleaning that removes pre-collection surface deposits, may be seen by

Some of the conservators and archaeologists (including the current head of the Buffalo program, who is also an archaeologist) felt that field experience was as important as or more important than any academic background in archaeology (Sharer 2005; Zettler 2005; Beaubien 2005; Sease 2005; Grant 2005; Peña 2005). 26

VIRGINIA GREENE: TRAINING ARCHAEOLOGICAL CONSERVATORS [The] litmus test for an archaeological field conservator...is field recovery....Someone who has not...come into archeo[logical] conservation with some experience of the recovery dilemmas presented by excavation is not ready [for field work], and it would be even better if there was some specific training in this respect (Beaubien 2005).

2005). One of the conservators added that ‘the archaeological conservator has to know how to make whatever they have done part of the central documentation of the project’ (Beaubien 2005). Conservation reports included as appendices in a site report are not a substitute for incorporation of conservation information in the excavation data base. When talking about the qualities that are important on a dig, most of the archaeologists as well as the conservators mentioned the need for diplomacy, flexibility, a sense of humor, the ability to work with people from different cultures, and a willingness to learn. Several also pointed out that these qualities are equally important for archaeologists. (Rose 2005; Sharer 2005; O’Connor 2005). One of the purposes of summer field schools and volunteer work on excavations is to give interested undergraduates a taste of reality before they decide whether they want to pursue archaeology as a career, and it should serve the same purpose for prospective archaeological conservators.

The majority opinion—and the author strongly concurs—was that a combination of academic and field work was essential preparation for training in archaeological conservation. It is not necessary to have a degree in archaeology, but it is most definitely necessary to ‘speak the language’, to be able to converse intelligently with archaeologists (Sease 2005; Cronyn 1990: 5–6; Price 1984: 1). A conservator who does not understand the archaeologists’ concerns and interests will not be able to do his/her job, and the result will quite probably be hostility on the part of the archaeologist toward conservation. The author does not accept the argument that it is possible to easily train any conservator to do work in the field (Rose 1975). The shortage of properly trained field conservators may make this a tempting solution, but does not make it a professionally responsible one.

Once a student is accepted into a program, the conservators interviewed were united in the conviction that there is an absolute need for students to have at least one, and possibly two, seasons of field work supervised by an experienced field conservator (Sease 2005; Grant 2005).

Archaeologists and conservators also agreed that previous detailed knowledge of the cultural history of an area was not needed. Archaeological conservators often work in more than one geographical area. With a basic knowledge of archaeological principles and practice, and the help of the archaeologist, an archaeological conservator should be able to learn about any specific area without difficulty, including local environmental conditions and materials likely to be found, and to acquire an understanding of previous work done at the site or in the area (Grant 2005; Wegner 2005; Rose 2005; Price 1984: 4).

US training programs: prerequisites The following two sections look briefly at program prerequisites and curriculum. Are applicants expected to have previous course work and/or field experience in archaeology? Is it possible for students without the prerequisites to take archaeology courses as electives? Does the program curriculum include specific information on burial environments, the consequences of excavation, and field techniques? Are there opportunities to work on excavated objects, preferably in collaboration with archaeologists and archaeological conservators? Is adequately supervised conservation experience in the field not only available but required?

One of the easiest ways for a prospective archaeological conservator to acquire experience is through a summer field school in archaeology. A good field school will provide not only practical experience in excavation techniques, recording methods, and processing of finds, but introduce the participants to the theoretical foundation of field archaeology. It will also provide firsthand experience of the difficult living and working conditions on most excavations. An alternative source of experience is an excavation which accepts untrained volunteers.1

The UCLA/Getty program, specifically designed to teach archaeological and ethnographic conservation, has just accepted its first class of six students, and it is not at this time possible to consider any aspect of the program except the admission requirements as stated on the website (UCLA/Getty 2005). These are generally similar to prerequisites for the other US programs, with the exception of the fact that UCLA/Getty requires some course work in archaeology and/or anthropology. The academic coordinator stated that ‘if a student is primarily interested in archaeology, they will likely have at least two supervised [field] seasons, and related course work, under their belt’ before admission (Pearlstein 2005).

An introduction to field recording is a particularly useful aspect of experience on site. One of the archaeologists interviewed specifically mentioned that both archaeologists and conservators do a great deal of record keeping, but not in the same way, and conservators need to understand how archaeologists keep records (Sharer

None of the other US programs were set up with the intention of teaching archaeological conservation as a specialty, or, in the case of Winterthur and Buffalo, teaching it at all. (For simplicity, programs will be referred to by the shorthand generally used in

1 A number of informative websites are accessible via Google; enter ‘archaeological excavation volunteer’.

27

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS are handled on a case-by-case basis. No elective courses in archaeology are offered by Buffalo State College, nor is there room in the program for an elective of this kind (Peña 2005).

conversation: ‘NYU’, ‘Buffalo’, and ‘Winterthur’.) None offer a major or a formal minor in archaeological conservation; students with an interest in this area major in Objects. All three programs look for a background in archaeology for students who express an interest in archaeological conservation at the time of application, but none have required prerequisites. The only program with a specific prerequisite for a major field is Winterthur, where applicants with an interest in furniture must show evidence of adequate skills in cabinetmaking, as the faculty discovered that there was simply not time to teach these skills along with the other courses (Norris 2005; WUDPAC 2005a). For all applicants, ‘general art and craft courses are required so it has not been a specific problem with the other disciplines as of yet’ (Norris 2005). From the author’s experience of the admissions process at Winterthur, applicants with declared interests are expected to show relevant craft skills, as sewing and/or dressmaking for those interested in textiles, and papermaking and/or bookbinding for applicants interested in paper.

At NYU, all applicants must have substantial academic preparation in art history, but evidence of a background in archaeology is considered a plus, ‘particularly for students who have identified archaeological conservation as a goal’ (Marincola 2005). It is clear that Winterthur, Buffalo, and NYU all take a student’s background into account, but on a very individual and ad hoc basis. How rigorously the process screens out or discourages those without a suitable background is uncertain. US training programs: curriculum Winterthur originally did not include any curriculum component related to archaeology or ethnography. However, for the last 15 years or so the program has consciously widened its focus. The change reflects both student interest and a desire on the part of the faculty to offer objects majors a more varied selection of treatment projects (Norris 2005).

Winterthur has no required prerequisites in archaeology, but would look for such courses if an applicant expresses an interest in archaeological conservation. The student would be considered ‘an objects major with a special interest in archaeological conservation’ (Norris 2005). An elective course in archaeology is available but not required.

Burial environments and excavation ‘are covered in both the Organic and Inorganic Block[s], although perhaps not in the...detail they would be at a school that focuses specifically on archaeological materials. The issue is also addressed as they undertake an archaeological conservation project during their second year’ (Pouliot 2005). Course work is taught by standing faculty who may or may not have specialized training in archaeology, anthropology, or field conservation. All objects majors at Winterthur must do treatment projects both on an archaeological and an ethnographic object. The latter are partly supervised by the author; archaeological projects are partly supervised by an archaeologist at the Delaware State Museum.

Most [students] who are interested in archaeological materials have had some exposure to this subject and generally conservation experience too...in almost all cases that I can think of those who have been especially interested in archaeological materials have come to the program with experience... (Pouliot 2005). Buffalo will allow students interested in archaeology or ethnography to replace over half the required semester hours in art history with courses in ‘archaeology and/or ethnography/ anthropology...emphasizing material culture’, and

Winterthur students take a course in technology and materials science but it does not necessarily include material specifically relevant to archaeological objects. Students can select an archaeological object for their required technical study project, and one of the available electives allows students to set up independent study projects on a wide variety of subjects, including those related to archaeology. ‘Those who are especially interested often will [also]...focus on archaeological experience in their summer or third-year internships’ (Norris 2005; also Pouliot 2005).

Although they are not admission requirements, applicants planning on a career in one of the following specialties are encouraged to take one or more of the indicated courses...before admission: • Ethnographic/archaeological conservation: introductory courses in ethnology, physical anthropology, zoology and botany; archaeology, technical drawing/documentation techniques for the archaeologist and anthropologist...(BSC 2005).

Archaeological conservation was included in the curriculum at Buffalo in 2004; ethnographic conservation had been added several years earlier. Student interest, as well as recognition of the need for training in these fields, led to the changes (Beaubien 2005).

The current director of the Buffalo program, who is an archaeologist, said that it is rare for a student to want to go into archaeological conservation without a background in archaeology (including some field experience), and she would not encourage it. Requests

Courses at Buffalo include information on materials and technology, including archaeological objects, burial 28

VIRGINIA GREENE: TRAINING ARCHAEOLOGICAL CONSERVATORS experienced conservator. However, any student with previous archaeological experience might work alone as a conservator on a ‘simple site’ (Peña 2005).

environments, consequences of excavation, and field techniques. These are taught both by standing faculty and an experienced archaeological conservator who is adjunct faculty (Beaubien 2005).

At NYU, field work is available for all students, whatever their background.

NYU, though considering itself an art history program (Marincola 2005), has always included an archaeological component, especially for objects majors. The curriculum, both theoretical and practical, in archaeological and ethnographic conservation was expanded and enhanced in1988 and again in 2002. Students can also ‘investigate areas of particular interest through independent study projects’ and work on excavations is encouraged (NYU/IFA 2005a).

All students are offered the chance to work on site, and many do. It is expected of students who have declared a special interest in objects conservation...all objects majors should have the sense of issues on site. Before students go on site the first time, they are required to take a weeklong, intensive course that introduces them to the issues of conservation on a dig (Marincola 2005).

At NYU, ‘Every student learns about the technology of all common art media, including archaeological and ethnographic objects, in the core curriculum. In the past 8–10 years we have also offered upper-level courses in inorganic and organic archaeological and ethnographic objects’, including both technology and treatment (Marincola 2005). One of the core courses includes information on burial environments and an extended discussion of the consequences of excavation. The detailed course descriptions suggest that the information provided is comprehensive. Independent study courses for third-year students also offer the possibility of work on archaeological materials. In addition to regular faculty with expertise in these areas, archaeological and ethnographic conservators are brought in to teach specific courses.

This special course was started in 2002 and is taught by a combination of standing faculty and outside conservators.2 All have excavation experience and many specialize in archeological conservation. A vast amount of material is included, possibly too much for one week. However, it is structured and consistent, and includes specific information on both inorganic and organic materials that might be found on the sites to which students are going (Sardis, Samothrace, Aprodisias); field techniques such as lifting, on-site consolidation and reburial; packing and storage, documentation, lab practice, and so on. Considerable effort is expended to ensure that students are properly supervised at all sites. At Sardis they often return for a second season where they help supervise the first-year students.3

Even with a maximum use of electives, summers, and the third-year internship, courses and lab work related directly to archaeological conservation is a small part of the student’s total experience, compared with students who attend a specialized program. Nonetheless, any objects major who took advantage of the available opportunities would be able to work on excavated material in a museum setting in an intelligent and professional manner. Work on excavations is another issue altogether.

The website for the UCLA/Getty program, surprisingly, states that supervised field work, even for students interested in archaeological conservation, is ‘preferred but not required’ (UCLA/Getty 2005). This, of course, may eventually change. Conservation training: the UK model At the time the author entered the London program (1969), a background in archaeology was considered desirable but could not be required. British students generally applied directly from secondary school, or after an extra year spent doing chemistry or studio art courses at a technical college; applicants with a university degree were at that time rare exceptions. Because of the differences in the educational systems, students from the US and Canada (and other countries with similar systems) were required to have an undergraduate degree. This degree, however, could be in any subject and was rarely in anthropology or archaeology, which at the time was not widely available as an undergraduate major.

In the area of field experience the programs differ widely in both preparation and supervision of students. Winterthur states that students going on digs are supervised (Norris 2005), but the qualifications of a supervisor do not seem to be clearly understood or standardized, nor is there any specific preparation for field work. In the past, from the author’s own knowledge, there has been no hesitation in sending a first-year student out to work with a second-year student whose only previous field experience was working with another student, none of whom had any previous field experience or background in archaeology. It seems probable that this has happened in the past with the other programs as well, though it is now extremely unlikely to occur at NYU or at Buffalo.

The answer for London was to include in the curriculum 2

The original proposal for this course (Severson 2002) called it a ‘field school’, which it certainly was not; the current term is ‘short course’ (NYU/IFA 2005b), a far more accurate description. 3 NYU/IFA is hoping to establish a similar relationship with the site of Abydos in Egypt (Adams 2005).

Buffalo students interested in archaeological conservation are ‘strongly urged’ to work on a dig, and they would be normally expected to work under an 29

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS the subjects that they felt to be essential, including archaeological method and theory, excavation experience, drawing, surveying, and field as well as studio photography. The narrow focus of the program allowed ample time for ‘background’ subjects. The three-year program also required first-year students to work several weeks in a museum during one of the vacations between terms, and two summers working as a conservator on a dig, almost always under the supervision of a more experienced conservator. Post-secondary school education in the UK has always been specialized, and that remains true today. Conservation training in the UK is now predominately on the graduate level,4 but all the programs, even those which lead to an undergraduate degree or diploma, are limited to study of a specific conservation specialty (UKIC 2003).

As far as curriculum is concerned, much of the necessary material is already in place, or could be easily incorporated, using adjunct or visiting faculty if necessary. Most of the deficiencies relate to training for field conservation. If prerequisites covered essential background, the primary addition would be structured preparation for field work similar to the short course at NYU, and a requirement that students interested in archaeological conservation spend adequate time in the field with proper supervision. There should certainly be an immediate end to the practice of sending any student who thinks archaeology sounds like fun out to work on an excavation. This is already less common than it used to be and should become entirely a thing of the past. The romance of archaeology belongs in the pages of newspapers and in fundraising brochures, not in graduate training programs in conservation.

Conservation training: the US model US programs traditionally have taken a different approach, with a first year spent exploring many areas of conservation and a second year devoted to more intensive work in a single area, which is continued in the third-year internship. This curriculum is consistent with the structure of university-level education in the US, with students taking a broad range of courses in the first two years, followed by concentration in a major field. This, however, is the model for undergraduate and not graduate education. Graduate students in all fields are expected to have narrowed their interests.

The future: some thoughts One unknown factor is the degree to which the new UCLA/Getty Program will affect the number of applicants to other programs who are interested in archaeological (or ethnographic) conservation. Many students may still prefer the broad first-year introduction to conservation. At least one conservator interviewed felt that students at specialized programs had a tremendous advantage over those trained in programs with an general introductory year (Koob 2005). However, the author, a graduate of a specialized program, believes that there is a great deal to be said for the US approach. Conservators with a broad background are more likely to be adaptable, and to be able to apply to their own area procedures and materials developed in other specialties. Competing with a specialized program, however, requires recognition of the nature of archaeological conservation and serious attention to both prerequisites and curriculum. Giving all objects majors an introduction to the problems of archaeological objects is an admirable goal, but it is not the same thing as training students to be archaeological conservators.

Without in any way altering the broad introduction given to first-year students, it would therefore not be unreasonable for conservation programs to add prerequisites, whether in academic background, craft skills and/or specialized training. In most cases this would only involve turning expectations into requirements, as was done for prospective furniture conservators at Winterthur. The programs have never had difficulty in setting prerequisites in chemistry. No one expects conservators to need all (or in the author’s experience, even most) of the material that they must master in the required courses, but it is essential that they are familiar with chemical equations and the molecular structure of matter before they can understand why materials deteriorate the way they do, what makes a soap different from a detergent, how to select an adhesive or a solvent, and what may happen if you use acid to clean a corroded metal object.

Winterthur is currently involved in establishing a minor in preventive conservation, pushed not only by student interest but recognition of the increased importance of the field. This minor will be available to students in any field (WUDPAC 2005b, c). The effort involved in formalizing the minor, and the care being taken to define the body of knowledge and the requirements for graduation, should offer a model for similar efforts in other special areas.

This is often described as ‘being able to speak the language’, and the same phrase was used by many of the conservators to describe the need for a knowledge of archaeology for a student interested in archaeological conservation.

This paper has concentrated on the issue of training conservators, but there are also parallel concerns in the training of archaeologists. Archaeologists who understand conservation already insist on proper credentials for conservators working on their excavations, and are in a position to educate their colleagues about the value of conservation and the

4 The list includes 16 programs with links to program websites. Eight are graduate level only (‘postgraduate’ in British terminology), three offer both undergraduate and graduate degrees or diplomas, and five offer only undergraduate level courses.

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VIRGINIA GREENE: TRAINING ARCHAEOLOGICAL CONSERVATORS New York University Institute of Fine Arts. E-mail to the author, 27 September 2005.

knowledge expected of a professional archaeological conservator. As conservators are putting increasing emphasis on establishing close ties with professionals in related fields, archaeologists are, in some places at least, being educated to see conservation as one of the many ancillary fields that may provide valuable assistance (Sharer 2005). It is to be hoped that all this will lead to more productive working relationships between archaeologists and archaeological conservators.

Norris, D.H. 2005. Personal communication. Chair and Associate Professor, Winterthur/University of Delaware Program in Art Conservation. E-mail to the author, 7 September 2005. NYU/IFA. 2005a. New York University Institute of Fine Arts Conservation Center. www.nyu.edu/gsas/ dept/fineart/conservation (accessed June 2009).

After AIC has concluded the process of defining specialized knowledge for areas of conservation, training programs may have to adjust both prerequisites and course content in order to ensure that graduates will be able to pass certification exams. If the AIC effort to establish certification for conservators leads to a new understanding of the nature of archaeological conservation, and to generally accepted standards for professional competence in this specialty, the process will have made a major contribution to the future of archaeological conservation in the US.

NYU/IFA. 2005b. Curriculum for a Short Course on Archaeological Field Conservation, 16–20 May 2005. New York University/Institute of Fine Arts Conservation Center. Unpublished document. O’Connor, D. 2005. Personal communication. Professor of Egyptian Art and Archaeology, Institute of Fine Arts, New York University. Co-director, Abydos Project. Interview with the author, 17 August 2005. Pearlstein, E. 2005. Personal communication. Academic Coordinator, UCLA/Getty Program in Archaeological and Ethnographic Conservation. E-mail to the author, 28 September 2005.

Acknowledgements The author is profoundly grateful to all those who agreed to talk about this subject, either in person or via e-mail. Any misrepresentation of opinions is inadvertent and regretted.

Peña, E. 2005. Personal communication. Director and Professor, Buffalo State College, Art Conservation Department. Interview with the author, 25 September 2005.

Bibliography Adams, M. 2005. Personal communication. Research Scholar, Abydos Project, NYU Institute of Fine Arts and University of Pennsylvania Museum. Interview with author, 17 August 2005.

Pouliot, B. 2005. Personal communication. Associate Objects Conservator, Winterthur Museum. E-mail to the author, 3 October 2005, 26 October 2005.

AIC. 2003. American Institute for Conservation. Defining the Conservator: Essential Competencies. http://www.conservation-us.org/_data/n_0001/ resources/live/definingcon.pdf (accessed June 2009).

Price, N.S. 1984. Excavation and conservation. In Conservation on Archaeological Excavations, ed. N. S. Price. Rome: ICCROM. Pye, E. 2001. Caring for the Past: Issues in Conservation for Archaeology and Museums. London: James & James.

Beaubien, H. 2005. Personal communication. Senior Objects Conservator, Smithsonian Center for Materials Research and Education. E-mail to the author, 16 September 2005.

Rose, C.B. 2005. Personal communication. Professor of Archaeology and Curator, Mediterranean Section, University of Pennsylvania Museum. Interview with the author, 12 September 2005.

BSC. 2005. Buffalo State College, Art Conservation Department. http://www.buffalostate.edu/depts/ artconservation (accessed June 2009). Cronyn, J.M. 1990. The Elements of Archaeological Conservation. London: Routledge.

Rose, C.L. 1975. A new approach to archaeological conservation. In Conservation in Archaeology and the Applied Arts, Preprints of the Contributions to the Stockhom Congress, 2–6 June 1975. London: International Institute for Conservation.

Grant, L.A. 2005. Personal communication. Conservator, University of Pennsylvania Museum. Interview with the author, 4 August 2005.

Sease, C. 2005. Personal communication. Senior Conservator, Peabody Museum of Natural History, New Haven. E-mail to the author, 16 August 2005.

Koob, S. 2005. Personal communication. Conservator, Corning Museum of Glass. E-mail to the author, 25 September 2005.

Severson, K. 2002. Proposal for a Field School in Archaeological Conservation. Modified by M. Marincola, 16 December 2002, 30 January 2003. New

Marincola, M. 2005. Personal communication. Chairman and Professor of Conservation, Conservation Center, 31

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS York University/Institute of Fine Arts Conservation Center. Unpublished document.

Address Virginia Greene Senior Conservator University of Pennsylvania Museum 3260 South Street Philadelphia, PA 19104 USA

Sharer, R. 2005. Personal communication. Professor, Department of Anthropology, University of Pennsylvania. Curator, American Section, University of Pennsylvania Museum. Interview with the author, 27 September 2005. UCLA/Getty. 2005. UCLA/Getty Program in Archaeological and Ethnographic Conservation. http://www.ioa.ucla.edu/conservation-program (accessed June 2009). UKIC. 2003. United Kingdom Institute for Conservation. Training in Conservation: A Brief Guide to Full-Time Courses in the United Kingdom. http://palimpsest.stanford.edu/ukic/training.html (accessed October 2005; link unavailable in June 2009, UKIC is at http://www.icon.org.uk). Wegner, J. 2005. Personal communication. Research Specialist, Egyptian Section, University of Pennsylvania Museum. Interview with the author, 15 August 2005. WUDPAC. 2005a. Winterthur/University of Delaware Program in Art Conservation. http://www.artcons.udel.edu (accessed June 2009). WUDPAC. 2005b. Winterthur/University of Delaware Program in Art Conservation. White Paper for Discussion on Preventive Conservation Education at WUDPAC. Unpublished document prepared by B. Pouliot and K. Kiefer. WUDPAC. 2005c. Preventive Conservation Issues Session, March 18, 2005. Winterthur/ University of Delaware Program in Art Conservation. Unpublished document. Zettler, R. 2005. Personal communication. Associate Professor, Department of Anthropology, University of Pennsylvania. Associate Curator, Near Eastern Section, University of Pennsylvania Museum. Interview with the author, 4 August 2005. Biography Virginia Greene holds degrees in anthropology from Barnard College and the University of Pennsylvania, and a Diploma in the conservation of archaeological and ethnographic materials from the Institute of Archaeology, University of London. She has headed the University Museum Conservation Laboratory since 1971. Ms. Greene has taught at the Winterthur/University of Delaware Conservation Training Program, and lectures widely to academic, professional, and community groups. She has extensive experience with a wide range of organic and inorganic materials, and field experience as both an archaeologist and a conservator.

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RESEARCH AND TRAINING IN A FIELD CONSERVATION LABORATORY: KAMAN-KALEHÖYÜK Glenn Wharton Abstract This paper describes the research and training program at the Kaman-Kalehöyük expedition in Turkey. The excavation is managed by The Middle Eastern Culture Center in Japan, a research institution based in Tokyo. Each year since 1986, an international team of excavators, researchers, and conservators convene to excavate and research the site during a four-month season. The institute is currently constructing a permanent facility that will house a museum, library, conservation laboratory, analytical laboratory, classroom, and living facility. The field conservation laboratory trains interns, teaches field conservation courses, holds symposia, and coordinates research and publications. Work in the conservation laboratory includes regular presentations to other staff members, training Turkish conservation students, and oversight of excavation and post-excavation processing of artifacts.

and field courses in archaeology, archaeobotany, and zooarchaeology.

conservation,

Sponsored by the Middle Eastern Culture Center in Japan (MECCJ), the Kaman-Kalehöyük expedition began in 1986. The site is located in central Turkey within the Kirşehir Province, on a branch of the ancient silk route approximately 100 kilometers southeast of Ankara. Like other mound sites in the region, KamanKalehöyük (Fig. 1) was settled in the Early Bronze Age during the 3rd millennium BC, and occupation levels continue into the Ottoman period of the 17th century AD. It was inhabited by each of the major Central Anatolian cultures of antiquity: Assyrian Trading Colony, Old Hittite Kingdom, Hittite Empire, Late Hittite, and Phrygian. The excavation goal is to clarify the regional stratigraphy for these occupation levels.

Introduction Training in archaeological conservation takes place on multiple scales, from university courses in materials science to experience with fragile artifacts at excavation sites. The knowledge required of an artifact conservator includes a theoretical understanding of soil chemistry, fabrication technologies, and mechanisms of deterioration. Skills include lifting methods, stabilization and reconstruction techniques, and archival storage strategies. The focus of this paper is research and training in artifact conservation as it occurs in the trench, the field laboratory, and the archaeological repository. Experience at an excavation is a critical element in a student’s training, even for artifact conservators whose careers ultimately lead to museum work. We learn from close observation during hands-on work. Understanding the concerns of archaeologists and other researchers at the site forces a realization that much of our knowledge of past cultures comes not just from the artifact, but also from the archaeological context. Associated soils, pollen, and other fine matter can be more informative than the artifact itself. Ian Hodder points to the process of archaeological interpretation at ‘the trowel’s edge’ (Hodder 1992: 92); similarly, conservators learn at the ‘tip of the swab’. Field experience teaches us about the subjective aspects of archaeology, and how much is lost at the moment an object is removed from its context. We learn that documentation and careful consideration is critical at every stage of an excavated object’s life.

Figure 1: The Kaman Kalehöyük excavation, Turkey. Photo: Middle Eastern Culture Center in Japan.

I was invited to join the excavation as staff conservator in 1991. My initial task was to establish a site laboratory and develop archival storage for the collections. By the end of this first season, the director described his vision of creating a permanent research facility at the site. He asked if I could create a field laboratory that would serve the needs of the site, while providing experience for students, offering courses, and promoting research and diffusion of information about archaeological conservation in Turkey. His enthusiasm was contagious. An insulated aluminum pre-fabricated building was erected for conservation during the 1993 season, which still serves as the field laboratory (Fig. 2). The permanent facility envisioned by Dr. Omura is currently under construction. The laboratory is now equipped with conservation tools and materials gradually purchased in Turkey, Japan, and the United States. It houses conservation staff during the excavation’s four-month season.

Archaeological field laboratories play an important role in training conservators by providing experience and research opportunities in the context of the excavation. Fortunately the director of the Kaman-Kalehöyük expedition realizes this. Dr. Sachihiro Omura’s future plans for the site include developing a full research facility that includes internships, research, publications,

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS spot testing, hardness testing, and specific gravity measurement.

Figure 2: The conservation laboratory at Kaman Kalehöyük. Photo: Middle Eastern Culture Center in Japan. Figure 3: Conservation staff and interns facing mud plaster paintings prior to lifting. Photo: Middle Eastern Culture Center in Japan.

Work in the conservation laboratory During the early years, I worked with Scott Carrlee, the Field Conservator, to establish the laboratory. We began structuring the work of the laboratory with a mission statement and staff descriptions. We developed an outline for what later became a set of notebooks containing treatment and collections management protocols for the rapidly growing artifact collection at the site. We identified key questions about the excavated materials, such as soil chemistry, soluble salt content of porous ceramics, and the stability of iron and copper alloy corrosion products. As we answered these questions over the succeeding years, we refined treatment protocols tailored to the specific circumstances of the site. Howard Wellman, the Field Conservator in 1999, compiled the treatment and collections management protocols into a set of three notebooks. Updated annually, these notebooks introduce new staff to the conservation methods employed at KamanKalehöyük. This growing body of knowledge within the laboratory allows staff to better understand the excavated artifacts and measure the success of conservation treatments. The collaborative approach to conservation at Kaman-Kalehöyük is detailed in a prior publication (Carroll and Wharton 1996).

Over the years that I directed the laboratory, my work shifted to organizing staffing, courses, symposia, and the research program. The Field Conservator managed the actual work in the laboratory. Eventually we developed an Assistant Conservator position for Serap Çelik, who performs conservation treatments, assists with the annual condition surveys, and oversees the Turkish conservation staff and student trainees. Elçin Bas, a local excavator, was trained in basic skills of ceramic desalination for repair. He became our Ceramics Conservation Technician, and works directly with archaeologists to select ceramics to repair for purposes of study and exhibition. Training and student research The internship program at Kaman-Kalehöyük includes student trainees from a high school level conservation program in Turkey, and internships for international students enrolled in undergraduate and graduate level conservation programs. Although the number of students varies each season, there are typically two student trainees and two interns in the laboratory over the course of the summer. The trainees stay approximately one month and the interns stay approximately six weeks at the site.

The excavation at Kaman-Kalehöyük is extremely active, and produces many hundreds of artifacts processed each season. As we established basic treatment methods, and the artifacts in storage grew to tens of thousands, our research expanded to include condition monitoring and archival housing.

The student trainee program was developed specifically for students from the Conservation Program at Başkent Vocational High School of Ankara University. In compliance with the requirements for their program, students conduct conservation treatments and participate in annual condition surveys under the direction of the Assistant Conservator. This training is typically in Turkish, although it includes entering treatment and survey data in English into the Treatment and Survey databases. To facilitate this, the Assistant Conservator translated all treatment protocols, directions for database use, and standard terms and phrases for condition assessment and treatment steps from English to Turkish.

Today the work of conservators at the site includes cleaning and stabilization of artifacts, archival housing, and annual condition surveys of the metal finds for retreatment. It also includes monitoring the storage environment and advising on environmental controls. The conservation staff assists the archaeologists in the field by excavating particularly fragile materials (Fig. 3). Each season the conservators provide basic training on field cleaning and lifting techniques for the excavators. The conservators also perform material identification through microscopy, X-ray fluorescence spectrometry,

The university level interns perform conservation treatments, participate in the condition surveys, give 34

GLENN WHARTON: RESEARCH AND TRAINING IN A FIELD CONSERVATION LABORATORY: KAMAN-KALEHÖYÜK presentations in the field and at site meetings, and perform a research project. The research projects help the conservation staff and researchers better understand the excavated materials and assist in developing laboratory protocols. Each year, I worked with the Field Conservator to generate a list of potential research projects for the following season’s interns.

Following the field aspect of their research projects, the interns develop a publishable manuscript. These papers are frequently published in Anatolian Archaeological Studies, MECCJ’s annual journal published in Tokyo. In addition to the formal research projects associated with internships, conservation staff pursues research to answer questions posed by archaeologists and visiting researchers. Some projects may simply be a matter of identifying excavated materials using microscopy, specific gravity measurement, or spot testing. Others become more involved, and at times lead to publication in the site journal. A list of research projects is included in Appendix A.

After interns were selected each year, they chose a research topic that met their research interests and benefited our work at the site. The interns developed research proposals, typically including a literature search, and completed preliminary laboratory analysis or a testing phase prior to coming to the site. The ‘field’ phase of the research typically involved testing a conservation procedure, analysis of artifacts, or measuring the effects of the storage environment on the collections in storage (Fig. 4).

Figure 5: Researcher Mei-An Tsu developing methods for conserving cuneiform tablets. Photo: Middle Eastern Culture Center in Japan.

Field courses After constructing the permanent facility, the expedition director plans to offer field courses every summer. The four branches of the institute (archaeology, conservation, zooarchaeology, and archaeobotany) will coordinate these rotating courses. The plan is to teach a conservation course every other summer. These one- or two-week intensive courses combine theory and practice, taking full advantage of the ongoing excavation, field laboratory, and field artifact storage. Three such courses were taught in prior years:

Figure 4: Intern Laramie Hickey-Friedman testing iron desalination methods. Photo: Middle Eastern Culture Center in Japan.

From the beginning, interns played a valuable role in helping us understand the condition of the materials excavated from the site. We deliberately designed research projects that helped us develop treatment and storage protocols. In 1993, research on excavated iron artifacts by Marie Svoboda helped us inaugurate an iron desalination project using extensive baths in alkaline sulfite solution. In 1994, intern Mei-An Tsu launched a low-fired ceramic investigation to establish protocols for desalinating our ceramic finds. She learned that most sherds excavated at the site have low soluble salt content, which led to a decision to only desalinate sherds prior to reconstruction. Other intern research projects helped establish methods for treating bronze disease, reassembling ceramics, removing painted wall fragments, consolidating unfired earthenware, stabilizing cuneiform tablets, treating lead objects, and controlling the micro- and macroenvironments in storage (Fig. 5).

Archaeological conservation in the field: A field school for archaeologists. 1995. Instructor: Claire Dean The aim of this two-week course was to introduce archaeologists to the practice of archaeological conservation and provide basic instruction in the care of archaeological materials in the field. Topics included the role of the conservator during excavation, establishing a field laboratory, materials science of excavated materials, documentation, lifting techniques, stabilization, packing, and storage. Formal lectures were combined with hands-on practice. Students lifted fragile materials, carried out basic cleaning operations, and created archival artifact housing.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS conservators and students attended the meeting. The sites represented at the symposium include Aphrodisias, Bozburun, Domuz Tepe, Gordion, Hacinebi Tepe, Kaman-Kalehöyük, Kazane Höyük, Kilise Tepe, Kinet Höyük, Sardis, Titris Höyük, and Uluburun. Participants of the symposium also included conservators from the Gordion Furniture Project at the Museum of Anatolian Civilizations in Ankara and the Conservation Training Program at Ankara University Başkent Meslek Yüksekokulu.

The conservation of archaeological ceramics: A field course for conservators. 1998. Instructor: Tony Sigel This course was taught through hands-on experience and informal discussions (Fig. 6). Students began by breaking pots purchased at a local market, and reconstructing them. They learned techniques of cleaning, desalinating, adhesion, gap filling, and inpainting on a combination of excavated sherds and modern pots. The unstructured nature of this course led to discussions that introduced the students to the theory and techniques involved in conserving archaeological ceramics in the field. Field course in bronze conservation. 1999. Instructor: Glenn Wharton Assistant Instructor: Howard Wellman Topics in this course included the examination and documentation of bronze artifacts, health and safety in the field laboratory, copper alloy corrosion, field analysis, conservation materials and techniques, treatment for bronze disease, exhibition, and storage. Students learned through a combination of formal lectures and hands-on experience with bronze artifacts excavated from the site.

Figure 7: Archaeological Conservation Symposium. KamanKalehöyük, June 27–29, 1997. Photo: Glenn Wharton.

An informal organization of conservators working in Turkey developed out of these symposia: Turkiye’deki Arkeolojik Konservatorler ile Archaelogical Conservators in Turkey (TAKIACT). Participants volunteered to work individually or in teams to pursue projects that evolved during the course of the discussions. The first joint project was a co-authored report documenting the conference discussions, published in May 1997. A second project was the development of a Web site. The TAKIACT site is now managed jointly by Jessica Johnson and Walter Henry, and hosted by Conservation OnLine: http://palimpsest.stanford.edu/byorg/takiact. The site provides links to a variety of helpful resources for conservation and preservation of archaeological materials excavated in Turkey.

Figure 6: Tony Sigel instructing field course on the conservation of archaeological ceramics. Photo: Glenn Wharton.

A third TAKIACT project was a series of guides on topics relating to archaeological conservation in Turkey. With support from the Edward Waldo Forbes Fund of the Freer Gallery of Art, Smithsonian Institution, MECCJ coordinated the publication of this series of twenty guides, titled Field Notes: Practical Guides for Archaeological Conservation and Site Preservation. The authors are all conservators and students who have worked in the field in Turkey. A complete list of the Field Notes is presented in Appendix B. They are available for downloading on the TAKIACT Web site.

Professional collaboration Another aspect of the work at Kaman-Kalehöyük is fostering communication between professional conservators working in the field and in museum repositories in Turkey. Several projects were conducted to pursue this aspect of the laboratory’s mission, with more planned after establishing the permanent facility. Two symposia held during the 1996 and 1997 seasons included archaeological conservators who work in Turkey (Fig. 7). The goal of these symposia was to initiate communication between conservators, students, and others interested in advancing the field of archaeological conservation in Turkey.

The Field Notes series is intended for archaeologists, conservators, and students. They are to be used as resource guides for the stabilization and preservation of excavated materials and archaeological sites. The texts are printed in English and Turkish, and are illustrated

The aim of the first symposium was to provide a forum for participants to discuss their work and consider the state of archaeological conservation in Turkey. Twelve 36

GLENN WHARTON: RESEARCH AND TRAINING IN A FIELD CONSERVATION LABORATORY: KAMAN-KALEHÖYÜK with photographs from archaeological excavations and educational institutions in Turkey.

Address Glenn Wharton Museum Studies/Conservation Center of the Institute of Fine Arts New York University 240 Greene St. Suite 406 New York, NY 10003 USA

Conclusion Due to a change in my employment in the US, 2004 was my last season as Conservation Director at the KamanKalehöyük expedition. I left during an exciting period of change, as the permanent laboratory and research facility was being constructed. The conservation staff is now charged with planning for a new museum along with all of their other responsibilities. I look forward to watching the development of the facility, and hope that our initial efforts in establishing a research and training program for the site serve as a foundation for future programs. Acknowledgements A flood of memories and faces come to mind when I reflect on my tenure as Conservation Director at KamanKalehöyük. I thank all of the Field Conservators, staff, and interns who worked in the laboratory over thirteen seasons. Our accomplishments were a team effort—with a constantly revolving team of players. The momentum we gathered is a direct result of the vision shared by Dr. Omura, Prince Mikasa, Masako Omura, Kimiyoshi Matsumura, and the staff of the Middle Eastern Culture Center in Japan. I thank them all for giving me this lifechanging experience. I hold high hopes for the future of Kaman-Kalehöyük, as the permanent facility is constructed and new research and educational projects develop in the future. Bibliography Carroll, S.. and G. Wharton. 1996. Field conservation at Kaman-Kalehöyük: a holistic approach. In Archaeological Conservation and Its Consequences, eds. A. Roy and P. Smith, 22-26. London: International Institute for Conservation. Hodder, I. 1999. The Archaeological Process. Oxford: Blackwell Publishers. Biography Dr. Wharton is on faculty at New York University, with a joint appointment at the Institute of Fine Arts Conservation Center and the Museum Studies program in the Faculty of Arts and Science. He received his MA in conservation from the Cooperstown Graduate Program in 1981 and a PhD from the Institute of Archaeology, University College London in 2005.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Appendix A: Conservation Research Projects at Kaman-Kalehöyük, 1993–2004 DATE 1993 1993 1992-1993 1993 1994 1994-1995

TITLE Desalination of Iron Artifacts Ink Light Sensitivity Tests Analysis of Potential Ceramic Mending Adhesives by FTIR Methods Ceramic Mending Tests Desalination of Low-fired Ceramics Mud Plaster Facing Adhesive Tests

1995 1995

Technical Study of a Painted Wall at Kaman-Kalehöyük Wall Painting Conservation Research Report

1995 1995 1995

Preliminary Technical Investigation into Iron Age Ceramics Consolidation of Mud Brick Loom Weights Scientific Analysis of Seven Bronze Artifacts from KamanKalehöyük Scientific Analysis of Plasters (pit lining material, mud plaster painting, excavated plaster) Identification of Green Post-Burial Deposition on Ceramics Fill Materials for Ceramics Plasticine Tests Tests for Readhering Labels in Storage

1995

1995 1996 1996 19961997 1997Cuneiform Tablet Research 1999 1997, 1998, Oddy Tests: Samples of Conservation Materials Used in the Lab 1999 1997 Conductivity Profile of Soil

RESEARCHER(S) Marie Svoboda Glenn Wharton John Twilley Glenn Wharton C. Mei-An Tsu Glenn Wharton Marie Svoboda C. Mei-An Tsu Glenn Wharton, C. Mei-An Tsu, Marie Svoboda, Scott Carroll, Kendra Roth C. Mei-An Tsu Kendra Roth John Twilley John Twilley Marie Svoboda Hiroko Kariya Hiroko Kariya Hiroko Kariya C. Mei-An Tsu Various conservators Scott Carroll (Kaman), Jessica Johnson (Gordion), Donna Strahan (Troy) Nicola Smith Claire Peachey, Evren Çolak Claire Peachey Tony Sigel Joanne Boyer Glenn Wharton, Claire Peachey, Joanne Boyer, Evren Çolak, Gokhan Ayik

1997 1998 1998 1998 1998 1998

Use of BTA Within Wax Coatings Consolidation and Lifting of Carbonized Organic Material Consolidation and Excavation of 12 Unfired Clay Loom Weights Ceramic Reconstruction Ceramic Fabrication Painted Mud Plaster Treatment Considerations

19992001 1999 1999-2000 1999-2001 1999-2000 1999-2000 2001

Storage of Iron Using RP System

Laramie Hickey-Friedman

Technical Research: Carbonized Fiber Object Iron Treatment and Storage Corrosion Inhibitors for Copper Alloy Artifacts Adhesive Strength and Aging Testing of Tapes for Supporting Ceramic Sherds Copper Alloy Corrosion Analysis

Joel Thompson Laramie Hickey-Friedman Stavroula Golfomitsou Sara Moy Sara Moy John Merkel, Stavroula Golfomitsou Martin Ledergerber David Graves Margaret Kipling Claudia Chemello

2001 2002 2003 2003 2004

Conservation of Lead at Kaman-Kalehöyük Metal Storage using Cryovac Film and Artsorb Sheet Preventive Conservation at Kaman-Kalehöyük Conservation of Excavated Iron Objects from the Archaeological Site of Kaman-Kalehöyük Turkey: A Closer Look Biodegradation of Microcrystalline Waxes

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Nina Zaitseva

GLENN WHARTON: RESEARCH AND TRAINING IN A FIELD CONSERVATION LABORATORY: KAMAN-KALEHÖYÜK Appendix B: A list of co-authored Field Notes: Practical Guides for Archaeological Conservation and Site Preservation. Sponsored by the Edward Waldo Forbes Fund of the Freer Gallery of Art, Smithsonian Institution, and the Middle Eastern Culture Center in Japan. Available for downloading at http://palimpsest.stanford.edu/byorg/takiact. FIELD NOTES: PRACTICAL GUIDES FOR ARCHAEOLOGICAL CONSERVATION AND SITE PRESERVATION 1.

The Role of the Conservator on an Archaeological Excavation: Catherine Sease

2.

Guidelines for Foreign Conservators Working in Turkey: Hande Kökten-Ersoy

3.

Conservation and Related Materials: Supplies and Shopping in Turkey: Kent Severson

4.

Selected Bibliography - Conservation in the Field: Krysia Spirydowicz

5.

Legislation for the Protection of Cultural and Natural Property of Turkey: Hande Kökten-Ersoy

6.

Health and Safety in the Field Laboratory: Tania Collas, Scott Carroll

7.

Educational Opportunities for Turkish Conservators: Hande Kökten-Ersoy

8.

Documentation of On-Site Conservation Activities: Ellen Salzman, Claire Peachey

9.

On-Site Storage of Excavated Materials: Hiroko Kariya, Claire Peachey

10.

Archaeological Site Protection in Turkey: Kent Severson

11.

Conservation of Metal Artifacts: Glenn Wharton, Hande Kökten-Ersoy

12.

Conservation of Ceramic Artifacts: Donna Strahan, Julie Unruh

13.

Conservation of Stone Artifacts: Hiroko Kariya, Axel Nielsen

14.

Conservation of Unfired Earthen Artifacts: Kendra Roth, Mei-An Tsu

15.

Conservation of Excavated Wood and Plant Materials: Krysia Spirydowicz

16.

Conservation of Excavated Textile and Leather: Latif Özen, Krysia Spirydowicz

17.

Conservation of Excavated Ivory, Bone, and Antler: Latif Özen, Krysia Spirydowicz

18.

Conservation of Mosaics in the Field: Kent Severson, Hande Kökten-Ersoy

19.

Conservation of Wall Paintings in the Field: Kent Severson

20.

Conservation of Marine Finds: Kathy Hall, Asaf Oron, Tuba Ekmekci

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ARCHAEOLOGICAL CONSERVATION IN THE U.S. NAVY Claire Peachey Abstract The U.S. Navy is the steward of significant archaeological resources, both on land and under water, which it protects through compliance with federal standards and regulations. Conservation of archaeological materials receives varying levels of funding and attention. A clear difference exists between underwater and terrestrial materials. Specific funding has been allocated for conservation of shipwreck artifacts and sites, while conservation of terrestrial archaeological materials tends to be considered part of overall archaeological processing, collections management, and curation activities. The Navy faces the same curation issues that other US federal agencies face: inadequate curation conditions of older collections, and diminishing space and increasing costs for curation of new materials. Additional pressures are imposed by the competing missions of military readiness and resource preservation. By forging partnerships with curation facilities, universities, conservation laboratories, educators, and others, the Navy provides for conservation, interpretation, and access of its archaeological assets.

Underwater archaeology The Navy has done considerable work toward the preservation and conservation of underwater archaeological resources. The recent passage of the Sunken Military Craft Act has been a significant contribution. This act articulates the long-standing interpretation of the property clause of Article IV of the United States Constitution, and of international maritime law, that the U.S. Navy holds perpetual title to all its sunken ships and sunken aircraft, no matter where in the world they are located, and no matter how much time has passed since their sinking. It specifies that Navy shipwrecks and aircraft wrecks belong to the Navy (unless they have been formally abandoned), and that it is illegal to disturb or take anything off of those wrecks without permission from the Navy. The Act was signed into law by President George W. Bush in October, 2004, as part of the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (Public Law 108375, Div. A, Title XIV, Sections 1401 to 1408, Oct. 28, 2004, 118 Stat. 2094). For Navy shipwrecks and aircraft wrecks older than 50 years old, the department responsible for managing and protecting those resources is the Underwater Archaeology Branch of the Naval Historical Center (NHC), located in Washington, DC. Conservation has been a significant part of this department’s activities since it was established in 1991. One of the events that led to establishing the department was the discovery of the wreck of the Civil War commerce raider CSS Alabama (1864) off the coast of France in 1984; an agreement drawn up between the United States and France established joint management responsibilities for this wreck site, including excavation and conservation of artifacts. A significant portion of the agreement dealt with artifact conservation responsibilities, from the field to the laboratory.

Introduction The Department of the Navy is a large-scale owner of historic buildings, structures, districts, archeological sites and artifacts, ships, aircraft and other cultural resources. Protection of these components of the nation’s heritage is an essential part of the defense mission; the Department of the Navy is committed to responsible cultural resources stewardship. (SECNAVINST 4000.35A, April 2001, Department of the Navy Cultural Resources Program.) The U.S. Navy is the custodian of significant archaeological resources, both on land and under water: it owns approximately 3 million acres of land, and is responsible for all its sunken ships and aircraft wrecks. Under the National Historic Preservation Act (NHPA), the Navy, as a federal agency, is obligated to protect its historic properties, including archaeological resources. Section 110(c) of the NHPA mandates that each federal agency operate a historic preservation program, and designate a qualified federal preservation officer to run it. The Navy’s Federal Preservation Officer is the Deputy Assistant Secretary of the Navy (Environment).

Since 2000, the Underwater Archaeology Branch has had a permitting process for allowing archaeological activities on the Navy’s historic ship and aircraft wrecks. The permit application guidelines are published in the Federal Register: 32 CFR 4 Part 767, Application Guidelines for Archeological Research Permits on Ship and Aircraft Wrecks Under the Jurisdiction of the Department of the Navy. The permit application does not require a conservation plan, or that a conservation facility be named, but it does require a curation facility to be named, and that facility must meet the standards set forth in 36 CFR 79, Curation of Federally Owned and Administered Archeological Collections. In addition, the guidelines state that if materials are recovered from a site, the final report to the Navy must include descriptions and photographs of the conserved artifacts, and laboratory conservation records. The entity performing the archaeological work is responsible for the conservation.

Archaeological excavation carried out on many of the Navy’s properties results in large collections of artifacts and associated documentation. This paper explores the different ways that the Navy accomplishes conservation of its archaeological collections. The discussion is divided into underwater archaeology and terrestrial archaeology, as there are differences in how the Navy incorporates conservation into each of these sub-fields. 41

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS The Navy was fortunate in that it received major funding for underwater archaeology and conservation projects from the Department of Defense Legacy Resource Management Program (known as “Legacy”). This program funds both cultural and natural resource management projects. Many Legacy grants were administered through the NHC Underwater Archaeology Branch, and for shipwreck projects that involved excavation of artifacts, conservation was a distinct section of a project’s budget; in some instances, an entire grant was awarded for artifact conservation. The Legacy program encourages partnerships, so many of the projects have been jointly funded and carried out with other federal, state, and private agencies and institutions.

and materials science input is often important for developing these in situ plans and for monitoring their success. Terrestrial archaeology Conservation for Navy terrestrial archaeology is not so clearly defined. A discussion of conservation of terrestrial materials is really a broader discussion of collections management and cultural resource management. This seems to be common to terrestrial archaeology in general in the United States, where there has not always been a strong tradition of specifically incorporating conservation into planning, budgeting, and research designs. There is not a central permitting office for Navy terrestrial archaeology. The Commanding Officer of each Navy installation is responsible for complying with the federal historic preservation regulations as they apply to the base. Each installation is required to appoint a cultural resources manager who is to be consulted when activities will impact cultural resources on the base. That person may be someone whose primary duties or expertise are in another field, such as natural resources or engineering, so the Navy provides regular training on compliance issues, to enable the cultural resources manager to carry out preservation responsibilities. Navy policy for cultural resources management is found in OPNAVINST 5090.1B, Environmental and Natural Resource Program Manual, Chapter 23, Cultural Resources Management (October 2002).

Some of the Legacy- and Navy-funded projects related to conservation of underwater archaeological resources include: • Treatment of hundreds of artifacts from the CSS Alabama (1864) wreck site at five different conservation laboratories. • Establishment of a conservation laboratory and a conservator position at the Naval Historical Center. • Excavation and conservation of the Civil War submarine H.L. Hunley (1864), including the development of conservation research partnerships between government, academic, and private entities. • Conservation of artifacts from Revolutionary War sites in Lake Champlain, and from wrecks of the Penobscot Expedition of 1779. • Conservation of artifacts plundered from the Civil War shipwrecks CSS Florida (1864) and USS Cumberland (1862). • Publication of a manual of conservation of artifacts from underwater sites (Hamilton 1996). • Promotion of the study of conservation of aircraft raised from underwater sites. • Development of a preservation and management plan for an intact Revolutionary War gunboat in Lake Champlain. • Long-term preservation and management strategies for the WWII wreck of USS Arizona (1941), including collecting corrosion data and conducting material analyses. • A study of the effect of zebra mussels on the condition of shipwrecks in Lake Champlain.

Archaeological work on bases is usually initiated when there is going to be any kind of ground disturbance, such as new construction, road improvements, or some types of military training. Archaeological work may also be conducted as part of the installation’s development of an Integrated Cultural Resource Management Plan (ICRMP). This plan requires inventory and evaluation of installation cultural resources, so that conflicts can be avoided between Navy mission needs and preservation considerations. This is an important proactive management and planning strategy that results in preservation of sites through non-disturbance. If archaeological work needs to be carried out, the work is usually put out to bid and awarded to an independent archaeological contractor. When the work is completed, the contractor provides a report, original documentation, and any excavated materials, all packaged according to the specific requirements of the Navy facility or the final curation facility, as specified in the scope of work of the contract. Archaeological work might also be undertaken by the archaeology or anthropology department of a nearby university, where the material is often then housed and studied. All collections are required to be curated according the standards in 36 CFR 79, although this has not always happened. Boxes of material may await curation in someone’s office, for example—the well-known phenomenon of long-term temporary storage.

The attention given to conservation in these Navy archaeological projects arises largely from the unstable nature of the material. There is a clear need for conservation of materials excavated from underwater environments, so a clear need to budget for it. It has long been recognized that underwater archaeology and conservation are intertwined, and that conservation can be time-consuming and expensive, but is essential for interpretation and preservation of the materials. Some of the projects in the above list are studies leading to in situ management plans for underwater sites. In situ preservation is a preferred, or even necessary, option for many underwater archaeological sites, and conservation 42

CLAIRE PEACHEY: ARCHAEOLOGICAL CONSERVATION IN THE U.S. NAVY and many of the polyethylene zip-lock bags needed to be replaced because of tears or increasing brittleness caused by storage in environments without proper climate control. Associated records were not stored in acid-free housings and incorporated contaminants such as paper clips, staples, and rubber bands (Anderson et al. 2000: xxi, xxv).

Many times, material excavated from these undertakings does not require active conservation, or is not perceived to require it. Preventive conservation through proper processing and packaging is all that is needed. If active conservation is needed, it is generally not funded as a separate, budgeted item; it is part of the overall budget for excavation and curation, and can be accomplished in a variety of ways. For example, • for work done by an archaeological contractor, conservation may be written into the scope of work of the contract as laboratory analysis of materials; • a university department or private institution may perform conservation as part of a research partnership, with no cost to the Navy; • a cultural resources manager may use limited discretionary funds for special analyses or for treatment of an unexpected find; • a manager may have an informal agreement with a local conservation lab to do some treatments; • or a curation facility may do it as part of periodic collections maintenance, included in annual curation fees.

In addition, human remains were not all inventoried and reported to comply with NAGPRA, the Native American Graves Protection and Repatriation Act (25 U.S.C. 2001 et seq.) of 1990. This act mandates that federal agencies identify their holdings of Native American human remains, funerary objects, sacred objects, and objects of cultural patrimony, and consult with Native American groups regarding the disposition of those materials. The problems with DoD’s archaeological collections are well stated in the introduction to one of these reports: Federal archaeological collections are a nonrenewable national resource, a legacy to the prehistoric and historic events that have shaped the nation. The American public is the owner of these materials and documentation, and as such it is incumbent upon the Department of Defense (DoD) to uphold the laws and regulations set forth by Congress for their proper use and care in perpetuity. Unfortunately, for the last 50 or more years, curation of these materials has been insufficient and/or ignored. Many collections have been lost or destroyed, and many have been damaged. They are often not stored in repositories equipped and staffed for the purpose of archaeological curation, but instead are stored n closets, basements, storage sheds; very few repositories meet the requirements outlined in 36 CFR Part 79, Curation of Federally-Owned and Administered Archaeological Collections (1991). The improper care and subsequent deterioration of many of these collections not only violates the laws under which they were recorded but also prevents educational and scientific use. Valuable portions of our irreplaceable national heritage have been lost, and our financial investment in archaeological recovery has been often compromised. (Anderson et al. 2000: xix)

Many times, the attention paid to conservation may depend on the priorities of the individual responsible for the base’s cultural resources management program, and the strength of that program. For example, bases with extensive and nationally important archaeological and historical resources may have more well-developed programs and cost-sharing partnerships. In these arrangements, conservation may get performed by archaeologists, laboratory technicians, collections managers, curators, students, conservators, or not at all, and the extent and quality of conservation treatment may vary. There are examples of funding being directed specifically toward conservation of Navy terrestrial archaeological collections, within a curation context. In 1992, the DoD Legacy Resource Management Program began providing funds to the U.S. Army Corps of Engineers St. Louis District to inventory archaeological collections recovered from DoD installations (not just Navy), and to assess the curation facilities in which they were held. In 1994, the Army Corps of Engineers created the Mandatory Center of Expertise for the Curation and Management of Archaeological Collections (MCXCMAC) in St. Louis, charged with assisting federal, state and local agencies in archaeological collections management, among other activities. The results of this group’s surveys of DoD collections are published in a series of reports available to the public.

This problem is not unique to Department of Defense collections, but is mirrored in U.S. federal archaeology collections in general. It is part of the general “crisis” in collections, leading to a call for increased awareness of long-term curation responsibilities, the establishment of curation fees in facilities that comply with 36 CFR 79, and the need for deaccessioning policies and new field collection and sampling policies (e.g., Childs 1995).

The MCX-CMAC surveys found that a large portion of DoD’s collections were not stored in ideal conditions. For example, in one survey of eastern states, only 16 of 132 repositories examined complied with 36 CFR 79. Aside from overall environmental problems with buildings, artifacts were stored in acidic boxes and bags, boxes were overpacked, artifacts were loose in boxes,

After these surveys, the Navy prioritized their improperly maintained collections based on condition, importance, and size of collection, among other factors, and estimated the cost of remedying their conditions. When budgeting in 2001, a cost of $500/cu ft was 43

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS almost certainly include field collection guidelines and deaccessioning instructions, as these are considered important and necessary strategies for easing the curation burden without compromising archaeological information.

estimated for rehousing and stabilization of the collections (Munsell 2001: 3), a process referred to as “rehabilitation.” With the help of DoD Legacy and other sources of funding, some of the materials were fully inventoried, processed, rehoused, and stored in appropriate curation facilities. This work included some active conservation treatments to stabilize deteriorating materials. Not all the collections have received attention, and some may not be considered action priorities.

A few case studies illustrate some of the approaches the Navy has taken to terrestrial archaeological preservation, and by extension, conservation. • Naval Air Station Pensacola, Florida. This collection is considered a priority because it is the “the Navy’s largest single concentration of archaeological collections, and much of it is in very poor condition” (Munsell 2001, p. 4). It consists of over 2000 cu ft of excavated materials, in addition to the associated records. Much of the collection has never been washed or labeled. The installation is working incrementally toward the goal of creating a curation facility on base. After Hurricane Ivan in 2004, which did a great deal of damage in the area, the installation received funding to repair the present non-compliant storage facility, and has put in a budget request for future funding to upgrade the building. In order to begin the work soon, rather than wait for future budget allocations, the installation is using discretionary funds to hire an archaeological contractor to begin to process and rehouse the collections. This work will be done on base in climate-controlled mobile storage areas. Any conservation treatments are likely to be carried out by the archaeological contractor. The rehabilitation of this collection may be completed before a permanent curation facility is available. • Naval Air Weapons Station China Lake, California. This 1.1-million acre base is home to the Coso Rock National Historic Landmark, a huge area of prehistoric and historic rock art and archaeological sites. Despite limited funding, the installation’s engineers and archaeologist have converted an old ice house on the base into a curation facility, and are working toward full compliance with 36 CFR 79. The base’s program has developed a strong connection with the local community, which has a volunteer network that helps to process the collections. There are hopes to partner with a private conservation institution to document deteriorating rock art on the base, as a move toward getting it conserved. National Historic Landmark status may lead to greater recognition of the resource, and translate into more funding. • Naval Air Station Patuxent River (known as Pax River), Maryland. This base has more than 160 identified archaeological sites, as well as significant historic buildings and natural resources. The base has had cooperative agreements with the Maryland Historical Trust since the 1980s, and now has a curation agreement with the nearby Maryland Archaeological Conservation Laboratory, a state curation and conservation facility with a full-time staff of conservators. The curation agreement included an initial condition assessment of the existing collection, and the installation provides

The Navy has also established budgeting mechanisms for requesting funds for curation expenses, and this falls under environmental planning and management. In the annual budgeting process for environmental compliance (EPR, environmental program requirements), there are line items that allow for non-recurring curation expenses such as preparation for long-term storage, and for recurring curation expenses such as annual fees for maintenance. This funding is not always approved, and there are some kinks in some of the Navy’s curation agreements. Also, our involvement in the wars in Afghanistan and Iraq has resulted in some loss of environmental and cultural resources funding, and has also increased pressure to prioritize military readiness over preservation. Accelerated training requirements and the closing of bases means there are fewer places to train, and therefore more potential for resource disturbances. Another valuable outcome of the work of the MCXMCAC was the Legacy-funded publication in 1999 of “Guidelines for the Field Collection of Archaeological Materials and Standard Operating Procedures for Curating Department of Defense Archaeological Collections” (Griset and Kodack 1999). This 161-page volume contains a large section entitled “Conservation Criteria for Archaeological Materials,” which includes preventive conservation, materials deterioration, and general approaches to conservation treatments. It does not provide instructions for treatments, and notes that conservation treatments “should be performed by, or under the supervision of, a trained professional conservator” (Griset and Kodack 1999: 72). It does include instructions for procedures such as cleaning and labeling, in the section “Processing Artifacts and Samples,” and has a large section on curation of archaeological documentation. The office of the Navy’s Federal Preservation Officer is in the process of developing a Collections Management Policy for the Navy, and perhaps for all of the Department of Defense, that will likely be modeled on these published guidelines, and will include much conservation-related information. It is not clear to what extent specific standards and qualifications for conservation will be mandated, however; there are varying levels of interest in codifying conservation requirements in any regulations. Two opposing views are that a) regulations are necessary in order to get needed conservation done and to justify the expense to leadership, and b) that it is already hard enough to get compliance with 36 CFR 79 without adding further requirements. The collections management policy will 44

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additional funding for treatment of prioritized items as it can. NAS Patuxent River encourages community involvement and has received numerous awards for its stewardship activities, including being recognized by the Secretary of the Navy in 2000 as the Navy's leader in historic preservation. Naval Air Station North Island, San Clemente Island, California. This is the southernmost of the Channel Islands off the coast of California, with high-density, well-preserved archaeological remains. The cultural resources program there involves longstanding research partnerships with several universities, museums, state facilities, and local groups, including University of California Los Angeles, California State University Northridge, the Natural History Museum of Los Angeles County, and San Diego Museum of Man, to name a few. The program includes archaeological field schools, ongoing research on the excavated collections, storage at professional curation facilities, and conservation by professional conservators and collections managers with conservation expertise. Legacy provided funding for the uniform packaging and standard cataloguing of the installation’s collections, resulting in increased access for researchers and other users.

Childs, S. T. 1995. The Curation Crisis. Common Ground 7(4): 11-15. Griset, S., and M. Kodack. 1999. Guidelines for the Field Collection of Archaeological Materials and Standard Operating Procedures for Curating Department of Defense Archaeological Collections. Legacy Project No. 98-1714. U.S. Army Corps of Engineers, St. Louis District, Mandatory Center of Expertise for the Curation and Management of Archaeological Collections. Hamilton, D. L. 1996. Basic Methods of Conserving Underwater Archaeological Material Culture. U.S. Department of Defense Legacy Resource Management Program, Washington, DC. Munsell, E. L. 2001. Status of the U.S. Navy’s Archaeological Collections Long-Term Curation Strategy. Report to DUSD(ES)/EQ-CO, February, 2001. Acknowledgements I would like to thank the many Navy archaeologists who spent time explaining their programs to me. Any errors in the paper are entirely my own. Biography Claire Peachey is an editor for the Navy. Previously she was a conservator in the Underwater Archaeology Branch of the Naval Historical Center, where she works on waterlogged archaeological artifacts and historical maritime objects. She has a combined education and career in terrestrial and underwater archaeology (MA Anthropology/Nautical Archaeology, Texas A&M University) and archaeological conservation (University College London).

Three of these examples feature significant public involvement in their programs, which can be an important benefit. This kind of attention helps to convince military leadership, who are balancing so many competing needs, that a high standard of cultural resource stewardship is worth maintaining. The Navy has the same collections management and conservation issues as other federal agencies that collect and curate archaeological collections. Spurred by federal legislation, the Navy has created standards for cultural resource preservation, and appointed staff to perform the required compliance duties. Through Department of Defense and other funding, the Navy promotes and conducts conservation of excavated underwater material, is inventorying and rehabilitating existing terrestrial collections, and has created budgeting mechanisms for professional curation. For terrestrial collections in particular, conservation is tied directly into resource management and collections curation, and not always considered as a separate need. Much work remains to be done, and the Navy system has its impediments, but many Navy installations prioritize archaeological resource management, and partner with other stakeholders to preserve and provide access to the public resources for which they are responsible.

Address Naval Research Laboratory 4555 Overlook Avenue, SW Washington, DC 20374

References Anderson, L., et al. 2000. An Archaeological CurationNeeds Assessment of Military Installations in Selected Eastern States. Technical Report No. 23. 2 vols. Legacy Project No. 97-1615. U.S. Army Corps of Engineers, St. Louis District, Mandatory Center of Expertise for the Curation and Management of Archaeological Collections. 45

GETTING THE JOB DONE: CHALLENGES PRESENTED BY CONTINUITY, CHANGE, AND CONTROVERSY IN THE CONSERVATION OF ARTIFACTS IN SHIPWRECK ARCHAEOLOGY Sarah Watkins-Kenney Abstract This paper examines the themes of continuity, change, and controversy presented during the conservation of artifacts recovered in underwater shipwreck archaeology, with particular reference to North Carolina. Conservation of artifacts from the Beaufort Inlet Shipwreck, believed to be the Queen Anne’s Revenge, the flagship of the pirate Blackbeard, provides the main case study for the integration of archaeological conservation in underwater archaeology. Issues discussed include: resources; conservation practice; and the attitudes and expectations of the public and professionals. Finally, conservators are part of a dynamic archaeological process and the nature, extent, and success of practical application will depend on how conservators manage continuity, change, and controversy within the context of archaeology.

partnership between NCUAB, Intersal Inc., its non-profit Maritime Research Institute, the North Carolina Maritime Museum, and specialists and experts from various institutions and organizations, including East Carolina University (ECU). The wreck is one of the oldest on the Atlantic coast of North America that is available for study, and thus offers a rare opportunity for the archaeological study of a critical period in colonial America. Investigations to record and assess the site included some limited excavation between 1997 and 2000 and again in 2005 (Lusardi 2000; Lawrence and Wilde-Ramsing 2001; Wilde-Ramsing 2005). Some 20,000 items, including 8 cannon, have been retrieved, but it is estimated that this represents a mere 5% of the site. Even so, the artifact assemblage reflects a broad range of early 18th-century maritime culture. Ships parts and equipment, arms, scientific, navigational, and medical instruments, personal effects, and food preparation and storage items have been recovered. Studying the artifacts helps archaeologists and historians gain valuable insights into the period’s naval technology, colonial provisioning, shipboard life, and potentially the material culture of piracy. Before they can be studied, however, the artifacts have to be conserved. Since the beginning of the project, the team has included a conservator.

Introduction North Carolina has a rich maritime history. This state on the Atlantic seaboard of the United States has some 300 miles of ocean shoreline, coastal sounds equivalent to a ‘vast inland sea’ (Lawrence 2003) and thousands of miles of navigable rivers and creeks. There are more than 5000 historic shipwrecks in its waters (Babits 2002:119), testimony to the treachery of shifting shallows over sandbanks; storms and hurricanes; and war. Of particular significance, affecting commercial and political development in North Carolina, was the pirate terror along the Atlantic coast in the early 18th century. In the summer of 1781, after months of pirating in the Caribbean and off the Carolinas, Blackbeard, the archetypical pirate, lost his flagship, Queen Anne’s Revenge, off Beaufort, North Carolina (Lee 1995; Moore 1997).

This paper discusses the conservation of artifacts from the wreck in a context of continuity, change, and controversy in relation to underwater shipwreck archaeology in North Carolina. It is not a discussion of treatment methods but rather a case study of the integration of archaeological conservation in underwater archaeology. Keith (2002), in discussing preservation in underwater archaeology, writes, ‘Perhaps the principal difference between a “good” project and a “bad” project is the extent to which attention is paid to preservation.’

Divers from Intersal Inc., under the direction of Phil Masters and Mike Daniel, discovered an early 18thcentury shipwreck in 24 feet of water about a mile and a half off Beaufort in November 1996. They were searching for the Queen Anne’s Revenge (QAR) under a permit issued through the North Carolina Underwater Archaeology Branch (NCUAB). Being within 3 miles of the North Carolina coast, the wreck, called the Beaufort Inlet Shipwreck, fell under the jurisdiction of the State (NC 1967). It was designated a protected area in March 1997 by the North Carolina Department of Cultural Resources (NCDCR 1997) and listed on the National Register of Historic Places in 2004.

Underwater archaeology and archaeological conservation in North Carolina: a brief history The invention of the aqualung in 1942 by Jacques Cousteau and his colleagues (Grant 1990:20) led very quickly to the exploration of wrecks all over the world by sport divers, treasure hunters, and archaeologists. In North Carolina the Civil War wrecks in the Cape Fear area attracted particular attention (Watts 1985). In 1962–1963, Navy divers working under the direction and supervision of the North Carolina State Office of Archives and History (NCA&H) recovered several thousand artifacts from the Modern Greece (1862) and other Civil War wrecks in the Cape Fear area (Watts and Bright 1973). In 1963, the volume of finds recovered prompted an Act of the North Carolina Legislature

In 1997, one of the NCUAB permanent staff archaeologists, Mark Wilde-Ramsing, was assigned to lead a team to investigate, preserve, and manage the Beaufort Inlet Shipwreck (site number 31CR314, previously numbered NC 0003BUI). The project, named the Queen Anne’s Revenge Shipwreck Project, is a 47

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enabling the establishment of a permanent preservation laboratory administered by NCA&H. The 1963 Act provided a budget for staff (a ‘Preservationist’, an ‘Assistant Preservationist’, and part-time laboratory assistants) and for operating and improving the lab facility at Fort Fisher Historic Site near Wilmington, North Carolina. By 1965 there was a 4200 cubic ft store room for untreated materials, a study collection room with controlled environment for treated artifacts, heavy duty sandblasting equipment, water distilling equipment, chemical supplies, drying ovens and electrolysis equipment (Townsend 1965; Watts and Bright 1973).

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This was the first State conservation facility to handle artifacts from a marine environment, and it predated the employment of a team of professional underwater archaeologists. The North Carolina General Assembly passed an Underwater Archaeology Law in 1967 (NC 1967) establishing state ownership of all historical and archaeological material (shipwrecks, vessels, cargoes, tackle, and artifacts) unclaimed for 10 or more years in state waters (within 3 miles of the coast) with NCA&H as custodian. NCA&H also gained the power to determine the disposition of the material, grant permits for exploration, recovery and salvage, and employ professional staff for ‘conducting and/or supervising the surveillance, protection, preservation, survey and systematic archaeological recovery of underwater materials’ (NC 1967).

Preserve through controlling the environment in order to minimize deterioration and loss of information and evidence. Arrest decay and stabilize against further deterioration, through interventive treatment if necessary—e.g., treatment to remove destructive agents such as soluble salts. Reveal, retrieve, and preserve archaeological evidence and information—e.g., through examination, X-radiography, and cleaning as necessary. Restore an object to a condition in which it can be understood, studied, and possibly exhibited—e.g., through cleaning or reassembly of broken parts.

Guiding principles in the practice of conservation include: • Avoiding falsification (whether structural or decorative). • Not removing or disguising the ‘ageing’ of original materials—e.g., ‘patinas’. • Not removing or replacing decayed parts. • Using treatments that are reversible wherever possible—e.g., when joining pieces together. • Leaving the object in a re-treatable condition. Some conservation processes are by their nature irreversible, such as removing corrosion products from a metal object to reveal its original surface. In recent years a more pragmatic alternative to reversibility is the principle that an object should be re-treatable (e.g., Oddy and Carroll 1999). • Adopting minimally interventive approaches, as the extent to which treatments can be irreversible has been recognized. • Documenting, through written and visual records, all the physical attributes of the object, its condition, treatments, results of examination and analysis, and the information revealed. • Disseminating findings and work done to colleagues, professionals, and the general public. • Performing research, review, reassessment, and revision of activities and treatments.

Funds for staff, however, were not made available until 1971 (Watts and Bright 1973) and staff were finally appointed in 1972. The first director of the NCUAB was Gordon Watts. Leslie Bright, hired as an untrained assistant in 1964, was the NCUAB conservator (or preservationist) until his retirement in August 1998 when he was succeeded by Nathan Henry, the current post holder. The laboratory at Fort Fisher continues to be the primary preservation lab for the NCUAB, except for artifacts recovered from the Beaufort Inlet Shipwreck. The NCUAB currently employs six permanent staff, with collectively approximately 100 years of experience in relation to underwater archaeology in North Carolina. Two are responsible for conservation of archaeological materials—the NCUAB Archaeologist/Conservator and the QAR Project Conservator.

Conservation of archaeological artifacts involves finding a balance between minimizing changes to the appearance, nature, and material of an object that might be caused by a change in its environment or by treatment, yet maximizing the retrieval of information and evidence.

Excavation and conservation of archaeological artifacts The excavation of an archaeological site, even by archaeologists, is a destructive process. The artifacts and ecofacts recovered may be the only contemporary material evidence that remains if excavation proceeds. Survival of the artifacts for present and future study, education, and enjoyment is therefore crucial. Upon excavation, there is potentially a sudden and drastic change to an object’s environment that can so destabilize the object that its condition can deteriorate rapidly and irreversibly. Conservation of archaeological artifacts aims to:

Continuity, change, and controversy: archaeological conservation The principle of conserving cultural artifacts is in general uncontroversial, although there may be debate over whether it is possible or necessary to preserve everything (Bomford 1994:3–4). The degree to which it is acceptable to change a cultural object is, however, a controversial topic, particularly when a familiar appearance is changed by adding or removing material. These debates are usually most heated in the field of art (e.g., Walden 1985; Beck 1993), although objects 48

SARAH WATKINS-KENNEY: GETTING THE JOB DONE (e.g., Pearson 1987; Hamilton 1996; Hamilton 1998). Sometimes developments are based on scientific research, such as the ongoing conservation of the royal Swedish warship Vasa (1628) recovered in 1961 (Roth and Malmberg 2005) or conservation of Mary Rose (1585) materials recovered between 1971 and 1982, with 10 years of research preceding the start of treatment of the hull (Jones 2003). Other developments have been more empirical. For example, between 1963 and 1973 at the NCUAB preservation lab, ‘because of the large numbers of identical objects recovered, it was feasible to use trial and error tests which in some instances caused destruction of artifacts’ (Watts and Bright 1973:132). Electrolytic reduction was used to clean and remove salts from ferrous metals. Various combinations of current flow, electrolyte concentration, and time, with respect to size and density of object, were tried to gain a ‘better understanding and control of treatment’ (Watts and Bright 1973:133). PEG was used for treating wet wood artifacts. Different concentrations of PEG in aqueous solutions were applied at different temperatures to wood of different sizes and densities over several years. It was found that higher molecular weight PEG was more successful on severely deteriorated artifacts, while lower molecular weights were better for less degraded items of greater density.

regarded as having archaeological significance are not immune, especially those that have achieved iconic status—the Elgin Marbles, for example (St Clair 1998; Jenkins 2001). When criticism of change comes from those outside the conservation field, with the external critics believing change has been for the worse and conservators taking the opposite view, the argument is rarely resolved (Bomford 1994). More constructive is internal controversy, which can be a mechanism by which standards are raised, and understanding and knowledge are increased. For example, in relation to materials and methods applied to archaeological materials, controversy can be salutary as it makes conservators think about, reassess, justify, and explain their actions, and if necessary, change how they work (Bomford 1994). With archaeological materials, such a debate might center around whether achieving stability is more important than preserving the evidence within the object; for example, hydrogen reduction treatment of marine cast iron confers high stability but may cause metallurgical changes (Barkman 1978; Tylecote and Black 1980). The only way to avoid acrimonious controversy is to debate issues openly with honesty and integrity—not always easy or possible in the face of personal prejudices and agendas (Bomford 1994). Some of the major challenges presented by objects recovered from the sea include soluble salts, concretions, stains, and the effects of waterlogging on organic materials. All artifacts will be saturated with soluble salts, particularly chlorides, which must be removed before an object is dried. If chlorides are left in metals they can promote corrosion to such a degree that the object disintegrates. If left in porous objects, such as pottery, salts can damage the physical structure as they expand upon crystallization. Hard concretions made up of deposits of calcium carbonate, shells, sand, and corrosion may envelop many artifacts of all materials, ranging in size from large cannons to tiny copper alloy pins, in a single large concretion. Iron objects that have completely corroded may only be represented as a void within the concretion. Wood may look in good, strong condition while wet, but much of its physical structure may be supported only by water at a cellular level; if allowed to dry without replacing the water with another bulking agent, collapse of cell structures causes irreversible shrinkage and distortion of the artifact.

Although key conservation materials may not seem to have changed much over the years, there has been a great deal of research leading to a better understanding of how and why treatments work or don’t work, and how best to apply them in order to better ensure success, particularly in relation to the conservation challenges presented by iron and by wood. Much of this research has been reported in conference proceedings, particularly of the triennial ICOM working groups for metals and for wet organic archaeological materials (WOAM), and in journals such as Studies in Conservation (International Institute for Conservation) since the 1950s. New treatment materials and methods have been introduced and tested such as freeze drying of organic materials (Grattan 1982; Watson 1982); stabilization treatments for iron such as hydrogen reduction (Barkman 1978; Tylecote and Black 1980) and alkaline sulphite (Gilberg and Seeley 1982; Beaudoin et al. 1997); different consolidants for organic materials such as sugars (Parrent 1985; Hutchings and Spriggs 2005) and silicone oils (Smith 2003); and in situ monitoring and anodic protection (MacLeod 2002). Some are still used, while others have gone out of fashion or have been found to be not effective, not safe (for objects or conservators), or not acceptable because they compromise archaeological evidence or are not reversible.

Treatments for artifacts from marine environments have their roots in the conservation of artifacts from land sites (dry and waterlogged) and can be traced back to at least the 19th century; an example is the development of conservation treatments for waterlogged wood recovered from bogs in Denmark (Christensen 1970). The main treatments still widely used for marine artifacts— polyethylene glycol (PEG) impregnation for wood, electrolytic reduction to clean and desalinate metals, tannic acid and waxes or lacquers as protective coatings for iron—were all in use by the end of the 1950s (e.g., Christensen 1970:33; Farrer et al. 1953; Plenderleith 1956). Over the years, these basic methods have been adopted and adapted for treatment of marine materials

In shipwreck archaeology two possible options are to survey and record a site or to excavate and recover the ship and its artifacts. Opinions can differ as to which presents the better strategy or best use of resources at a particular time (e.g., Rodgers et al. 2005; Fontenoy 2002). The decision to excavate a site requires not only an archaeological commitment but also a political one to 49

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS plan’s authors recommended Option 4, excavation with large-scale recovery, as the optimum plan to maximize archaeological and public benefit. Option 3, maintenance and limited exploration, was to be implemented until funds for Option 4 were available, and this has been the practice between 1999 and 2005. Conservation resources needed for both Option 3 and Option 4 were detailed in the management plan, since adequate and appropriate conservation provision were seen as key to success in realizing the potential of the site as a unique cultural resource for North Carolina.

support the project. There needs to be a commitment of time and resources in perpetuity, not just for the recovery phase but for conservation and study and then long-term storage and exhibition. Bass (2003) estimated the need to spend ‘an average of two years on conservation and library research for every month we dive. Raising artifacts is the easiest and least expensive part of the work.’ Continuity, change, and controversy: conservation and the Beaufort Inlet shipwreck Identification of the Beaufort Inlet Shipwreck has for some been a controversial issue (e.g., Rodgers et al. 2005). After nearly a decade of research, however, nothing has been discovered to refute the working hypothesis that the shipwreck is the Queen Anne’s Revenge (e.g., Moore 2005; Miller et al. 2005; Babits 2002). It is not the purpose of this paper to continue this debate; rather it is mentioned as one aspect of the context within which artifacts from the wreck are conserved. Working in this context certainly adds a particular level of excitement and anticipation to the conservator’s work—will the next piece of concretion removed reveal the definitive evidence?

Funding: Funding between 1997 and 2005 for operations under Option 3 has been sustained at an average of c. $204,000 a year, but from various sources and with the uncertainty of being on an annual basis. At this writing, funds for 2006 have still to be confirmed. Funding sources have included state annual appropriations and grants, and in-kind support from a wide range of agencies, private businesses, institutions, and individuals. Major grants have been received from the National Endowment for the Arts Save America’s Treasures program (SAT) (2002 to 2004) and the Golden LEAF Foundation (2005), with additional support coming from many others. Since 1997 the project as a whole has received about $1.8 million (Wilde-Ramsing and Watkins-Kenney 2005) from various sources for operations and temporary staff, in addition to the annual salaries of the two State-funded permanent NCUAB QAR staff (project director and conservator). Although there has been continuity of funding, its uncertainty and annual basis limits the extent of forward planning that can be done, takes a significant amount of the project director’s time, and affects the morale of those employed on a temporary basis, including conservators.

Management plan: Designation of the Beaufort Inlet Shipwreck site as a protected area in 1997 required the development of a management plan to guide all access, recovery, and conservation and dictated that all artifacts be kept as an intact collection in an appropriate repository (NCDCR 1997). The 1999 Management Plan authored by the project director and conservator (WildeRamsing and Lusardi 1999) reported on the 1997–1999 Assessment Project, including field investigations, historical research, and progress in artifact conservation. The plan presented four options for future protection, preservation, and study of the site, with associated advantages, disadvantages, prerequisites, and cost estimates: 1. Non-intervention—no further work, minimal monitoring and protection, no cost. 2. In situ preservation (burial)—site burial with annual monitoring and maintenance. Initial costs estimated at $100,000 per year; cost of annual monitoring and maintenance would depend on condition of site. 3. Maintenance and limited exploration (limited recovery)—site maintenance, surveillance, active monitoring, and mitigating threats to the site by stabilizing or recovery of artifacts and archaeological information. Continue exploratory site testing. Estimated annual cost $250,000, including conservation costs. 4. Excavation (large-scale recovery)—recover all or large proportion of site’s cannons, anchors, hull structure, and associated materials and information. Costs for staff, conservation laboratory, and exhibit hall estimated at a total of $6 million.

The conservation team: Initially, artifacts came under the care of the NCUAB State Conservator Leslie Bright at Fort Fisher, and his intern at the time, Nathan Henry. Since 1997, there have been three holders of the dedicated post of QAR Project Conservator: Nathan Henry (1997–1998); Wayne Lusardi (October 1998–June 2002); Sarah Watkins-Kenney (March 2003–present). Between June 2002 and March 2003, responsibility for the QAR artifacts reverted to Henry, assisted by two conservation technicians, Wendy Welsh and Mike Tutwiler, funded through the SAT grant. Since 2003, two additional NCUAB employees on the QAR conservation team have been an assistant conservator (Eric Nordgren) and laboratory manager (Wendy Welsh); these temporary positions are grant- or State-funded. Over the years, the QAR conservation team has always also included volunteers, interns, and paid ECU graduate assistants. Two of these have gone on to pursue conservation careers, one as a conservator with the USS Monitor Project and one to study archaeological conservation in London, UK. Between 2003 and 2005, ECU graduate assistants from the departments of Anthropology, Maritime Studies, and Coastal Resource Management have completed the team.

Given the vulnerability of the site to damage and dispersal by storms and hurricanes, and the costs and uncertain success of maintaining in situ preservation, the

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SARAH WATKINS-KENNEY: GETTING THE JOB DONE Conservation facilities: Not least of the challenges presented by the excavation of shipwrecks is that of finding suitable facilities in which to store, process, study, and conserve the wide range of artifacts recovered, requiring a lot of space and a lot of clean water. Conservation space and the QAR finds moved several times between 1997 and 2003 between Fort Fisher (NCUAB HQ), Morehead City (QAR Project HQ), and Beaufort (the North Carolina Maritime Museum’s facility at Gallants Channel).

3.

4. 5.

In 2002, a Memorandum of Agreement between ECU and the North Carolina Department of Cultural Resources (DCR; of which the Underwater Archaeology Branch is a section) finally provided space for a new QAR artifact conservation and research center at ECU’s West Research Campus in Greenville, North Carolina. ECU provides facilities, student graduate assistants, and consultation with faculty, while DCR is responsible for management of the shipwreck site and direction of the QAR Laboratory.

6. 7.

objects into wet storage, desalination of nonconcreted artifacts started. Assessment: examination (e.g., X-radiography of concretions); prioritizing conservation of artifacts based on examination, X-ray information, cultural and archaeological significance, stability, and condition. Excavation of concretions: recovery of artifacts from concretions, including casting voids with epoxy resin to recover form where original material is lost. Treatment: desalination, monitoring salt in solutions, drying, and application of protective coatings. Study and writing: completion of documentation, analysis, and reports for publication. Transfer to museum: pack objects for transport, including associated documentation and recommendations on the care of objects. Conservators are available to assist with monitoring the condition of artifacts, providing advice, and doing further treatment if necessary.

Documentation, both visual (photography and drawings) and written (lab sheets and database records), is ongoing through all of the above stages. The QAR artifact master database is held at the QAR lab. The QAR Artifact Database, as part of the DCR statewide artifact database, will be held centrally at the Office of State Archaeology in Raleigh, available to future researchers.

Construction for the new lab, the NC Queen Anne’s Revenge Archaeological Conservation Laboratory, began in February 2003. The location has good ground-level access to buildings for large vehicles and artifacts, and space with the potential for development and expansion of conservation, research, and education activities. The main building has c. 1200 sq. ft. including a wet/dirty small objects lab, a small clean-work lab, offices, and artifact study areas. A warehouse (4,000 sq. ft.) on the same site is equipped for the storage and treatment of large objects (cannon, ships timbers) and electrolytic reduction treatment of metal finds. With a construction budget of c. $52,000 and much creative recycling (e.g., from ECU surplus warehouses), a functioning conservation facility has been established that complies with ECU’s environmental, health, and safety requirements. Generally the facility is excellent for its purpose, apart from not being on mains sewage so all chemical waste has to be removed from the site. Health, safety, and environmental considerations determine choices made in the selection of conservation materials; for example, sodium carbonate solutions are the main electrolyte rather than sodium hydroxide solutions. Development of the lab continues as funding becomes available.

Laboratory records include several thousand digital images that record artifacts before, during, and after conservation. Given the changes in conservation staff and facilities, these conservation records are an essential part of ensuring continuity of treatment, as well as dissemination of information. QAR conservation progress 1996–2005 Since the discovery of the wreck, there have been three phases in the conservation, documentation, and the study of artifacts. 1997–2000: Investigations and monitoring of the site, limited excavation and recovery of artifacts; conservation for museum display of ‘star’ objects; storage for most concretions (c. 250); recovery from concretion of five of six cannon and start of their desalination; X-radiography of some concretions; establishment of a QAR conservation and storage facility in Morehead City (1999/2000); appointment of QAR Project Conservator; defining future conservation needs in a Management Plan (1999); analysis of various artifacts, e.g., identification of woods, analysis of corrosion products on pewter and lead, and geological study of ballast stones.

QAR conservation and the archaeological process The QAR conservation team is involved at all stages of the archaeological process from planning and recovery, through treatment and documentation, to study, storage, and display of artifacts at the Maritime Museum in Beaufort. There are seven stages of conservation activity as artifacts pass from the site through to the museum: 1. Recovery: planning and preparation, in the field during excavation, initial documentation, first aid wet storage, transport to lab (e.g., Watkins-Kenney 2005). 2. Post-recovery: processing (weighing, photography), lab record sheets and database records established,

2001–2003: QAR conservator position vacant 2002– 2003; closure of conservation facility at Morehead City (basic storage and treatment space for cannon and hull timbers continued); processing and recovery of artifacts from concretions transferred to Fort Fisher NCUAB lab—some 200 broken down yielding approximately 20,000 individual pieces (of which c. 15,000 were lead 51

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS education and public involvement has been achieved in various ways, from a Dive Live link during excavations in 2000–2001, to radio interviews, newspaper articles, and TV documentaries. Reports on the many and varied project activities, including a bi-monthly conservation report, are posted regularly on the web page at www.qaronline.org. Conserved artifacts are transferred to the NC Maritime Museum in Beaufort for storage and public display. The QAR Lab also disseminates information through publications and presentations at seminars and conferences. A free Open Day for the general public to view and discuss artifacts undergoing conservation was held as part of North Carolina Archaeology Month in October 2005.

shot and c. 1200 were ballast stones), some recovered as castings (e.g., cask hoops and fasteners); artifacts into wet storage at Fort Fisher; artifact database designed and developed. 2003–2005: Establishment and development of QAR Lab at ECU in Greenville; appointment of QAR project conservator, assistant conservator, and lab manager; transfer of all finds to QAR Lab in Greenville from Fort Fisher and Morehead City; concentration on completing desalination (e.g., of ceramics, glass, bone, 800 nails, cannon); transfer of artifacts to NC Maritime Museum; artifact database piloted and into operation; transfer of records to the database; documentation and study of artifacts for QAR Reports; recovery and processing of artifacts in May 2005 field season; planning for next phase of QAR Project and development of conservation facility. QAR research and technical reports are posted on the project’s web site at www.qaronline.org.

The shipwreck provides a unique resource for national and international researchers in both material culture and materials science. Over the years, the project has worked with a number of researchers in universities in North Carolina and beyond. A number of studies of the artifacts and their conservation have been published (e.g., Lusardi 1999; Moore 2001; Craig et al. 2001; Dunkel et al. 2003; Watkins-Kenney et al. 2005). Some of the findings were presented at a symposium at ECU in April 2005. Links with researchers in a variety of ECU departments and programs (e.g., Maritime Studies, Anthropology, Coastal Resources Management, Physics, Interior Design and Merchandising) have been and continue to be developed. Dr. Runying Chen, a textile expert, has examined and identified fibers from cannon wads (Chen and Lusardi 2001) and is currently researching methods for stain removal from rope, cannon wads, and textiles in collaboration with the QAR conservation lab.

For the QAR Project there have been approximately six months total of field work over nine years, 1997–2005. Based on Bass’s (2003) estimate of two years conservation and study for every month in the field, at least another three years of conservation and study are needed to complete work on artifacts recovered so far; this is realistic in view of the rate of progress so far. Approximately two years of conservation and study time have been lost due to staff changes and moving facilities. Public outreach, education, and research The extent to which the public, and which public, should be involved in underwater archaeology are controversial issues. Several papers taking different views in this debate can be found in Babits and Tilburg (1998:55– 111), from those who think that underwater archaeology should be the exclusive preserve of professional archaeologists, to professional archaeologists who aim to include sport and hobby divers and amateur archaeologists, even those who are searchers of historical relics (viz treasure hunters).

Another aspect of the North Carolina underwater archaeology program has been its commitment to education through partnerships with colleges and universities (Watts and Bright 1973). A partnership with ECU’s History Department began in 1979. ECU summer field schools (1979–1981) carried out surveys and site assessments of North Carolina colonial harbors to assist with the State’s management responsibilities for submerged cultural resources while training students in underwater archaeology. This led to the creation in 1981 of ECU’s graduate degree program in Maritime Studies, under the direction of Dr. Still and Dr. Gordon Watts, who resigned his post as NCUAB director to take the ECU position. Over the years much of ECU’s Maritime Studies program has continued to focus on the State’s underwater sites and has involved the NCUAB (WildeRamsing and Watkins-Kenney 2005). The Maritime Studies program includes a course on Conservation of Material from an Underwater Environment, providing ‘a comprehensive introduction to and preliminary laboratory experience in the conservation of material from an underwater environment’ (ECU Maritime Studies 2005). As a working conservation lab linked to a major ongoing archaeological project, the QAR lab also provides opportunities for education in conserving artifacts from a marine environment for students at ECU and potentially for a wider community of archaeologists, museum staff, and other professionals.

Between 1962 and 1973, NCA&H aimed to protect and explore North Carolina’s underwater archaeological resources by involving the public as much as possible in all phases of operations, not only because of the lack of funds but also because of a commitment to education. This approach resulted in greater understanding and cooperation between the diving community and NCA&H. Through the permit system the state avoided denying public involvement and minimized diver hostility over the State’s claim to ownership of sites under the 1967 Act (Watts and Bright 1973). The involvement of volunteers also provided another ‘opportunity for citizens of the state to make valuable contribution to the understanding and preservation of their heritage while participating in an educational experience’ (Watts and Bright 1973). Informing and involving the public has been a priority for the QAR project team, including conservation. Continuing the North Carolina DCR commitment to 52

SARAH WATKINS-KENNEY: GETTING THE JOB DONE of the effects and effectiveness of treatments, should lead to continuous reassessment of methods and treatments used. Conservation is an evolving discipline; as examination techniques and available expertise improve, particularly in understanding the evidence that may be preserved and retrievable, conservators are better able to understand the short- and long-term effects of treatments.

Conclusion Long-term projects such as the QAR Project inevitably face the challenges of continuity, change, and controversy. Project management needs to accommodate these three Cs in a positive and constructive way to ensure that the project progresses. The challenge is to maintain a balance between them: • Too much emphasis on continuity can lead to stagnation, unwillingness to accept change, and an inability to handle controversy. • Too much change can lead to loss of expertise, loss of continuity, lack of progress, too much time spent in adapting, reviewing, and revising, and never getting the job done. • Too much controversy can result in neither change nor continuity and can lead to the end of the project.

An indication of good conservation practice is not slavishly following a dogmatic process, e.g., not necessarily using exactly the same treatments all the time, or using as the only reference for treatments textbooks that are over 30 years old (Plenderleith and Werner 1971, or even Pearson 1987). Practice should be kept up to date with an awareness of research and developments. Jones (2003), in discussing conservation of artifacts from the Mary Rose over the last 20 years, acknowledges that some treatments described are not likely to be used now.

Management of long-term projects does not best operate with a one-step linear approach—plan, acquire resources, implement—but actually involves a continuous cycle of planning, practice, review, and revision (Fig. 1). Change such as an injection or loss of resources (staff, facilities) or a change in the condition of the site instigates review and revision of the plan.

The online QAR Conservation Reports describe conservation of artifacts since 1997. Some of the early treatments described are no longer followed (e.g., removing all stains from clay tobacco pipes, or buffing and polishing pewter); and it is likely that those reading today’s reports in the future will raise their eyebrows at some of the things done now because they will no longer represent best practice.

PLAN REVISE

This paper has avoided addressing the potentially controversial issue of who actually conserves archaeological artifacts: archaeologist, archaeological conservator, conservation scientist, volunteer, treasure hunter, or whoever. Rather, the focus has been to identify what needs to be done, how to do it, to what standard, and with what underpinning knowledge and understanding. In fact, many people, including administrators and politicians, need to be involved in and committed to conserving archaeological artifacts if projects are to succeed. Conserving artifacts is not an activity that can be done in isolation—conservators are part of the archaeological process and have a key role in the archaeological team. Those archaeological conservators who take a professional approach to their work are guided by unifying codes of practice and ethics (e.g. UKIC Archaeology Section 1990; AIC 1994). Ultimately, however, the nature, extent, and success of practical application will depend on how conservators manage continuity, change, and controversy within the context of archaeology.

PRACTICE REVIEW

Figure 1: The planning cycle.

As presented on paper, a planning cycle appears twodimensional; there is, however, a third dimension, that of time. The cycle would be more accurately viewed as a coil or even a slinky—with the time axis perpendicular to the plan, practice, review, revise cycle. Continuing this slinky metaphor, a healthy project needs to be flexible, not too rigid or tightly coiled. Over-management would be a tight coil with too short a time period between each stage, leaving no time to actually put the plan into practice. Likewise, archaeological conservation should also involve a constant cycle of planning, practice, review, and revision rather than a linear ‘cookbook’ approach. Standard treatments can be described in textbooks but rigid application of these without knowledge, understanding, and experience of materials science or of the archaeological potential of an object can cause problems. The opposite can also cause problems—i.e., varying the treatment too much on a trial and error basis, from one that has been rigorously researched. Archaeological conservation should not be regarded as a linear process but as a cycle. Feedback from dissemination of findings, and review, particularly as conservation research/science deepens our understanding

Acknowledgements The author would like to thank Richard Lawrence, Mark Wilde-Ramsing, and John Kenney for their help and advice on this paper. Bibliography AIC. 1994. American Institute for Conservation Code of Ethics and Guidelines for Practice. Washington, DC: American Institute for Conservation.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS State Archaeology – Underwater Archaeology Branch, Queen Anne’s Revenge Archaeological Conservation Laboratory. She is also, since 2008, a PhD candidate in the Coastal Resources Management Program at East Carolina University, North Carolina.

Watkins-Kenney, S., E. Nordgren, W. Welsh, and N. Henry. 2005. The Queen Anne’s Revenge Shipwreck Project: recovery, examination and treatment of wood. In Proceedings of the 9th ICOM Group on Wet Organic Archaeological Materials Conference, Copenhagen 2004, eds. P. Hoffmann, K Straetkvern, J. Spriggs, and D. Gregory, 389-403. Bremerhaven: ICOM Committee for Conservation Working Group WOAM.

Address Chief Conservator NC QAR Archaeological Conservation Laboratory 1157 VOA Site C Road West Research Campus East Carolina University Greenville, NC, 27834 USA

Watson, J. 1982. The application of freeze drying on British hardwoods from archaeological excavations. In Proceedings of the ICOM Waterlogged Wood Working Group Conference, ed. D. Grattan, 237-242. Ottawa: Waterlogged Wood Working Group, Committee for Conservation, ICOM. Watts, G. 1985. Towards establishing research and significance criteria for Civil War shipwreck resources. In Maritime Archaeology: A Reader of Substantive and Theoretical Contribution, eds. L.E. Babits and H. Van Tilburg. New York: Plenum Series in Underwater Archaeology. Watts, G., and L. Bright. 1973. Progress in underwater archaeology in North Carolina 1962-72. International Journal of Nautical Archaeology 2 (1): 131-136. Wilde-Ramsing, M. 2005. Queen Anne’s Revenge Shipwreck Project Archaeological Recovery Plan – May 2005 Expedition. NC Department of Cultural Resources, QAR Project Archaeology Field Reports. www.qaronline.org/QARMayrecoveryplanfinal .pdf. Wilde-Ramsing, M., and W. Lusardi. 1999. Management Plan for North Carolina Shipwreck 0003BUI, Queen Anne’s Revenge. NC Underwater Archaeology Unit, Division of Archive and History, Department of Cultural Resources (unpublished). Wilde-Ramsing, M., and S. Watkins-Kenney. 2005. NC Queen Anne’s Revenge Archaeological Conservation Laboratory, ECU West Research Campus. Briefing notes Appendix III. September 2005. On file at NC Underwater Archaeology Branch. Biography Sarah Watkins-Kenney has a BSc degree in archaeological conservation from Cardiff University, UK (1977) and an MA degree in museum and gallery management from City University London, UK (1994). She has worked as an archaeological conservator for a range of organizations including museums, universities, and regional conservation services in the UK. She was Head of the Metals, Ceramics and Glass Conservation Section at the British Museum from 1994 to 2003. She is a Fellow of the International Institute for Conservation (FIIC); an Accredited Conservator (ACR) and Accredited Member of the UK Institute of Archaeology (MIFA). She is currently Chief Conservator at the North Carolina Department of Cultural Resources Office of 56

A WOODLAND BURIAL STUDY: DEVELOPING METHODOLOGIES FOR MONITORING AND MODELING THE BURIAL ENVIRONMENT Karla Graham and Peter Crow Abstract The Woodland Burial Study is a collaborative project between the research section of the Forestry Commission (Forest Research) and English Heritage to devise methodologies to study and determine how land use (particularly woodland) and soils affect the preservation of archaeological remains in situ. Since the early 1990s, Forest Research has monitored 10 forest sites to examine environmental change; monitoring includes the chemical analysis of atmospheric deposition, soils, soil solutions, and soil mineral weathering rates. The latter have been found to show differences between the sites and between their individual soil horizons. Expanding on this work, English Heritage, in conjunction with Forest Research, is undertaking a feasibility study to develop methodologies for monitoring and potentially modeling the archaeological burial environment. This is relevant as the Government’s forestry policy is committed to the expansion and sustainable management of forests. Therefore, it is necessary to understand any potential interactions with buried archaeological remains.

the Forestry Commission delivers scientific research and surveys to inform both the development of forestry policies and practices, and standards for sustainable forest management. A changing environment In the UK, cultural and environmental changes increasingly pose challenges to the preservation of the historic environment in both urban and rural contexts. Cultural changes include urban and rural management policies and strategies. Development pressures for additional housing, industrial expansion, and associated transport networks are creating pressure on the rural environment and resulting in land use changes. Shifts in agriculture and nature conservation practice include the growing demand to move from the use of fossil fuels to renewable energy sources (biomass crops) to fuel power stations. Whilst biomass crops such as Short Rotation Coppice (SRC) are carbon dioxide neutral, there is potentially a high impact on the archaeological burial environment through an increased uptake of water (Hall 1996) and associated cultivation (Tubby and Armstrong 2002). The change from agricultural land use to Countryside Stewardship Schemes (CSS) involves transforming land management practice to enhance the countryside landscape, encourage wildlife, and protect the historic environment (Department for Environment, Food and Rural Affairs 2005a). These can involve dramatic alterations to the burial environments, such as the rewetting of previously drained agricultural landscapes. Climate change scenarios predict changes in temperature, precipitation patterns, and groundwater levels that will potentially impact upon the historic environment (Cassar 2005). Rising sea water levels combined with changes in coastline management policies mean that coastal areas are subject to erosion and marine transgression and the burial environment subjected to new saline environments (Murphy and Trow 2004). These factors can all potentially impact directly and indirectly upon buried archaeology; they risk causing damage to the physical remains and the loss of information on the historic environment.

Introduction The Woodland Burial Study is a collaborative project between the research section of the Forestry Commission (Forest Research) and English Heritage to determine how land use (particularly woodland) and soils affect the preservation of archaeological remains in situ. The project involves specialists from different disciplines (environmental scientists and archaeological conservators) collaborating to address similar archaeological management issues. The project builds upon a solid foundation of research undertaken by Forest Research (long-term environmental monitoring and mineral weathering studies) and incorporates archaeological aspects to utilize this data. The practice of investigative conservation involves applying scientific techniques to examine finds and reveal information concerning manufacture, use, and deposition. It involves both an understanding of materials science (how materials behave and the processes of deterioration) and the appropriate application of scientific techniques— skills that are transferable to preservation in situ projects. Investigating the rates and processes of decay of a range of materials, in a variety of burial environments, requires a multidisciplinary approach to place observed trends in the context of a dynamic burial environment.

Planning and mitigation Central Government has given main responsibility for the planning and development of urban and rural areas to Local Government authorities (at the level of County and Metropolitan borough). The Local Government planning authorities regulate the use of land to meet sustainable development principles; they must reconcile the need for economic growth and development with the need to protect the natural and historic environment (Department for Environmental Food and Rural Affairs 2005b). The historic environment is a finite and non-renewable resource, and Planning Policy Guidance Note 16 (PPG16) was introduced by the Government in 1990 to

English Heritage is the UK government-funded public body responsible for understanding, promoting, and protecting England’s historic environment and advises both Central and Local government. The Forestry Commission is the UK body responsible for forestry policy. Its mission is to protect and expand the UK forests and woodlands, to promote their sustainable management, and to increase their value to society and the environment. Forest Research, the research section of 57

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS ensure that archaeology was fully incorporated as a material consideration in the planning process (Department of the Environment 1990). PPG16 outlines that the reburial and in situ preservation of all forms of archaeological remains is the preferred management strategy and this principle is further supported by the Valletta Convention (Council of Europe 1992). Only when physical preservation is not feasible should preservation by record (i.e., excavation) be undertaken. Developers are required to determine if archaeological remains are present on a site proposed for development. If present, they must evaluate the value of the archaeological remains, assess the potential impact of their development on them, and mitigate against the impact to preserve the archaeological remains in situ.

Woodlands and archaeology Currently 12% of Britain is under woodland management (27,310 km2 / 2.7 million ha). The UK government is committed both to the expansion of woodland cover and to the conversion of woodlands from non-native trees such as conifers to those comprising native species such as oak, ash, and beech (Forestry Commission 2005). The Forestry Commission is committed to sustainable forestry and has responsibility to mitigate damage to important known and potential historic environment remains both during woodland management and when promoting expansion. Due to limited surveys and research, however, less is known about the extent and condition of historic environment features in woodland landscapes compared to other land uses. Since 1988 all applications for new woodland grants have required consultation with local authority archaeological curators and a risk assessment of potential impact to be undertaken for each proposal. There has been an increased awareness of the issues challenging the historic environment by wooded landscape and their management strategies. Issues include the physical and chemical effects of root growth and the influence of trees on atmospheric deposition (trees will alter the chemistry of the deposition reaching the soil), soil solution chemistry and site hydrology (Crow and Moffat 2005). As with other landscape types, however, the curators still require guidance on the effective management of the historic environment in this type of land use.

For the archaeological curators (Local Government archaeologists) who are responsible for advising the planning authorities and developers on the historic environment and preservation in situ, it is essential that they are able to make informed choices regarding available management options. The two Preserving archaeological remains in situ conferences (Corfield et al. 1998; Nixon 2004) have been important for the archaeological discipline highlighting the preservation in situ issues and providing multidisciplinary case studies of monitoring and mitigation strategies. However, whilst the concept of preservation in situ has been promoted since the 1990s, the necessary research to underpin protocols and guidelines for its successful implementation has not been available. Current research is intended to further contribute to the knowledge necessary for evidence-based policies and practical guidance. To increase our understanding of the efficacy of in situ preservation strategies there first needs to be an agreement of what is meant by preservation in situ. Indefinite preservation in situ would involve the physical and chemical state of the archaeological resource remaining unaltered for an indefinite period. Deterioration is inevitable, however, since the burial environment is a dynamic, complex system undergoing physical, chemical, and biological changes that have consequences for the preservation of the archaeological resource contained within it. Preservation in situ should be viewed as a strategy that aims to reduce the rate of deterioration as much as possible.

Long-term environmental studies Forest Research is undertaking the long-term monitoring of forest ecosystems as part of a European-wide network called the Level II Program. The program was established under European Union legislation in1994 in response to concerns about acid rain, air pollution, forest decline, and soils acidification by afforestation. The main objective of the network is to assess changes within forest ecosystems and to determine the causes of these changes (Durrant 2000). Ten UK sites have been intensively monitored to detect changes in the environment and condition of forest ecosystems and to determine the impact of woodland cover and depositional inputs into the soil. The sites represent a range of soil types and the three major UK woodland types: Sitka spruce (Picea sitchensis), Scots pine (Pinus sylvestris L.), and oak (Quercus spp.). Data on a large number of parameters is recorded on a regular basis at these sites and outlined in Table 1

A suggested approach would require a detailed characterization of the extent and condition of the historic environment resource from sites and landscapes to buried structures, deposits, artifacts, and ecofacts. Baseline information is required on what is to be preserved in situ, i.e., the range of materials, their condition, and preservation requirements. An understanding would be required of both the dynamic processes that occur within the burial environment and their affect on archaeological remains, and the implications of land use and change for the preservation in situ of archaeological remains.

The cause-effect relationships for chemical inputs (acid rain and air pollution) into woodland ecosystems have been defined using the ‘Critical Loads’ concept (Loveland 1993). Critical Loads are the threshold rates of pollutant (such as sulfur dioxide) beyond which significant damage to the forest ecosystem is believed to occur. To determine the critical loads of acidity for forest soils, the weathering rates of soil minerals must be determined, as the liberated base cations are able to neutralize any acidic input from deposition. To directly assess site-specific weathering rates, seven types of 58

KARLA GRAHAM AND PETER CROW: A WOODLAND BURIAL STUDY soils). As with the other Forest Research monitoring sites, the 0.3 ha study area forms part of the wider forest and is under the same forest management regime as the rest of the forest.

reference minerals were buried in 1997 at all the monitoring sites. The minerals were placed in different soil horizons and replicate sets were buried at each site to allow recovery at different time intervals. The study has a 10-year recovery program and to date, three sample sets have been recovered from each of the monitoring sites.

The aims of the study are as follows: To undertake the burial of a variety of modern analog materials representative of a wider range of archaeological material. • To develop methodologies for monitoring the rates of degradation of analog materials. • To develop methodologies for monitoring the archaeological burial environment: directly correlating material degradation both with its immediate burial environment and the parallel mineral weathering study (the last mineral set is due to be removed in 2007). • To determine how land use affects the preservation of archaeological remains in situ. • To advise on the feasibility of expanding this study to a long-term project at a number of woodland and possibly other environmental monitoring sites. •

The minerals were initially selected to represent a range of weathering susceptibilities within the soil. However, due to the minerals’ occurrence within some archaeological materials and their chemical similarity to others, the mineral rates can be compared to some types of archaeological evidence (Table 2). Examples of archaeological material that can be considered include plaster (gypsum), ceramics (vermiculite, biotite, and microcline feldspar) and teeth and bone (apatite). Methods of analysis to assess weathering rates include percentage loss, surface chemistry (exchangeable cations), scanning electron microscopy, and X-ray diffraction analysis. Geochemical modeling of the burial environment was undertaken alongside the mineral weathering using a computer program (Phreeqci) from the United States Geological Survey (US Geological Survey 2005). The program utilizes soil solutions obtained from tension lysimeters installed at the monitoring sites. By entering the chemical analysis data from the lysimeters into Phreeqci, the dissolution and precipitation susceptibilities for a range of soil minerals in the surrounding soil is modeled. The saturations indices (SIs) derived from the monitoring sites were plotted against the actual quantities of reference sample lost in the same horizon. Figure 1 shows the similarity between the predicted and actual loss for three of the test minerals.

Modern analog samples The archaeological analog materials comprise ferrous and nonferrous metals, red deer antler, cattle horn, and cotton. The materials range widely in the mechanisms via which they degrade (chemical, physical, and biological) and their susceptibility to degradation. The material types were selected not to replicate archaeological finds, but to represent a range of materials in archaeological finds; for example, the cotton is 96% cellulose and is being used as a substitute for wood. This type of cotton has been used as a standard for a number of other experimental monitoring projects (Palma 2004). Archaeological copper alloys comprise copper alloyed with different metals in varying percentage compositions. For the purpose of the study, a standard was required as a baseline from which to directly monitor the reaction of nonferrous metal with its burial environment. Modern unalloyed wrought copper (British Standards Institute 2002) was selected as it is of known composition and condition; it is easily sourced and thus can be replicated, allowing for direct comparisons to be made between this and other monitoring experiments using it in the future. It was selected rather than a copper alloy to remove the influence of other metals and reduce the number of variables in studying the reaction of the metal within its burial environment.

The similarities between the trends in predicted and actual loss from one site to another suggest that a simple aqueous soil extract could be used to indicate the susceptibility of a range of soil minerals in that burial environment. If archaeological materials can be compared to some of the soil minerals, their potential for preservation in situ can be examined. Whilst providing information for the management of surviving archaeological evidence, the SIs also have the potential to indicate what types of material may have been lost from a site. The challenge is to determine what archaeological materials can be related to which soil minerals and how to convert SIs into rates of loss.

Analog burial The burial methodology used needed to ensure the samples were incorporated within known soil horizons and that they made intimate contact with the soil. There should be minimal disturbance to the burial environment being studied and no interference should occur either between the samples or between the samples and the monitoring devices. The samples were buried according to a system devised by Forest Research for burying the study minerals at the monitoring sites.

Archaeological analogs To expand the mineral weathering work to directly include wider archaeological aspects, the English Heritage Archaeological Science teams were approached in 2004 to undertake a collaborative project with Forest Research. The resulting feasibility study is currently being undertaken at one of the monitoring sites: Alice Holt Forest, southern England (Fig. 2). Alice Holt is an ancient forest site with an oak plantation comprising clayey, seasonally waterlogged soils (Pelo-stagnogley 59

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS

Parameter Soil survey and analysis Foliar analysis Soil solution analysis (tension lysimeters), two depths Throughfall deposition (TF) analysis Open deposition or bulk precipitation (BP) analysis Tree growth rates Crown condition Meteorology Ground vegetation Litterfall

Number of sites where parameter is recorded 10 10 6

Frequency of measurement

10 10

2 weeks 2 weeks

10 10 8 10 4

5 years Annual Hourly-daily 3 years 4 weeks 2 weeks (autumn)

10 years Annual 2 weeks

Table 1: Parameters recorded by Forest Research at the UK monitoring plots. Mineral Gypsum

Formula of mineral or group CaSO4.2H2O

Occurs in / represents Gypsum plasters. Found in some ceramics.

Apatite

Ca5 (PO4)3 (OH,F,Cl)

Vermiculite

(Mg,Ca)0.6-0.9 (Mg,Fe3+,Al)6 ((Si,Al)8O20) (OH)4.nH2O

Hydroxyapatite, Ca5 (PO4)3 OH, is the main mineral component of teeth and bone. Found in ceramics (clay component).

Biotite

K2(Mg,Fe2+)6 (Si3AlO10) (OH,F)4

Hornblende

Ca2(Mg,Fe)4 Al (Si7AlO22) (OH)2

Found in ceramics (clay or temper).

Common in igneous rocks. May be found in some igneous stone axes (e.g. tuff, dolerite). Microcline KAlSi3O8 Found in igneous rocks, metamorphic rocks, and feldspar some clays. Potentially found in ceramics (clay or temper), porcelain, and impurities in glass. Represents some glasses. Common in igneous rocks, metamorphic rocks, and Tourmaline (Na,Ca)(Mg,Fe,Mn,Li,Al)3 (Al,Mg,Fe3+)6 (Si6O18) (BO3)3 (O,OH)3 some sands. May occur in granite structures. A (OH,F) silicate mineral with high chemical resistance. Represents more stable silicates such as flint. Table 2: Minerals used in the woodland soil monitoring study, and the type of archaeological evidence they represent.

Material

Method of analysis

Type of information

Copper

• • • • • • • • •

Surface area of corrosion products X-ray diffraction analysis Weight of corrosion products X-ray diffraction analysis X-ray fluorescence analysis X-ray diffraction analysis Scanning electron microscopy microprobe Fourier-transform infrared spectroscopy Standard cotton strip tensile tests

• • • • •

Corrosion rate Determine crystalline corrosion products Corrosion rate Determine crystalline corrosion products Rate of decay and processes of deterioration

•

Residual strengths of the fabric strips and hence infer their relative damaged state

•

Fourier-transform infrared spectroscopy

•

Relative crystallinity of the residual cellulose

•

Scanning electron microscopy •

Gross structural damage to fibers and presence of fungal invasion

Iron Antler and horn Cotton

Table 3: Methods of analysis for the modern analog samples.

60

KARLA GRAHAM AND PETER CROW: A WOODLAND BURIAL STUDY

Apatite

717d

715d

516d

512d

922s

920s

919s

717s

715s

516s

0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0

10 5 0 -5 -10 -15 -20 -25 -30 -35

Mineral loss (%)

SI

512s

Sampling site

Biotite

0.0

10

-1.0

5

-2.0

0

-3.0

-5

-4.0

-10

-5.0

SI

15

Mineral loss (%)

922d

920d

717d

517d

516d

512d

922s

920s

919s

717s

716s

715s

517s

516s

512s

Sampling site

Tourmaline

922d

920d

717d

716d

517d

516d

512d

922s

920s

919s

717s

716s

715s

517s

516s

0.6 0.4

0.0

0.2 0

-1.0

-0.2 -0.4

-2.0

-0.5 -1.5 -2.5

-0.6 -0.8

-3.0

Figure 1: Comparison of the predicted Phreeqci SI (shown by a broken line) for three minerals with the actual percentage loss after 5 years (shown by a solid line)

61

Mineral loss (%)

SI

512s

Sampling site

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS

Figure 2: Alice Holt monitoring site showing throughfall collectors.

Figure 3: Burial site plan showing the positions of the monitoring equipment relative to the burial trench.

62

KARLA GRAHAM AND PETER CROW: A WOODLAND BURIAL STUDY

100

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

90

Soil moisture (%)

80 70 60 50 40 30 20 10

10 cm 20 cm 30 cm 40 cm 60 cm 100 cm Rainfall

21 /6 / 23 200 /6 5 /2 25 00 /6 5 / 27 200 /6 5 /2 29 00 /6 5 /2 0 1/ 05 7/ 2 3/ 005 7/ 2 5/ 005 7/ 20 7/ 05 7/ 2 9/ 005 7/ 2 11 00 /7 5 / 13 200 /7 5 /2 15 00 /7 5 / 17 200 /7 5 /2 19 00 /7 5 / 21 200 /7 5 /2 23 00 /7 5 / 25 200 /7 5 /2 27 00 /7 5 / 29 200 /7 5 /2 31 00 /7 5 /2 0 2/ 05 8/ 20 4/ 05 8/ 2 6/ 005 8/ 20 8/ 05 8/ 20 05

0

Rainfall (mm)

Site monitoring data

Figure 4: Soil moisture content at six depths plotted against precipitation for the period mid-June to August 2005.

A small trench measuring 1.3 m by 1.1 m was hand excavated to a depth of 1.2 m. Each soil horizon was separated out and retained to ensure back-filling in the correct horizon order. Samples were installed within three soil horizons in two walls of the trench (at depths of 0.1, 0.38, and 0.9 m). For each set of samples, a broad flat chisel was driven into the wall of the trench, lifted slightly and the sample inserted in the gap underneath. The samples were pushed 0.13 m into the horizon and then the chisel removed. This method means that the samples are inserted into the appropriate horizon with the soil immediately above and below the samples remaining relatively undisturbed.

the samples from the ground and immediately placing them in a contained environment with an oxygen scavenger. The container is constructed from a tube roll of laminated barrier film (Escal®) that protects against the ingress of oxygen and water vapor. The oxygen scavengers placed inside the tube remove oxygen, moisture, and corrosive gases (Revolutionary Preservation [RP] System Type A, Mitsubishi Gas Chemical Company). Oxygen and relative humidity indicators are also placed inside, and the ends of the tubing are hermetically sealed with Escal® clips. The samples are stored in these containers until the moment of analysis.

The samples were spaced out within the horizon to avoid the materials having any effect on each other. A second set of samples was installed in the opposing wall in case of loss or damage to the first set or to allow the opportunity of retrieving them after a longer period of time. The experimental period will be six months: the first set of samples will be removed in January 2006 by excavating directly down from above them.

All the materials will be analyzed with the aim of characterizing the type and rates of decay and corrosion. The analysis methodologies for each material are outlined in Table 3. The results for the materials will be assessed in the context of the site and burial environment monitoring information outlined below, and the results compared between the soil horizons. Monitoring the burial environment The aim of the monitoring is to determine the quantity and quality of water in the burial environment, the chemical status of the burial environment, and the depositional inputs into the ecosystem. Every two weeks, as part of the ongoing environmental monitoring program, Forest Research measures a range of environmental parameters in close proximity to the burial site. This includes tension lysimeters (at two different depths) to collect soil solutions for analysis. The chemistry of the soil solution is analyzed by Forest

Methodologies for reducing post-excavation degradation will be assessed, including the use of oxygen-free storage systems for metal samples. These systems, developed for industry (food and engineering), have been used in recent years for conservation applications such as the preservation of materials highly susceptible to oxidation (Shashoua and Thomsen 1991). This will continue a study of the application of oxygen-free systems initiated for a separate experimental monitoring project (Graham 2005). The system involves removing 63

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Research and includes pH, conductivity, ionic composition, dissolved organic carbon (DOC), alkalinity and saturation indices (modeled for a range of soil minerals from the above chemical data). Other environmental measurements include rainfall, temperature and deposition volume and chemistry (both in woodland and open settings). The burial study will use this long-term environmental monitoring data both as typical values for the site (such as soil horizon pH) and at a more detailed level for the duration of the burial study (such as deposition chemistry which changes throughout the year).

Discussion The long-term monitoring undertaken by Forest Research has shown that environmental impacts on the burial environment are site specific. The mineral weathering studies indicate that each soil horizon has its own set of hydrological and chemical properties and it is therefore not possible to use soil type alone to predict the impact upon the archaeology contained within. These studies have shown to date that there are three primary conditions that have controlling influence on mineral weathering: soil pH, soil solution saturation, and soil water movement. A soil solution saturated with a particular ion or chemically similar ions to those of the artifact is more likely to favor preservation (Raiswell 2001). Thermodynamics will cause the dissolution of ions from archaeological materials until the ions in solution are in equilibrium with the ions in the solid archaeological material. The rate at which the dissolved ions are removed from the area of saturation surrounding a find and the level that the ion concentrations are diluted will be affected by the degree of soil water movement. A high rate of water exchange removing dissolved ions means that the archaeological material cannot reach equilibrium with its surrounding environment and will not be preserved. The type of archaeological material will influence the rate of dissolution; for example, many metals may form surface patinas that are more stable in the surrounding soil and prevent or reduce the rate at which dissolution occurs (Edwards 1998; McNeil and Selwyn 2001).

For the purpose of interpreting the degradation rates of the buried samples, the monitoring was expanded as follows at the burial site (Fig. 3). Soil samples were collected from the individual soil horizons at the time of burial for subsequent chemical analysis by Forest Research. A tension lysimeter was installed to directly remove soil solution from three horizons in the burial trench for chemical analysis, as outlined above. Peizometers were installed alongside the burial trench to measure water levels and provide water samples to measure the oxidation-reduction balance (redox potential) of each horizon. A soil moisture profile probe was installed to measure soil moisture content to determine and compare the hydrological regime in the soil horizons. Six standpipe peizometers (dipwells) were installed in augered holes in close proximity to the burial site: three on either side of the trench at depths to correspond with the sample depths (0.1, 0.38, and 0.9 m below the surface). The peizometers comprise standpipe tubes sealed along their length with Casagrande porous plastic tips that allow the ingress of water into the tube. Water levels in the peizometers are measured using a dip-meter probe which is lowered down the standpipe on a calibrated cable and emits an audible signal on contact with the water. Samples of water can be retrieved by means of a bailer to measure redox potential.

The relationship between the condition of excavated archaeological finds and their surrounding soil environment has been studied using mineralogical analytical methods with a view to predicting the aggressiveness of soil types towards metal finds (Gerwin and Baumhauer 2000). However, there are limitations in relying just on archaeological material even if soil samples are taken from the soil immediately surrounding the finds at the time of excavation. The complete history of the find and its burial environment is unknown: the use and condition of finds during their lifetime, the condition of the finds at the point of burial, and the behavior of the burial environment over centuries cannot be accurately gauged and used to comment on the relationship between finds and the burial environment. The use of modern analog samples to represent a range of archaeological materials should allow the collection of controlled baseline data. The information potential of archaeological materials is also an important consideration; the archaeological material may survive but the material is modified to such a degree that archaeological information is lost. It is important to have controlled scientific data to advise archaeological curators at what points the information potential of finds is reduced and lost.

The moisture content of the burial environment is measured using a soil moisture profile probe (Delta-T profile probe) comprising a one meter length probe with six pairs of rings at depths of 0.1, 0.2, 0.3, 0.4, 0.6, and 1 m. Each pair of rings generates an electromagnetic signal into the surrounding soil and the moisture content of the surrounding soil will determine how much of the signal is reflected. The soil moisture content at the six depths is continuously recorded on a data logger connected to the probe. Figure 4 shows the soil moisture data collected for the period of mid- June to August 2005 plotted against precipitation data for the same period. The monitoring data will be assessed in conjunction with the findings from the retrieved analog samples to identify any possible correlation and potential influences on preservation. A comparison will also be made with findings from the mineral burial study at the same site to assess the potential for predicting preservation at other sites.

Geochemical models using soil solution to simulate the reaction paths of minerals can be used to indicate the likelihood of archaeological materials surviving. It can also provide an indication of the types of materials that are not conducive to surviving in the burial environment 64

KARLA GRAHAM AND PETER CROW: A WOODLAND BURIAL STUDY http://www.defra.gov.uk/sustainable/index.htm (accessed February 2010).

and therefore materials that could have been originally present in the archaeological record. The woodlands burial study is one of a number of studies currently combining geochemical modeling and experimental fieldwork using modern analog materials (Pollard et al. 2004).

Department of the Environment. 1990. Planning Policy Guidance Note 16: Archaeology and Planning. London: HMSO. Available at http://www.communities.gov.uk /documents/planningandbuilding/pdf/156777.pdf.

As a feasibility study, the woodlands burial study is intended to assess some options for how we can approach determining the condition of materials within the burial environment, how to use this information to comment on preservation in situ, and what the most appropriate methods are for doing this. It should be applicable to any burial environment, not just to woodland soils.

Durrant, D. 2000. Environmental Monitoring in UK Forests. Forestry Commission Information Note 37. Edinburgh: Forestry Commission. Edwards, R. 1998. The effect of changes in groundwater geochemistry on the survival of buried metal artefacts. In Preserving archaeological remains in situ. Proceedings of the conference of 1st–3rd April 1996, eds. M. Corfield, P. Hinton, T. Nixon, and M. Pollard, 86-93. London: Museum of London Archaeology Service.

Acknowledgements Thanks to Nadia Barsoum, Sue Benham and Elena Vanguelova for permission to use the monitoring site, comments on the trench location and the provision of other site data. Thanks also to Lorraine Adams, Francois Bochereau, Lorna Johnstone, Matt Wilkinson, Matt Williams and Liz Young for the ongoing site monitoring and chemical analysis of samples. Thanks to project team members Vanessa Fell, John Vallender and Roger Wilkes (English Heritage), and Paul Simpson (Isle of Wight County Council). Thanks also to Mark Jones (Mary Rose Archaeological Services Ltd) and Paul Wyeth (Textile Conservation Centre, University of Southampton) for advice on cotton testing.

Forestry Commission. 2005. Keepers of Time: A Statement Policy for England’s Ancient and Native Woodland. Edinburgh: Forestry Commission. Gerwin, W., and R. Baumhauer. 2000. Effect of soil parameters on the corrosion of archaeological metal finds. Geoderma 96: 63-80. Graham, K. 2005. Method for maintaining anoxic conditions for the extracted metal samples. In Equipment for the Installation of Experimental Materials at Fiskerton, Lincolnshire. Center for Archaeology Report 32/2005, ed. V. Fell. London: English Heritage.

Bibliography British Standards Institution. 2002. BS EN 13601:2002 Copper and copper alloys. Copper rod, bar and wire for general electrical purposes. British Standards Institution.

Hall, R. 1996 Hydrological Effects of Short Rotation Coppice. Energy Technology Support Unit Report B/W5/00275. Harwell, UK: Energy Technology Support Unit.

Cassar, M. 2005. Climate change and the historic environment. London: Centre for Sustainable Heritage, University College London.

Loveland, P.J. 1993. The classification of the soils of England and Wales on the basis of mineralogy and weathering. In Critical Loads: Concept and Applications, eds. M. Hornung and R. Skeffington. London: HMSO.

Corfield, M., P. Hinton, T. Nixon, and M. Pollard, eds. 1998. Preserving archaeological remains in situ. Proceedings of the Conference of 1st–3rd April 1996. London: Museum of London Archaeology Service.

McNeil, M., and L. Selwyn. 2001. Electrochemical processes in metallic corrosion. In Handbook of Archaeological Sciences, eds. D. Brothwell and A. Pollard. Chichester: John Wiley and Sons.

Council of Europe. 1992. European Convention on the Protection of the Archaeological Heritage (Revised). European Treaty Series 143. Valletta: Council of Europe. Crow, P., and A. Moffat. 2005. The management of the archaeological resource in UK wooded landscapes. Conservation and Management of Archaeological Sites 7: 103-116.

Murphy, P., and S. Trow. 2004. Coastal change and the historic environment. In Preserving archaeological remains in situ? Proceedings of the 2nd Conference 12– 14 September 2001, ed. T. Nixon. London: Museum of London Archaeology Service.

Department for Environment, Food and Rural Affairs. 2005a. Countryside Stewardship Scheme (CSS). (Redirected to http://www.naturalengland.gov.uk/ ourwork/farming/funding/closedschemes/css/, accessed February 2010). Department for Environment, Food and Rural Affairs. 2005b. Sustainable Development.

Nixon, T., ed. 2004. Preserving archaeological remains in situ? Proceedings of the 2nd Conference 12–14 September 2001. London: Museum of London Archaeology Service. Palma, P. 2004. Final report for the monitoring theme of the MoSS Project. In MoSS Final Report. Monitoring, 65

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Safeguarding and Visualizing North-European Shipwreck Sites: Common European Cultural Heritage – Challenges for Cultural Resource Management, ed. C. Cederlund. Helsinki: The National Board of Antiquities.

Addresses Karla Graham* English Heritage Fort Cumberland Fort Cumberland Road Eastney, Portsmouth PO4 9LD UK

Pollard, A., L. Wilson, A. Wilson, J. Hall, and R. Shiel. 2004. Assessing the influence of agrochemicals on the rate of copper corrosion in the Vadose zone of arable land. Part 1. Field experiments. Conservation and Management of Archaeological Sites 6 (3 & 4): 363-375.

Peter Crow Environment and Human Sciences Division Alice Holt Lodge Wrecclesham Farnham, Surrey GU10 4LH UK

Raiswell, R. 2001. Defining the burial environment. In Handbook of Archaeological Sciences, eds. D. Brothwell and A. Pollard. Chichester: John Wiley and Sons.

*Author to whom correspondence should be addressed.

Shashoua, Y., and S. Thomsen. 1991. A field trial for the use of Ageless in the preservation of rubber in museum collections. In Saving the Twentieth Century: The Conservation of Modern Materials: Proceedings of Symposium 91, ed. D. Grattan. Ottawa, Canada: Canadian Conservation Institute. Tubby, I., and A. Armstrong. 2002. Establishment and Management of Short Rotation Coppice. Forestry Commission Practice Note 7. Edinburgh: Forestry Commission. United States Geological Survey. PhreeqcI – A Graphical User Interface for the Geochemical Computer Program PHREEQC. http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phree qci/ (accessed February 2010). Biographies Karla Graham is an archaeological conservator and Archaeology Commissions project officer within the Research and Standards Department of English Heritage. She received her BA Honors in archaeology and MA in the conservation of historic objects (archaeology) from the University of Durham. She has worked as an archaeologist and archaeological surveyor on developerfunded projects and the English Heritage–funded Monuments at Risk Survey. Her current role includes undertaking research projects related to preservation in situ. Peter Crow is the project leader for the Forestry Commission–funded Historic Environment Research Program. This research examines issues surrounding cultural heritage management in woodland environments, providing advice and guidance to foresters and makers of forest policy. He has a BSc Honors degree in biological science, a MSc in geoarchaeology, and almost 20 years research experience in woodland environments. Further information on this research program can be found at www.forestresearch. gov.uk/heritage.

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EXCAVATING SOIL BLOCKS AT SYLVESTER MANOR Dennis Piechota Abstract In this paper I describe, as first-person narrative, an experiment in applying the conceptual framework of a conservator to the process of archaeological excavation. I consider the standard conservator’s treatment report as an example of a literary format known as transformation narrative and use this to highlight how I, as a representative conservator, selectively use and organize empirical knowledge to understand and explain a complex object. Using a list of my conservation practices I define an approach to the excavation of a soil block taken from a 17th-century plantation site on Long Island, New York. I then present some of my findings and give an overview of the process suggesting along the way that if we see ourselves as engaged in a humanities-based interpretive process as much as a science-based assessment process we can expand our roles as archaeological conservators.

Since the Center has an active program of fieldwork, Edgerton’s question evolved into, ‘What can I as a conservator collaborating with a team of archaeologists bring to field archaeology?’ At first my answers fell within my comfortable role as a technical consultant. But one characteristic of the current field of post-processual archaeology is that it is self-reflective; an archaeologist often considers his identity in relation to his research. So I, too, began to re-examine my role in relation to the Center and archaeological research. I thought of the iconic activity of the conservator, the laboratory conservation treatment, and that of the archaeologist, field excavation, and asked the question, ‘What would the standard methods of excavation look like if they were re-cast from the point of view of the conservator?’ Conservators have a familiarity with the substances of archaeological investigations, and the theoretical developments of the last few decades in both archaeology and conservation have shown that simply acknowledging that one has a point of view can yield significant research insights and avoid common research pitfalls (Berducou 1995; Avrami et al. 2000; Pye 2001; Hodder 2003; Munoz Vinas 2005). So I felt the possibility existed that transferring a new point of view to archaeology from the allied field of conservation may be worth pursuing.

Introduction The late Harold Edgerton, famed inventor and researcher in the uses of the strobe light and side-scan sonar, was also an enthusiastic collaborator on research problems in underwater archaeology and other fields far from his base in electrical engineering. He is known for encouraging many points of view on a problem and for inviting all collaborators with this one challenging question, ‘What do you have to trade?’ (Calcagno 2002). When the archaeologist Claire Calcagno cited this quote at a Massachusetts Institute of Technology (MIT) conference on underwater archaeology in 2002, it struck me as a good question to ask whenever I collaborate: ‘What do I as a conservator bring to the question at hand?’

Conceptual framework I began by examining my own identity as a conservator to see if I could formulate a personal conceptual framework. For me, a conceptual framework is most economically drawn from the set of practices one uses in treatment. I am arguing that the totality of one’s practices will implicitly represent one’s working conceptual framework. Rather than speak in general terms about a conservator’s approach, it is more useful here to list common attributes and then use them as starting points to define a conservator’s approach to excavation. These basic attributes are listed in the left column of the table below (Fig. 1). The right column contains the implications each activity has for excavation.

Over the years in my work on artifact treatments and site consultations, I have served archaeologists as a specialist. The questions I was asked were always wellbounded and technical in nature. In this way my work was framed as a small component within the theoretical and conceptual framework of the archaeologist—one that I was not necessarily aware of. When I was involved in the planning phase of fieldwork, I was invited to the table to help with the anticipated technical problems of field preservation and issues of site chemistry. As such I was like most specialists—a value-added, non-essential member of the team.

The most basic trait is that my treatments are best done in a laboratory setting; this meant that if I were to excavate, a soil block would need to be blocklifted intact and brought to the laboratory. My conservation treatments were usually cast as discrete problem-solving events tailored to the needs of the artifact. This implied that as an excavator I might use non-standard excavation methods which could be different for each soil block. Treatment proceeds deliberately in small increments and over a potentially long time frame. This suggested that micro-stratigraphic excavation should be used and that the process would be relatively slow with respect to fieldwork and include long interruptions to consult the

This changed in 1998 when I took a half-time position at the University of Massachusetts at Boston as conservator for what would become the Fiske Center for Archaeological Research. Steve Mrozowski, director of the Center and its chief archaeologist, said he couldn’t offer a high salary but the position would have equality with the staff archaeologists in all matters. He then encouraged me to feel free to use my time to pursue my own research interests both in the laboratory and in the field. 67

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS

SELECTED CONSERVATION

IMPLICATIONS FOR EXCAVATION

PRACTICES

PRACTICE

Conservation treatment is performed in a laboratory setting.

An intact soil block must be blocklifted from the field.

Treatments are seen as discrete and tailored problem-solving events and not a standardized process.

Non-standard excavation methods may be used as required by the particular soil block.

Work proceeds within a variable and potentially long time frame with pre-treatment analyses and consultations continuing during treatment.

No field season to divide the structure of the study into excavation versus lab processing. Potentially long interruptions in the excavation process to consult with site archaeologists, to examine finds in context.

Recursive assessment is used at the outset to develop a sense of the whole artifact including considerations of its archaeological context, past and current meaning, its current use, and its physical needs.

Multiple points of view and an interdisciplinary approach to understanding the soil block would be used.

Inspection and treatment is done at a characteristically fine scale ranging from naked eye to low-power microscopy to resolve microstructure.

Micro-scale of examination promotes an interest in the micro-artifacts and soil matrix.

Close examination and analysis is done to understand the interplay of natural and cultural causes for an artifact’s condition.

Site formation processes are focused on to understand cultural and natural transformations of the sample.

Improvements in treatment are often reached through the transfer of technologies and methods from other fields.

Experimental methods and materials for excavating, testing, and documenting are promoted.

A well-developed documentation regime is used that includes before, during, and after photodocumentation under different light sources.

Excavation would include detailed photodocumentation.

Figure 1: Table of common conservation practices and how they may translate into excavation practices.

TRANSFORMATION NARRATIVE

TREATMENT REPORT

EXAMPLE

Equilibrium at outset

Idealized artifact data (artifact type and materials of construction)

Key, ferrous, wrought, 17th century

Disruption

Assessment of current condition

Soiled, corroded due to burial

Recognition

Results of observations tests and analyses

X-ray shows continuous metal core with dense corrosion crust

Repair

Treatment plan

Tannic acid treatment followed by surface coating

Reinstatement of equilibrium

Completion of treatment and recommended care

Avoid high relative humidity, handle with gloves

Figure 2: Table showing how conservation treatment reports may be viewed as transformation narratives.

site formation processes would be a natural focus. The conservator often incorporates technologies transferred from other fields to refine his treatment. As an excavator this suggested that I should make use of experimental methods and materials. Finally, the conservator uses a well-developed documentation regime in treatment including photodocumentation. This too would be transferred to the excavation process and explored. Although I have listed the excavation practices as though they are obvious implications of my conservation practices, I want to make clear that these were not apparent at the outset of my work. The implications developed over time during the assessment period of the soil block.

literature and staff archaeologists. The pre-treatment examination period of a conservator uses a kind of recursive assessment where observations are made, refined, and refined again through intimate contact with the artifact. This encouraged multiple points of view and an interdisciplinary approach to understanding the soil block. The conservator typically uses a fine scale of observation in treatment from the naked eye to lowpowered magnification to resolve the microstructure of the artifact. This meant that during excavation I might focus on the soil matrix of the block and the microartifacts it contains. The conservator continually parses natural versus cultural causes for the condition of an artifact; transferring this trait to excavation meant that

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DENNIS PIECHOTA: EXCAVATING SOIL BLOCKS AT SYLVESTER MANOR fiction writings, in high and low literary forms from limericks to historical treatises.

Post-processual archaeology, in addition to being selfreflective, also supports a plurality of approaches. This climate allowed me to preserve the pre-excavation exploration phase in my excavation similar to that a conservator goes through when assessing artifacts prior to treatment. In other words, I did not have specific research questions when I took the soil block. As a conservator I have never been disappointed by an artifact’s ability to teach if I maintained an open mind and took the time to learn. I recognize that no matter how open-minded one tries to be, visual examination is a subjective and selective process. Nonetheless, conservators have a characteristic recursive way of looking at artifacts that incorporates several reexaminations of the artifact to question previous impressions and incorporate new perspectives drawn from experience with similar materials. I hoped that simply situating the excavation process within a conservator’s conceptual framework would be an important experiment whose implications for archaeology would evolve as the ‘treatment’ proceeded.

We can expect the structure of our treatment reports to mirror the framework we use to approach new artifacts as well as being the standard form for describing completed work. Treatment report structure can therefore be used to understand how we organize and make sense of artifacts. It also shows how the non-empirical portion of our conceptual framework is organized; how conservators make the leap from the empirical data gathered during the assessment of an artifact to the final treatment plan. A five-part structure is found in both conservation treatment reports and the genre of transformation narratives. Branigan (1992) cites the linguist Tzvetan Todorov (1971) who described the transformation narrative as composed of the following: 12345-

There is a final characteristic of the conservator’s conceptual framework that I’d like to explain in more detail than the above list of practices allows because I am not sure how widely accepted it is. When I first entered conservation in 1970, I saw myself as a kind of engineer applying science directly to solve practical problems. I believe this view was common in America then and was best expressed in a short article by Sheldon Keck, entitled ‘Training for Engineers in Conservation’ (Keck 1963). Since then, I have noticed that even though we rely on the findings of the hard sciences to develop treatments, we must often apply these findings without the sanction of science. The physico-chemical complexity of archaeological artifacts means that while we can appeal to say, materials science, for authority, we are often on our own when we use science to formulate treatment plans. Given this, I have gradually changed to viewing archaeological conservators as artifact storytellers whose narratives explain and defend their treatment decisions. While this view of the conservator as storyteller may not be common, some archaeologists have cast their actions in just this way. Ian Hodder wrote of the role of narrative in the history of archaeology and used site reports as a reflection of the archaeologist’s conceptual framework (Hodder 1989). Rosemary Joyce writing in The Languages of Archaeology characterized the field as ‘a discipline engaging in the present in the construction of persuasive stories about imagined pasts’ (Joyce 2002) and used literary theory to analyze the nature of archaeological texts.

a statement of equilibrium at the outset; a disruption of the equilibrium by some action; a recognition of the disruption; an attempt to repair the disruption; a reinstatment of equilibrium.

Figure 2 shows how this structure is expressed in our treatment reports. So if you agree that the structure of the treatment report can be used to represent our conceptual approach to artifact conservation, then you might also agree that our approach is in part based on the longstanding literary tradition of transformation narratives. This humanitiesbased view of our treatment decision process situates the empirical scientific core as part of a larger literary structure of argumentation and explanation. Beyond the reach of materials science we routinely construct a sort of physico-chemical artifact history to justify a stabilization treatment. Because of the risks and uncertainty of conservation treatments we embed our empirical observations within a traditional narrative format that has proven successful in fiction and nonfiction at dealing with causality and change. Looking at our work this way also allows us space to recognize the role of the conservator as an interpreter of artifacts. It is this portion of our decision-making process and not the empirical core, that holds promise for the expansion of the conservator’s role as a mediator or liaison bringing together the competing interests of various end-users of archaeological heritage. To return to ‘Doc’ Edgerton’s question, this is what I as a conservator saw myself as having to trade as I considered crossing over into the domain of the archaeologist.

Following Hodder’s analysis of site reports as a form of literature, I looked at the conservator’s treatment report. While reading a text on narrative structure in film (Branigan 1992), I was struck by a parallel between the structure of the treatment report and that of a traditional narrative format called the ‘transformation narrative’. This is a common format used to make sense of complex causality and change. It is found in both fiction and non-

Sylvester Manor In 2003, I applied this approach for the first time to Sylvester Manor, a site that the Center had been excavating for five years. Sylvester Manor is located on Shelter Island at the eastern end of Long Island, New York (Fig. 3). A soil block was lifted intact from a buried

69

THE CONSER RVATION OF ARCHAEOLOGIC R CAL MATERIAL LS: CURRENT TRENDS AND FUTURE F DIREC CTIONS sheet middenn at the site; the t midden deeposit was choosen because it is an extensivelyy excavated feeature.

nor. It is not a continuous deposit and shows laterall man faciies changes and a pinching out of stratiigraphic unitss acro oss the featuree. The soil block under stu udy was takenn from m the south central c sectionn of the middeen (Fig 4 andd 5). Fielld retrieval After building a reuseable bloocklift contain ner, I removedd a so oil block meassuring 40 cm ddeep by 50 cm m wide and 655 cm high from thee field. I usedd a design for the containerr thatt was derived from my experience as a a museum m packer. Called a ‘knock-downn case’, it disaassembles intoo six sides (Fig. 6)). With the heelp of the field crew, I wass ablee to drive thee case bottom m under the soil block andd then n assemble the case aroundd it (Fig. 7). The T size of thee soill block was limited by thee maximum weight w of soill thatt could be haandled and trransported wiithout speciall equ uipment; this corresponded c to a volume of o 0.13 m3 andd a weight w of approoximately 8000 pounds. Thee height of 655 cm allows compplete profiles to be retrieveed from mostt areaas of Sylveester Manor. The length h and widthh dim mensions weree selected as m minimums thaat would leavee the largest artifaccts undisturbedd.

Figure 3: Mapp of Long Islandd, New York shhowing the location of Shelter Islannd.

It is the sitee of a 17th-ceentury provisiioning plantattion. For a short time a comm munity was formed, f incluuding African slaves and Native American laborers, l worrking under the direction of European E oveerseers to furrnish provisions for fo themselves and for ann affiliated sugar plantation onn the island off Barbados.

Figure 4: Souuth Lawn area of Sylvester Manor M showingg the location of thee midden and the t area from which w the soil block b was retrieved Figu ure 6: Disassem mbled six-sided soil block case.

Figure 5: Soil block in situ shhowing its nortth face, the possition of the buried midden and a filled posthoole in the northheast corner.

The manor is i situated on the shore off a protected inlet allowing a shallow wateer site for looading Barbaadosbound shipm ments and from which the large amounnt of coral we enncounter in thhe midden was w off-loadedd as ballast. The buried middeen layer underr study coverrs an area of moree or less 40 m2 on the Soouth Lawn off the

Figu ure 7: Soil blockk being encasedd in the field.

70

DENNIS PIECHOTA: EXCAVATING SOIL BLOCKS AT SYLVESTER MANOR channels partially and completely filled with loamy sediment. Isolated artifacts including a pipe stem and a butchered bone fragment are seen at the bottom of the mottled layer under the relatively loamy center section of that layer. The B layer is clay-bearing glacial till showing reduced porosity compared with the upper layers.

In the lab I built a cradle that would hold the case and soil block at a 45º angle to provide stable plan and profile excavation surfaces. I fitted the cradle for microscopy and added two longwave (365 nm) ultraviolet lamps for fluorescence imaging (Fig. 8).

Figure 9: Profile A-A’ of soil block under visible light

Figure 8: Soil block showing the south profile of the soil block positioned within a wood cradle at a 45º angle and fitted for low-power microscopy with LED lighting, incandescent lighting, and two longwave fluorescent lamps. Figure 10: Longwave (365 nm) UV autofluorescence image of soil block profile B-B’ showing the layering of the midden.

Initial assessment After a period of examining the effect of the living soil fauna on soil structure (the soil block unexpectedly turned into a kind of archaeological terrarium), I removed the duff layer from the plan surface and about 3 cm of disturbed profile surface from its north face.

During the assessment period and initial excavation, I familiarized myself with the literature of several fields that bear on site formation processes including microartifact patterning and earthworm studies. I began taking courses at Boston University in micromorphology and geoarchaeology with Dr. Paul Goldberg and corresponded with Dr. Art DeGaetano at Cornell University on soil freeze/thaw mechanics. I also began experimenting with the ultraviolet fluorescent imaging of soil surfaces.

Viewing it in profile I saw that the soil block was composed of at least four strata (Fig. 9). The top landscape layer (A1) is 25–30 cm thick and composed of sandy loam. This layer was applied around 1750 and covers the entire midden. The midden layers (A2) are approximately 10 cm thick and include at least two depositional events separated by a layer of earthworm cast soil about 5 cm thick. This two-part layering became more apparent later when I viewed a second profile under longwave ultraviolet light (Fig. 10).

Micro-artifact distribution Space does not allow me to present my work on this soil block in detail (Fig. 11). Instead I will present an overview of the process and selected areas of study. For a more detailed discussion please see Piechota (2007).

The upper midden layer is dominated by shell and bone. Below that is a richly organic earthworm cast layer, which shows good preservation, including the porous, nodular structure similar to fresh earthworm casts. The bottom layer of the midden is dominated by coral fragments of a type found on Barbados. The midden deposits rest on about 20 cm of mottled or bioturbated soil (A/B) showing earthworm tubes and decayed root

After I examined the profile surface closely under lowpowered magnification, I selected the mottled layer as a point of interest because of the large number of microartifacts visible in it. These small artifacts appeared to be created largely by frost damage and then redistributed downward into the soil as a result of the short but intense 71

THE CONSER RVATION OF ARCHAEOLOGIC R CAL MATERIAL LS: CURRENT TRENDS AND FUTURE F DIREC CTIONS period of earrthworm and root r bioturbatiion of the middden layers.

ggested that within a particuular disturbed soil matrix, a sug chaaracteristic disstribution patttern of these particles mayy dev velop over tim me. The shappes of these distributionss cou uld be used to indicate the relative age of o the originall dep posit as well as a the duratioon of the actiive depositionn periiod (Fig. 12).

Figure 11: Topics T investigated during thhe assessment and excavation of the t soil block.

Figu ure 12: Effeccts of bioturbbation and grravity on thee arch haeological reecord. A: siingle-componen nt or recentt asseemblage in mootion; B: mullti-component assemblage orr depo osit of long duration in m motion; C: sin ngle-componentt asseemblage or anccient deposit settling (adapted d from Michiee 1990).

I thought off the mottled layer as a product p of huuman intervention on the landsccape. Earthworms are know wn to be sensitive to low soil pH H (Stein 19833; Edwards 19996) and are unabble to flourishh in the naturral soil of Shelter Island whichh has a pH range of 4.0 to 4.5 (Warner 19975). When the first f layer off coral was deposited in the midden, perhhaps in 1660, this caused a dramatic incrrease in the earthhworm populaation by raising the soil pH. Climate studdies predict that t freeze/thhaw effects are a a surface pheenomenon inn this part of the world w (DeGaetano et al. 1996).. When the landscaping l l layer was applied in 1750, thee rate at whicch micro-artiffacts were produceed by frost daamage fell offf dramaticallyy. So the mottled layer was larrgely produceed over 90 years y from 1660 too 1750 by the actions a of hum mans.

Forr my work I plotted p particles visible on n the exposedd profiles by recorrding their loccation onto a sheet of glasss placced over the profile. p I seleccted charred wood w particless to represent thee downward movement of o an ancientt dep posit. There is no charcoal inn this part of the t midden soo I reeasoned that any charcoal in mottled layer l resultedd from m forest firees and otheer causes occcurring overr thou usands of years (Collins 19990; Skjemstad d et al. 2002).. To test the pattterning of reecent depositts, I selectedd several materialss visible in thhe midden laayer includingg coraal, bone, morttar, shell, andd redwares. I decided d to usee ultrraviolet light to record tthe group of o fluorescentt matterials—coral,, shell, bonee, and mortaar—that weree visiible in the middden layers. I used visible light l to recordd the position of thhe redwares annd charcoal individually.

The rate at which w particlees descend thhrough the sooil is significant too understandiing the age of a deposit and whether it iss primary or secondary. It is possible that parts of the midden m were originally o depoosited as a moound and then sprread out just before that landscaping l l loam was applied.. Such seconddary spreadinng of the middden could lead too an inversion in the temporral strata in which w older depositts are spread out o on top of younger depoosits. If so, I reassoned that thhe descent paatterns of miicroartifacts from m the spread out o deposit would be relatiively shallow comppared to the primary p layer.

Thee particles weere then counnted and grou uped by depthh belo ow the middeen to produce a seriation graph. g I foundd thatt this test of profile p mappinng was usefull in that it didd pred dict graphs that t fit with Michie’s. I was able too iden ntify the charcoal as an anncient micro-aartifact patternn verssus the fluoreescent particlee group which h is known too deriive from the 350-year-old 3 m midden.

I also wonddered whetheer direct observation of the profiles coulld be used to record this patterning. p Miicroartifact distrributions havve been anaalyzed by other o researchers using u the moore labor inteensive processs of grain-size annalysis, where micro-artifaccts are collecteed in specific size ranges by siieving the soiil from excavvated strata (Michiie 1990; Sherw wood 2001; Leigh L 2003). I felt that direct obbservation, if accurate, wouuld be much more m efficient andd could be deeveloped as a field technnique using a simpple binocular viewer v and caarefully excavvated profiles.

Furrther work is being b done noow to confirm m the accuracyy of the t method byy collecting annd counting micro-artifacts m s from m each excavvated 1-cm laayer. My focu us now is onn seeiing if the methhod can be ussed to discriminate betweenn receent deposits and a to addresss whether it can be used inn the field to determine whetheer parts of th he midden aree prim mary or seconndary deposits. n Exccavation plan Thee soil block exxcavation had four phases. I took verticall slices of the soil block to creatte repeated su urfaces for thee partticle mappingg. At the sam me time, I starrted removingg the landscaping layer in fouur 5-cm leveels. This wass followed by excaavation of the midden and mottled m layerss as a series of tweenty-three 1-ccm levels. Finaally the densee B laayer was excaavated at 2-cm m intervals (Fig g. 13).

Michie (19900) has shown that t one can plot p the downw ward movement of micro-artifaacts as a funcction of time and a a seriation graph of miicrodisplay that movement as artifact freqquencies agaiinst depth in i the soil. He 72

DENNIS E PIECHOTTA: EXCAVATIING SOIL BLOC CKS AT SYLVE ESTER MANOR R

Figure 14: Plann for soil blockk excavation.

As a trial, I seleccted coumarinn-1, a dye class which givess perssistent fluorescence whenn in contact with w a broadd rang ge of amino acids. Beforee applying thee chemical too the soil block, the techniquee was first developed d onn prep pared soil saamples. The ssurface of a test soil wass prettreated with drops d of very dilute aqueou us solutions off gelaatin, from 0.1% down to 0.025% % w/v. Thee flurrochrome, marketed m ass Polyfluor YG® byy Poly ysciences Incc., was applieed to the treated surface. I foun nd that when the coumarinn was prepared d as a 0.125% % w/v v solution in ethyl e alcohol and eyedropp ped across thee gelaatin test areaas, it fluoressced brightly whenever itt encountered gelaatin in the soil (Fig. 14).

Fluorescent tagging In addition too the micro-arrtifact study, I looked at sevveral other aspectss of the soil block. I willl mention onne of these studiees here. As a routinee documentaation procedure, I had been exxamining the soil block under u longwave ultraviolet lightt. Some highhly UV absorb rbing areas were noted in thee midden laayer and seeemed associated with w the burieed faunal rem mains, suggessting that very deggraded proteinn residues maay still be pressent. So a novel method m of prrospecting forr protein residdues was incorpoorated into the t excavatioon process. This method usess a chemicaal protein taggging agent that fluoresces under u longwaave UV in the presencee of proteins. It iss possible to induce ultraviolet fluoresceence chemically too highlight sellected classes of materials. Soil scientists havve applied fluuorescent tagging agents (also ( known as fluuorochromes) to soil surfacces and soil water w to study perrcolation pattterns and traansport proceesses (Vanderborghht 2002). DN NA researcherrs routinely appply fluorescent taagging agents to proteins too isolate particcular amino acids.. I decided too test whetheer a fluorochrrome would highhlight the residues of o proteinaceeous degradation products on o excavatedd surfaces. The likelihood off preservationn of such perrishable mateerials was low givven the soil coonditions. Buut past experieence had shown that minor quantities off perishables can persist in isollated pockets under the worrst conditions.

Figu ure 14: Test of Polyfluor YG G® (coumarin--1). Loam wass inocculated with different concenntrations of geelatin and thenn Poly yfluor YG waas applied as a 0.125% solu ution (w/v) inn ethaanol by eye dropping. d Whitte areas show reaction withh gelaatin. Gray areass are backgrounnd fluorescencee. Photographedd under longwave (365 nm) ultravioolet light.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS conservator’s approach to treatment that he incorporates new technologies in his treatment plan. My work with the ultraviolet dye coumarin-1, while preliminary, is promising and would be accessible to most archaeological processing laboratories. By bringing the excavation process into the laboratory, one can freely associate developing technologies with archaeological investigation.

With this technique, the soil block was periodically sprayed with the fluorochrome solution, and one positive response was detected under a butchered sheep’s scapula (Fig. 15).

I have written this paper in the first person. I chose this point of view in an attempt to reposition myself with respect to my past as a conservation specialist. Conservation is as personal as it is scientific and I saw first-person narrative as the easiest way to emphasize this and perhaps separate myself from what has been called ‘classical conservation’ (Munoz Vinas 2005:66). There is a developing tradition in conservation that recognizes that the scientific phase of our work is embedded in a larger humanities-based tradition. I have argued that our treatment reports are essentially transformation narratives—a form of science-based storytelling. This was brought home to me recently while treating some of the iron artifacts found at Sylvester Manor. When my director Steve Mrozowski saw how the formless rusting hulks were being transformed into recognizable implements, he exclaimed, ‘Dennis, you’re making data!’ I must have looked concerned at this characterization of conservation because he quickly added that that was a good thing. And I realized the degree to which a treatment that I saw as primarily stabilization was an interpretive action that transformed the artifact’s archaeological meaning.

Figure 15: Fluorescent protein-bearing soil surface (gray area) under a sheep’s scapula just under the midden layer of the soil block. Photographed with longwave ultraviolet light after spray application of the fluorochrome Polyfluor YG® to the soil.

I sampled the fluorescent soil and submitted it to a simple microchemical test, the xanthoproteic test, for protein. It proved positive and I am now investigating whether the proteins present can be shown to be derived from the butchered sheep bone. While this investigation is still ongoing, it suggests that a variant of this method may prove useful in the field as well as in the laboratory as a quick and inexpensive way to locate and record the position of protein residues.

So I’ve used the narrative format in this paper to distance myself from presenting a conservator’s actions as solely based on scientific data. Whether engaged in treatment or in excavation, our identities compel us to select and develop in a subjective way the empirical data before us. I hope that recognizing this will not undercut our rigor but will in fact allow us to expand our role in archaeology from specialists to equal collaborators.

Future work I have just completed excavating the last 2 cm of the soil block. The micro-artifacts sieved from the 1-cm excavation levels are still being counted and the micromorphological thin sections are still being analyzed, so I cannot yet synthesize the information I have gained. Nonetheless, this experiment in excavation has proved successful enough that I have retrieved a second soil block from Sylvester Manor. This one comes from an area of the site that contains a Native American habitation. It promises to be a very different excavation process and I will report on it in the future.

Bibliography Avrami, E., R. Mason, and M. de la Torre. 2000. Values and Heritage Conservation. Los Angeles: The Getty Conservation Institute. Berducou, M. 1995. Introduction to archaeological conservation. In Historical and Philosophical Issues in the Conservation of Cultural Heritage, eds. N.S. Price, M.K. Talley, and A.M. Vaccaro, 248-259. Los Angeles: The Getty Conservation Institute.

Conclusion Looking back over my work I feel that the use of a conservator’s approach to excavation by placing a soil block in a laboratory setting provides an opportunity to do basic and applied research, and to evaluate novel technologies and new field methods. In this way one creates an experimental platform for the development of the excavation process itself. The development of methods to directly observe the post-depositional movement of micro-artifacts is one example of the experimental potential of soil block research.

Branigan, E. 1992. Narrative Comprehension and Film. London: Routledge. Calcagno, C. 2002. Edgerton’s gifts: MIT at the dawn of underwater archaeology. 2nd MIT Conference on Technology, Archaeology, and the Deep Sea: April 2628, 2002. Cambridge, MA: Massachusetts Institute of Technology.

We live in a world rich with rapidly developing lowtechnology tools and it is characteristic of the 74

DENNIS PIECHOTA: EXCAVATING SOIL BLOCKS AT SYLVESTER MANOR Todorov, T. 1971. The two principles of narrative. Diacritics 1: 37-44.

Collins, S.L. 1990. Introduction: fire as a natural disturbance in tallgrass prairie ecosystems. In Fire in North American Tallgrass Prairies, eds. S.L. Collins and L. Wallace, 3-7. Norman, OK: University of Oklahoma Press.

Vanderborght, J. 2002. Imaging fluorescent dye concentrations on soil surfaces: uncertainty of concentration estimates. Journal of the American Soil Science Society 66: 760-773.

DeGaetano, A., D. Wilks, and M. McKay. 1996. Atlas of Soil Freezing Depth Extremes for the Northeastern United States. Ithaca, NY: National Regional Climate Center. Edwards, C.A. 1996. Biology and Earthworms. London: Chapman & Hall.

Ecology

Warner, J.W. 1975. Soil Survey of Suffolk County, New York. Washington, DC: USDA Soil Conservation Service.

of Biography Dennis Piechota is the archaeological conservator of the Fiske Center for Archaeological Research at the University of Massachusetts at Boston, where he conserves finds from the Center’s terrestrial archaeological sites and conducts research in micromorphology, micro-excavation and elemental analysis of artifacts and the soil matrix. He is also part of the adjunct faculty of the Institute for Archaeological Oceanography, University of Rhode Island, where he conducts research on deep water archaeological preservation.

Hodder, I. 1989. Writing archaeology: site reports in context. Antiquity 63: 268-274. Hodder, I. 2003. Reading the Past. Cambridge: Cambridge University Press. Joyce, R. 2002. The Languages of Archaeology. Oxford: Blackwell. Keck, S. 1963. Training for engineers in conservation. In Recent Advances in Conservation, ed. G. Thomson, 199201. London: Butterworths.

Address Archaeological Conservator Fiske Center for Archaeological Research University of Massachusetts at Boston 100 Morrissey Blvd. Boston, MA 02125-3393 USA

Leigh, D. 2003. Buried artifacts in sandy soils. In Earth Sciences and Archaeology, eds. P. Goldberg, V. Holliday, and C. Ferring, 269-293. New York: Kluwer Academic/Plenum Publishers. Michie, J. 1990. Bioturbation and gravity as a potential site formation process: the open area site, 38GE261, Georgetown County, South Carolina. South Carolina Antiquities 22(1): 27-46. Munoz Vinas, S. 2005. Contemporary Theory of Conservation. Amsterdam: Elsevier. Piechota, D. 2007. The laboratory excavation of a soil block from Sylvester Manor. In The Archaeology of Sylvester Manor, Special Issue Northeast Historical Archaeology 36: 83-99. Pye, E. 2001. Caring for the Past. London: James and James. Sherwood, S.C. 2001. Microartifacts. In Earth Sciences and Archaeology, eds. P. Goldberg, V. Holliday, and C. Ferring, 327-351. New York: Kluwer Academic/Plenum Publishers. Skjemstad, J., D. Reicosky, A. Wilts, and J. McGowan. 2002. Charcoal carbon in U.S. agricultural soils. Journal of the Soil Science Society of America 66: 1249-1255. Stein, J. 1983. Earthworm activity: a source of potential disturbance of archaeological sediments. American Antiquity 48(2): 277-289.

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THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE OF ARCHAEOLOGICAL FINDS Sanchita Balachandran Abstract In the work of the University of Pennsylvania MuseumYale University-Institute of Fine Arts New York University Expedition to Abydos, Egypt, cyclododecane, a sublimating wax with a low melting point, has been used with great success in the temporary stabilization, lifting, long-term storage, and reburial of artifacts. Nearly 1000 objects were excavated, examined, conserved, and/or packed for storage by the site conservators during the 2002-2003 and 2004-2005 seasons, with several requiring treatment with cyclododecane. This versatile conservation material allowed for the preservation of fragile artifacts that often do not survive excavation, storage, or reburial. Citing specific examples, this paper discusses some of the applications of cyclododecane during the two field seasons. The paper also comments on how the use of cyclododecane in the excavation of important finds resulted in increased trust between the conservators and archaeologists, and facilitated regular collaboration on site.

These are widespread and difficult ethical dilemmas faced by any excavation, and they are best addressed through collaborations between archaeologists, conservators, and other specialists. For conservators, these decisions are particularly problematic given the emphasis in our professional standards and training on the importance of preserving all material of cultural importance.1 Many conservators are trained in museum contexts where materials of lesser research interest or with complicated conservation problems may simply be stored away and left untreated; however, on an archaeological excavation, such materials may be in fact be lost forever. The challenge of preserving as much of the archaeological record as possible is further complicated by limited time and resources, as well as by the competing priorities of various researchers on site. This paper concerns the 2002-2003 and 2004-2005 seasons of the University of Pennsylvania Museum-Yale University-Institute of Fine Arts New York University (hereafter, Pennsylvania-Yale-Institute of Fine Arts NYU) Expedition to Abydos, where a concerted collaborative effort by conservators and archaeologists maintains effective and ethical archaeological practice. The conservation strategy at Abydos is to maximize the preservation of archaeological finds—an approach that has been viable in large part because of the use of the volatile temporary consolidant, cyclododecane. Utilized primarily in lifting extremely fragile and structurally unstable objects from the field, cyclododecane has ensured the preservation of many finds which would not have otherwise survived excavation. The following sections present the specific applications of cyclododecane at Abydos, and emphasize how this material offers alternative approaches to long-standing dilemmas faced by archaeologists and conservators in the field.

Introduction ‘The preservation of the objects that are found is a necessary duty of the finder. To disclose things only to destroy them when a more skillful or patient worker might have added them to the world’s treasures is a hideous fault’ (Petrie 1904:85). So Flinders Petrie, fresh from seasons in the field at Abydos, Egypt, wrote in his influential book Methods and Aims in Archaeology. More than 100 years later, most archaeologists and conservators would readily agree with Petrie’s statement. However, the reality of any archaeological excavation is that it is an inherently destructive process in which all of the materials exposed cannot be treated with equal importance. It is unavoidable that some materials will be preserved at the cost of others, and it is archaeologists and conservators who are called upon to make the difficult decisions about what to remove, what to rebury, and what is beyond preservation. For example: • On any given archaeological level, there are several finds in equal need of conservation attention; which find’s preservation takes precedence over the others? • An object of important archaeological value cannot be lifted from the field for various reasons. Other objects are excavated through or reburied. What responsibilities do we have toward finds we rebury? What are our responsibilities to future excavators? • An object can be lifted from the field but may never be reconstructed. Is it more important to attempt to retrieve the object, or to simply document it and leave it to be reburied?

Introduction to the site Abydos, located 90 miles north of Luxor, was one of Egypt’s most important centers from nearly 4000 BC until the 7th century AD. All of the kings of the First Dynasty and two of the Second Dynasty were buried in underground tombs at Umm el-Qa’ab at another section of the site, and funerary enclosures associated with these rulers were built in the area now known as the Abydos North Cemetery. The most visible structure at the Abydos North Cemetery is the Shunet-el-Zebib, dated to the reign of King Khasekhemwy (c. 2750 BC); this impressive monument stands eleven meters high in 1

The American Institute for Conservation of Historic and Artistic Works (AIC) Code of Ethics identifies cultural heritage as ‘material which has significance that may be artistic, historical, scientific, religious, or social’ and places the responsibility of preserving this heritage on the conservator (AIC 1994).

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS places, and covers over 10,000 square meters. Abydos continued its importance as a funerary site and administrative center throughout the Old Kingdom, and became the cult center for the worship of Osiris in the Middle Kingdom. An important New Kingdom temple built by Seti I is also located here. In the Roman/Byzantine (‘Coptic’) period, Coptic monks carved cells and other structures into the massive walls of the Shunet-el-Zebib.

Abydos in the 2002-2003 season, and again in 20042005. During these two seasons, there were at most two trained conservators on site, including the author.3 Given the large scale of the excavations, conservators had many different responsibilities; our main priorities were to identify and treat finds as required, to assist archaeologists in the excavation of particularly fragile finds or to consult on materials in the field, and to pack the more vulnerable and important objects for storage.

Abydos has been of keen interest to foreign excavators since the 19th century. Auguste Mariette was the first to excavate here from 1858 to the 1860s, followed by Émile Amélineau (1895–1899) and Flinders Petrie (1899– 1903), among others. Since the mid-1960s, the northern part of the vast site of Abydos has been the focus of the work of the University of Pennsylvania Museum-Yale University Expedition under the co-directorship of Dr. David O’Connor and Dr. William Kelly Simpson. The Institute of Fine Arts (IFA), New York University (NYU), joined the expedition as a co-sponsor in 1995. This paper concerns excavation work carried out in the 2002-2003 and 2004-2005 seasons of the North Abydos Project, which functions under the aegis of the Pennsylvania-Yale-Institute of Fine Arts NYU Expedition, and is directed by Dr. David O’Connor and Dr. Matthew Adams, both of the IFA. The project’s operations are carried out under the field direction of Dr. Adams, with an important component of the 2004-2005 season’s work supervised by Laurel Bestock, also of the IFA. During these seasons, enclosures and subsidiary graves associated with King Aha of the First Dynasty (c. 3050 BC) were investigated.

Abydos is an extremely rich archaeological site, and peak excavation periods resulted in the daily discovery of many artifacts. Past seasons have yielded a broad range of materials including limestone, alabaster, ceramics, faience, unfired clay, painted plaster, wood, ivory, leather, cloth, plant fiber, and matting. Though sand and soil conditions vary throughout the site, in general, most finds are remarkably well preserved when first exposed; however, conditions on site such as extreme heat, strong wind, and cycling humidity drastically affect their stability. Therefore, objects once exposed and documented require rapid retrieval in order to ensure their preservation. One of the most challenging and rewarding aspects of working at Abydos is the extent to which conservators work with archaeologists in the field to lift such fragile finds; in these instances when time is extremely limited, traditional conservation materials and methods (such as consolidating with an acrylic resin or emulsion and facing with Japanese tissue) are often too slow, or labor intensive. Other common techniques, such as block-lifting objects using the surrounding soil as support, are inappropriate at Abydos as the finds are often in loose sand or soil. In cases where finds are so structurally unsound that more familiar conservation methods are inappropriate, and when the speed of retrieval is critical both for the preservation of the object and for the continuation of the excavation, cyclododecane offers an immediate, stable, and truly reversible treatment option.

Conservation at Abydos Conservators have been periodically involved at Abydos since the start of the Pennsylvania-Yale-Institute of Fine Arts NYU Expedition’s work at the site. Conservation staff members have been a regular part of operations since spring 2000 when Lawrence Becker and Deborah Schorsch were involved in a specific campaign to investigate and retrieve portions of one of fourteen boats found buried adjacent to the Shunet-el-Zebib.2 This work was part of a program of activities carried out with the support of the Egyptian Antiquities Project (EAP) of the American Research Center in Egypt (ARCE), with funding provided by the United States Agency for International Development (USAID). Another aspect of this program is the ongoing extensive conservation of the Shunet-el-Zebib under the supervision of preservation architects Anthony Crosby and William Remsen.

Cyclododecane: material characteristics Both natural and synthetic waxes have a long history of use in field conservation in Egypt. Petrie mentions the use of molten paraffin and beeswax, as well as ‘wax dissolved in benzol’ to stabilize limestone, wood, painted stucco, and ivory (Petrie 1904: 86). He writes of treating ‘the great stuccoed sarcophagus at Hawara...by heating the surface with a wire dish of charcoal burning about six inches above it, and flooding the surface with melted wax so soon as it was enough heated to absorb it’ (Petrie 1904: 90). Alfred Lucas, Egyptologist and chemist, recommended the use of hot wax on fragile artifacts, suggesting that ‘wax could…be applied with a pipette or brush or, for large objects, poured from a can or teapot’ (Gänsicke et al. 2003a: 183). Both Petrie and Lucas would have known of the work of Friedrich Rathgen, Director of the Chemical Laboratory of the Royal

Becker and Schorsch pioneered the use of cyclododecane to stabilize structurally compromised wood planks during both the excavation process and subsequent storage. Due to the success of this joint effort, conservators were invited to join the excavation staff at 2 Lawrence Becker is Sherman Fairchild Conservator in Charge of the Department of Objects Conservation at the Metropolitan Museum of Art, New York. Deborah Schorsch is a conservator in the Department of Objects Conservation at the Metropolitan Museum of Art.

3 Deborah Schorsch was on site for the first half of the 2002 season. Mark Benford Abbe joined the excavation for the first half of the 2004 season.

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SANCHITA BALACHANDRAN: THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE Museums of Berlin, whose early publications included a description of the use of molten paraffin wax to stabilize Egyptian metal objects (Gilberg 1987).

these three films types, the dense, tightly packed film produced from a melt is agreed to be the most resistant to mechanical stress and the most hydrophobic, but also the slowest to sublime. Some studies have also examined the extent to which cyclododecane penetrates into the pores of various materials (Riedl and Hilbert 1998; Stein et al. 2000; Muros and Hirx 2004). It appears that cyclododecane in solution generally penetrates furthest into substrates, except in cases where molten cyclododecane is applied to a pre-warmed surface.

Wax had the benefit of quickly strengthening objects for transport and immobilizing loose and delicate fragments in place, but it also came with significant disadvantages. The impregnation of objects with wax was not a reversible treatment, as it could never be completely removed; this was particularly problematic in situations where wax had saturated or obscured details in artifacts. Different waxes also tended to discolor, oxidize, grow mold, soften or harden in varying ambient conditions, and attract dust and dirt. Most troubling for conservators was the fact that surfaces stabilized with wax could not be re-treated with other conservation materials. Due to these less than ideal material characteristics, wax is no longer used for surface consolidation.

For conservators, the true reversibility of cyclododecane through sublimation is perhaps its most remarkable and attractive characteristic. Several researchers have considered the factors affecting the sublimation rate of cyclododecane from an object’s surface (Hiby 1997; Riedl and Hilbert 1998; Hangleiter 2000; Stein et al. 2000; Nichols and Mustalish 2002; Muros and Hirx 2004). This rate is determined by the application method, i.e., thickness of the film and depth of penetration of the cyclododecane, as well as ambient conditions such as ventilation and heat. Increased airflow over a surface consolidated with cyclododecane will increase the sublimation rate, as will raising the temperature within particular ranges.5 Observations at Abydos suggest that sublimation of cyclododecane from an object’s surface can take anywhere from two days to several months. Conversely, the sublimation of cyclododecane can be prevented, or significantly slowed for years at a time, by tightly sealing a consolidated object in polyethylene and preventing airflow from reaching it. This is particularly useful in the case of problematic finds for which there is neither enough time nor an appropriate method or material for a full treatment.

Cyclododecane is a temporary consolidant with many of the properties which made wax an attractive conservation material, such as its ease of application and immediate strengthening characteristics, without any of the drawbacks. Unlike traditional waxes which cannot be fully removed from an object by either chemical or mechanical means, cyclododecane sublimes from an object’s surface, i.e., goes from the solid state to the gaseous state, leaving no residue. This material is known from commercial applications in ceramics and metal powder manufacturing, as well as use as a sealing wax (Stein et al. 2000), and as an additive in fragrances and synthetic waxes (Brückle et al. 1999). First introduced into conservation in 1995 by Hans Michael Hangleiter, Elisabeth Jägers, and Erhard Jägers, cyclododecane is a cyclic alkane with the chemical formula C12H24. At room temperature, pure cyclododecane is a solid, translucent, crystalline material with a strong odor similar to camphor. It can be dissolved in non-polar solvents for use in solution, or heated to its melting point of 58–61°C and used directly as a melt. The solution or melt can be applied to an object’s surface with a variety of tools, including brushes, glass pipettes, heated spatulas, and wax-melting pens. Cyclododecane is also available as an aerosol.4

Within the conservation community, cyclododecane has been viewed warily because of two specific concerns. The first of these is the fear of residues remaining on and within objects which have been consolidated with cyclododecane. Caspi and Kaplan (2001) reported that any residue present was likely associated with compounds that are byproducts of the synthesis of cyclododecane, and that they are found in such small amounts as to pose no danger to artifacts. The second concern is the possible health hazards of the material. Most versions of the Material Safety Data Sheet (MSDS) in recent years note that the toxicity of cyclododecane is minimal, and that there are no known carcinogens present in the product.6 Nichols and Mustalish (2002) recommend taking measures against direct skin and eye contact, as well as inhalation, and protecting against hazards associated with solvents used to dissolve cyclododecane. In a museum context, these hazards can be easily avoided by using the material in a fume hood. On site, however, care must be taken to ensure that

The material characteristics of a cyclododecane film are greatly determined by the method of application; this topic has been studied extensively in several recent publications (Jägers and Jägers 1999; Brückle et al. 1999; Hangleiter 2000; Stein et al. 2000; Muros and Hirx 2004). In general, the literature concurs that films formed by the cooling of molten cyclododecane on a surface are dense, compact layers of small, needle-like crystals. By contrast, films formed by the comparatively slower evaporation of a solvent show a more open network of crystals than that seen in the melt. Finally, Muros and Hirx reported that the barriers formed from the aerosol are ‘made up of very small, slightly rounded crystals with spaces in between’ (Muros and Hirx 2004: 77). Of 4

5 Hangleiter mentions that the relationship between the sublimation rate of cyclododecane and the increase in temperature is not linear, i.e., that temperatures must be raised beyond a certain threshold for a significant change in the sublimation rate to occur. He refers to this as ‘an increasing of the temperature...in the decisive temperature range’ and notes that this is currently under study (Hangleiter 2000). 6 See www.msdsonline.com, under the entry for ‘cyclododecane’.

The aerosol is now available from Kremer Pigments.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS cyclododecane is used with adequate ventilation during both the application and sublimation processes.

conjunction with consolidation with cyclododecane because of the flexible working properties such a combination offered.

Concerns aside, cyclododecane has become of tremendous interest to the conservation community, with recent publications involving the use of this consolidant on a variety of materials, mainly in museum contexts. These include studies on cyclododecane’s applications for stone (Stein et al. 2000), ceramics (Caspi and Kaplan 2001; Muros and Hirx 2004), metals (Uhlig 2002), paper (Brückle et al. 1999; Keynan and Eyb-Green 2000; Nichols and Mustalish 2002), textiles (Larochette 2004), and in moldmaking (Maish and Risser 2002; Brückle et al. 1999). Most of the research conducted on the use of cyclododecane in the field or on site is found in the German literature; for example, Hangleiter (1998a, 1998b) writes on the transport and stabilization of wall paintings, and Jeberein (2002) examines its use in the lifting of unstable ceramic fragments. Recent work by Bucher and Snethlage (2004) describes the retrieval of sets of limestone body armor from the Burial Complex of Qin Shihuang in Lintong, China.7

On site, cyclododecane was applied exclusively as a melt. The aerosol was not considered for use at Abydos because the extreme force with which the cyclododecane is propelled out of the container would dislodge all but the most stable materials; furthermore, the resulting film is too thin to provide structural support to an object. The use of solutions of cyclododecane in non-polar solvents was also avoided both because of the difficulty of obtaining high quality solvents in Egypt, and the physical hazards associated with their use.8 In addition, many of the fragile materials that required lifting would not have tolerated wetting up with even highly volatile solvents such as acetone; in such cases, slow evaporating solvents such as xylene or mineral spirits were entirely inappropriate. Therefore, given the extreme time pressure to stabilize and lift materials, using cyclododecane as a melt was the quickest way to create a hard, strong coating which would allow an object to be fully excavated and lifted out of the ground, often in a matter of minutes.

Cyclododecane use at Abydos The 2002-2003 and 2004-2005 seasons of the Pennsylvania-Yale-Institute of Fine Arts NYU Expedition to Abydos involved a number of excavation units open at the same time. As previously mentioned, the site produced numerous finds daily, many of which were first stabilized and lifted by conservators in the field. With only two conservators on site at any one time, this volume of finds required a selective approach to indepth conservation treatments. The conservation strategy, therefore, was one of stabilizing objects in the field and in the conservation laboratory as quickly as possible, cleaning and reconstructing artifacts of substantial intrinsic importance, and packing vulnerable finds to ensure their survival in storage.

As there is no electricity available at the excavation, a small gas burner (similar to a camping stove) was taken out to the appropriate trench, and the required amount of cyclododecane was poured into an aluminum can.9 The can was heated until the wax became a clear, colorless liquid which was then dripped or brushed onto the surface of an object with a wide, flat bristle brush.10 The dripping method was particularly useful when consolidating fragile objects with friable or easily dislodged surfaces. The first layer of wax generally saturates and considerably darkens the surface, thus making still unstable and unconsolidated areas easy to recognize. After an initial consolidation layer, additional layers can be applied by brush until the appropriate thickness (and therefore strength) of the film is reached.11 Cheesecloth is often used between layers of cyclododecane to give additional structural support and

The main use of cyclododecane at Abydos was as a temporary consolidant for newly excavated finds which were too fragile to lift and/or transport to the conservation laboratory. Materials which appeared robust on excavation often deteriorated even in the relatively short time required for their documentation; this was most obvious with organic objects such as painted wood, leather, and textiles. Particularly in these latter cases, traditional consolidation treatments with acrylic resins and emulsions were impractical, as even slight wetting of the material would cause it to disintegrate. Facings of Japanese paper or synthetic tissue were also inappropriate because they required the objects to be quite clean of debris, took time to set up and dry, and often obscured the surface of interest. The two main concerns, however, were the amount of time required for the temporary consolidation, and the amount of effort required to reverse this consolidation and retreat the object at a later time. In general at Abydos, traditional conservation methods were used in

8 In order to make a saturated cyclododecane solution, the non-polar solvent sometimes requires slight heating. We were not comfortable attempting this on the temperamental gas camping stove available on site. 9 Cyclododecane is packed and shipped in aluminum cans with tight fitting lids. Not only could the material be heated directly in the cans, but it could also be stored in them with the lid firmly attached to prevent any sublimation between uses. However, the aluminum fatigued after several heatings, and tended to deform, char, or burn. To avoid this problem, cans were not reused after approximately six or eight reheatings. Petrie seems to have had similar problems finding a suitable wax receptacle. He recommended the use of a ‘cast-iron saucepan, as soldered tins may give way before the wax boils’ (Petrie 1904: 90). 10 [10] Hangleiter warns against using a brush because it ‘very often leads to unsatisfying results’ (Hangleiter, n.d.). At Abydos, however, this method worked efficiently. Round or bright tipped brushes are not recommended as they tend to hold in the cyclododecane (usually for so long as to let it solidify on the brush) and do not have the sharp edges that make dripping the material easier. 11 It must be noted that the final appearance of a cyclododecaneconsolidated surface is not an attractive one, and may alarm people who are seeing it for the first time.

7

I am thankful to Sandra Bucher for providing me with an advance copy of her paper.

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SANCHITA BALACHANDRAN: THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE tensile strength to the film. Once the object is suitably stabilized, it can literally be picked up, placed consolidated-side-down in a properly padded tray, and carried back to the dig house.

conservators and archaeologists time to consider the preservation and research goals for complicated artifacts, thus ensuring that any treatments undertaken in the future are carefully planned, well prepared, and executed within the available time frame.

One of the most important advantages of cyclododecane use at Abydos was the fact that it does not need to be actively reversed, thus saving the conservators considerable time and effort. As previously described, cyclododecane sublimes with exposure to airflow and with some elevation of temperature. On site, this meant that objects requiring treatment soon after retrieval from the field were placed under fans indoors, or outdoors in shaded areas to speed the sublimation. The sublimation of the cyclododecane is a relatively slow process that can easily be monitored with the naked eye; layers thin gradually until small ‘clean’ areas, i.e., those that are no longer saturated or wax covered, begin to develop.12 While the cyclododecane sublimed, objects were treated on the reverse side with more traditional methods such as backings of Acryloid B72 and Japanese tissue, or fills of plaster, or cellulose powder mixed with acrylic resin. By the time that the film had completely sublimed, the artifact was structurally stable and could be cleaned and consolidated as needed.13

Cyclododecane applications at Abydos: three case studies The following section discusses the application of cyclododecane in three different instances; though these case studies relate to specific artifacts at Abydos, the situations described are commonly faced by conservators and archaeologists on any excavation. Case study 1: a Middle Kingdom limestone stela A Middle Kingdom limestone stela was found in a mud brick chapel early in the 2002 season (Fig. 1). According to the field director, Matthew Adams, the discovery of a stela still within its original chapel context was an extremely rare occurrence. The excavators were interested in excavating this object whole, and reading its inscription. When first exposed, the stela was extremely unstable—the inscription was in poor condition and sections of the surface were delaminating and flaking. Cracks ran through its entire length and thickness, suggesting that there was little structural integrity to the object. As the inscription was the information which made this object of greatest interest to the archaeologists, it was carefully consolidated with Acryloid B-72 in acetone and reinforced with synthetic tissue. For overall temporary consolidation of the many cracks, molten cyclododecane was applied over cheesecloth, ensuring minimal movement in the inscription as the object was further excavated (Fig. 2). As archaeologists uncovered more of the stela, these exposed areas were also coated with cyclododecane. Before the object was detached from its mud brick chapel, a padded wooden board was secured to the front with ratchet straps and the object slowly laid down. More cyclododecane was applied to the back of the object while it was in this position, and finally another padded board was strapped into place to create a well-cushioned ‘sandwich’. The stela was then carried to the dig house where it was placed under fans to drive the sublimation of the cyclododecane. Given the thickness of the consolidant film, the sublimation of the wax took several weeks. Next, the synthetic tissue coatings applied with Acryloid B-72 were removed using acetone. A final cleaning of the stone surface with acetone and stabilization of loose chips with B-72 revealed a finely finished stone surface and a completely legible inscription (Fig. 3).

Another distinct advantage of cyclododecane is its use in the long-term stabilization of materials that cannot be treated during the season, or for which there is no immediate or appropriate solution. As long as a consolidated object is not exposed to airflow, the cyclododecane film will remain intact and stable for years at a time.14 Wooden boat planks consolidated with cyclododecane and excavated by Becker and Schorsch in 2000 were packed in airtight Marvelseal bags within wood boxes with tight fitting lids; observations of the planks over the past five years show that they are in stable condition, and that there has been minimal sublimation of the cyclododecane within the packing materials.15 In recent seasons, other materials such as wooden coffin planks and painted coffin fragments have been consolidated with cyclododecane, wrapped in polyethylene, and placed in well-sealed boxes for longterm storage. This method of stabilization gives both 12 Hangleiter discourages both the chemical and mechanical reduction of cyclododecane films. From experience at Abydos, attempts at mechanically removing the film with sharpened wooden tools or scalpel blades tended to pull away flakes of the consolidant with fragments of the object’s surface still attached. 13 Riedl and Hilbert (1998) found that cyclododecane can remain within the pores of an object several months after the surface film has sublimed. This fact raises questions about potential interactions between the cyclododecane and any additional conservation materials (cleaning agents, fills, or consolidants) which may be applied to the surface of an object that has been pre-consolidated with cyclododecane. No studies have as yet addressed this issue. 14 Neuner and Hubert (2001) note that objects with mildew and mold problems can be consolidated using cyclododecane without fear of these biological problems worsening during the transport of the objects. So far, there is no published research on how long biological growth would remain contained in a cyclododecane film. 15 Some sublimation does occur within storage as small clumps of crystals can be found on the inner surfaces of the packing. However, this appears to be minimal.

Initially in an extremely unstable condition, the object was transformed into a stela with a clear and crisply tooled inscription. This work changed expectations regarding the kinds of finds that could be excavated without loss, and the ability to conserve them and provide details that would otherwise remain obscured.

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Figure 1: The stela as found, before treatment. Figure 3: The stela after treatment.

Case study 2: a Post–New Kingdom coffin burial Archaeologists uncovered a post–New Kingdom coffin burial in an extremely fragmentary state. Excavation revealed an exquisitely painted inner coffin and cartonnage, as well as two delicate face masks, perhaps associated with the inner and outer coffins (Fig. 4). Documentation in situ of the coffins with their elaborate decoration necessarily took an extended period, during which they deteriorated significantly, leaving some painted areas as little more than pigment particles on thin plaster or wood wafers. Given their beauty and general visual integrity, it was agreed that the faces, or masks, should be retrieved. This was carried out by first consolidating the wood surfaces with dilute solutions of Acryloid B-48N in acetone where possible. Then the unstable plaster and wood were coated with cyclododecane and reinforced with cheesecloth for structural strength. Once stabilized, the surrounding sand was removed and the objects gently lifted out (Fig. 5). In the conservation lab, the masks were backed using Japanese tissue and methyl cellulose, and losses were filled with cellulose powder and methyl cellulose. While the masks had been relatively simple objects to remove, and were inherently recognizable as ‘objects’, the fragmentary coffins were another issue; even if one could be lifted (something which seemed quite unlikely given its fragile condition), it would survive only as a jigsaw puzzle (Fig. 6). Furthermore, as the main interest of the expedition is in Early Dynastic material, it was a dilemma as to whether this Middle Kingdom object, given its problematic condition and the fact that it had

Figure 2: After consolidating the stela with cyclododecane and cheesecloth.

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SANCHITA BALACHANDRAN: THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE Initial efforts to consolidate the painted decorations with an acrylic resin were abandoned as the added weight and wetness of the solvent collapsed these delicate areas. The sarcophagus could not be cleaned or brushed free of sand in large sections because this disturbed friable pigment particles and dislodged plaster and wood fragments. Molten cyclododecane was first applied as a drip directly on painted plaster, and this was followed by brushing on thicker layers of cyclododecane that possible, the backs and/or interior sections of the sarcophagus were consolidated with cyclododecane rather than the decorated surfaces, thus making identification of the individual sections of the object possible. As parts of the sarcophagus were retrieved, their locations were marked on a drawing prepared by Sandra Wheeler, one of the Expedition’s artists. By the end of the day, nearly two-thirds of this fragile artifact had been retrieved. It was moved to the dig house where it was packed in an airtight bag within a padded box to prevent any sublimation of the cyclododecane. An examination of the object two years after excavation showed that it was in remarkably stable condition.

been well documented, should be lifted at all. It was clear, however, that such an object would never survive reburial and re-excavation; it was equally clear that even if lifting it were successful, considerable conservation time and effort would have to be dedicated to making the sarcophagus ‘whole’ or even legible again. Ultimately, there was a general consensus that since they would not survive reburial and future re-excavation, this was the only opportunity to retrieve as much of the coffins as possible.

Though the sarcophagus will require significant conservation to be a complete object again, it exists as physical evidence that may be of value to scholars in the future. The success of lifting this artifact surprised the conservators and archaeologists alike. Most important, this experience showed that less robust materials could be successfully stabilized and removed.

Figure 4: Detail of the face masks as found, before treatment.

Figure 5: Lifting a mask after consolidation with cyclododecane and cheesecloth.

Figure 6: Detail of the painted inner coffin, before treatment.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS

Figure 9: After consolidating the basin edges with molten cyclododecane.

First, the intact parts of the basin were reburied in sand for protection. Before applying any conservation materials on the object, the dark gray residue in the bowl was sampled for future chemical analysis.16 The exposed limestone was then stabilized with molten cyclododecane (Fig. 9). The basin was slowly excavated and stabilized in turn until it was completely visible. Due to its new smooth, hard wax coating, the basin could be reburied at the end of a workday and quickly re-excavated the next day. During the several days required to fully excavate and document the area, the cyclododecane barrier and the basin remained intact (Fig. 10). The trench was reburied at the end of spring 2003 with the basin still consolidated. The use of cyclododecane in this area is clearly noted in both the archaeological and conservation documentation of the work from the season; this information will serve as a guide to future scholars and excavators.

Figure 7: Consolidating areas of the painted coffin with cyclododecane and cheesecloth.

Case study 3: an Early Dynastic limestone basin A large limestone basin found at the entrance of the First Dynasty royal funerary enclosure was thought to play an important ritual function. Immediately after the object was excavated, the once smoothly carved and finished limestone began fracturing into hundreds of sizeable fragments (Fig. 8). A dark gray residue inside the bowl, possibly related to the object’s original use, was in danger of being lost. Though the large size and weight of the basin necessitated leaving it in the field, archaeologists planned to fully excavate the object in order to understand how it fit into the surrounding context. It was clear that the basin would collapse if not stabilized prior to further excavation; it was also evident that the basin would not survive reburial and future excavation if buried in its fragmentary and structurally unstable state.

Figure 10: The consolidated basin in situ in its fully excavated context.

The stabilization of the basin raised questions about the responsibility of the archaeologist and conservator to objects that will remain in the field, and how the archaeological record can be protected for the next generations of investigators. Historical precedent shows 16 As is protocol in most museums and on archaeological sites, materials which may require analysis in the future are always sampled before the application of any conservation materials.

Figure 8: The basin as found, before treatment.

84

SANCHITA BALACHANDRAN: THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE that sites are constantly re-excavated; keeping this in mind, the treatment of the basin suggests perhaps one approach by which artifacts may be kept somewhat intact in their original context for future excavators.

long-standing dilemmas faced by conservators and archaeologists, enabling the retrieval of fragile artifacts which would otherwise be lost. The use of cyclododecane also has the potential to fulfill the professional goals of both conservators and archaeologists: it allows for the maximum preservation of the archaeological record and thereby provides for scholarship and for posterity the information that only excavated materials can disclose.

Future research The history of the field of conservation is replete with any number of miracle materials which were meant to be completely reversible, inert, and non-toxic. Conservators spend much of their time undoing the work of previous generations of colleagues, or bemoaning their indiscriminate use of materials which failed in both the short and long term. In this context, is important to consider cyclododecane as yet another tool among the conservator’s resources, but one that should be used appropriately and judiciously for particular tasks. While most recent studies have concentrated on cyclododecane’s material characteristics, significant work remains to be done on the way it affects the materials on which it is applied, and whether the application method itself affects an object’s long-term stability. For example, does the use of molten cyclododecane result in thermal shock to an object’s surface, and does this temporary heating have the potential to cause accelerated aging?17 Can the heat of the molten consolidant affect pigments or coatings? Can traditional consolidants, cleaning products, and cyclododecane be used on the same object without fears of problematic interactions between the materials? Are there concerns with the long-term stabilization of objects (either in storage or in the ground)? Are there environmental concerns with burying cyclododecane? How effective is the hydrophobic character of the cyclododecane film on objects reburied in wet or saltladen environments? Though the focus of this paper has been on the stabilization of artifacts, how might cyclododecane be used for the preservation of architectural remains on site during both excavation and reburial?

Acknowledgements I would like to thank Dr. David O’Connor, Dr. Matthew Adams, and Laurel Bestock for the opportunity to work at the Abydos North Cemetery. I am grateful to conservators Mark Benford Abbe and Deborah Schorsch, whose hard work and collegiality made conservation work at Abydos so gratifying. The Expedition teams for the Fall 2002 and Fall 2004 seasons were exceptional—I owe special thanks to Holly Anderson, Jerrie Clarke, Bob Fletcher, Diane Kagoyire, Stine Rossel, Jody Waldron, and Sandra Wheeler. I am grateful to Cameron Trowbridge and Valerie Greathouse at the Getty Conservation Institute who helped me gain access to many of the conservation publications cited in this paper. Sandra Bucher and Yadin Larochette kindly shared copies of their papers. Many thanks to Gary McGowan who introduced me to cyclododecane and its remarkable applications. I would also like to thank Amy Jones Abbe, Lawrence Becker, Tania Collas, Molly Lambert, Kent Severson, and Glenn Wharton for their advice on various aspects of archaeological conservation. Bibliography American Institute for Conservation of Historic and Artistic Works. 1994. Code of Ethics. http://aic .stanford.edu/about/coredocs/coe/index.html (redirects to http://www.conservation-us.org/, accessed June 2009). Brückle, I., T. Thornton, K. Nichols, and G. Strickler. 1999. Cyclododecane: technical note on some uses in paper and objects conservation. Journal of the American Institute for Conservation 38: 162-175.

An important new issue raised by the ease of application and complete reversibility of cyclododecane is whether it should be part of every archaeologist’s tool kit, particularly when a conservator is not present on site. How might this tool encourage excavators to preserve more of the archaeological record? How would this affect the way conservators and their skills are viewed and valued by archaeologists?

Bucher, S., and R. Snethlage. 2004. The stone armor from the burial complex of Qin Shihuang in Lintong, China: methodology for excavation, restoration and conservation, including the use of cyclododecane, a volatile temporary consolidant. Paper presented at the Second International Conference on the Conservation of Grotto Sites, Dunhuang, China, June 28–July 3, 2004.

While many questions remain to be answered about cyclododecane and its applications, it is a remarkable material with many promising applications in the field. This temporary consolidant offers new approaches to

Caspi, S., and E. Kaplan. 2001. Dilemmas in transporting unstable ceramics: a look at cyclododecane. American Institute for Conservation Objects Specialty Group Postprints 8: 116-135.

17

Recent articles have commented on potential problems with the use of molten cyclododecane on paper and textiles. Keynan and Eyb-Green (2000) suggest further research be conducted into whether the application of cyclododecane changes the fiber structure of paper. Larochette (2004) notes that while significant heating of organic surfaces such as textiles can hasten deterioration mechanisms, the amount of heat generated while applying molten cyclododecane most likely does not affect those mechanisms.

Chevalier, S. 2001. Le Cyclododécane: un agent de protection temporaire? Les effets de son application sur différents traces et papiers. Conservation Restauration des Biens Culturels 17/18: 69-73.

85

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Keynan, D., and S. Eyb-Green. 2000. Cyclododecane and modern paper: a note on ongoing research. Western Area Art Conservators Newsletter 22: 18-21.

Gänsicke, S., P. Hatchfield, A. Hykin, M. Svoboda, and M. Tsu. 2003a. The Ancient Egyptian Collection at the Museum of Fine Arts, Boston. Part 1, a review of treatments in the field and their consequences. Journal of the American Institute for Conservation 42: 167-192.

Larochette, Y. 2004. Determining the efficacy of cyclododecane as a barrier for a reduction bleaching treatment of a silk embroidered linen napkin. The Textiles Specialty Group Postprints 14: 1-10.

Gänsicke, S., P. Hatchfield, A. Hykin, M. Svoboda, and M. Tsu. 2003b. The Ancient Egyptian Collection at the Museum of Fine Arts, Boston. Part 2, a review of former treatments at the MFA and their consequences. Journal of the American Institute for Conservation 42: 193-236.

Lucas, A. 1932. Antiques. Their Restoration and Preservation, 2d. ed. London: Edward Arnold and Co. Maish, J., and E. Risser. 2002. A case study in the use of cyclododecane and latex rubber in the molding of marble. Journal of the American Institute for Conservation 41: 127-137.

Gilberg, M. 1987. Friedrich Rathgen: The father of modern archaeological conservation. Journal of the American Institute for Conservation 26: 105-120. Gilberg, M. 1997. Alfred Lucas: Egypt’s Sherlock Holmes. Journal of the American Institute for Conservation 36: 31-48.

MSDSonline. n.d. Cyclododecane. http://msdsonline .com (accessed June 2009).

Hangleiter, H. n.d. Cyclododecane. http://www .hangleiter.com/html_e/index_.htm (accessed June 2009).

Muros, V., and J. Hirx. 2004. The use of cyclododecane as a temporary barrier for water-sensitive ink on archaeological ceramics during desalination. Journal of the American Institute for Conservation 43: 75-89.

Hangleiter, H. 1998a. Erfahrungen mit flüchtigen bindemittel. Restauro 104: 314-319.

Neuner, M., and M. Hubert. 2001. Le cyclododécane: nouvelles perspectives. Conservation Restauration des Biens Culturels 17/18: 61-68.

Hangleiter, H. 1998b. Erfahrungen mit flüchtigen bindemittel teil 2, Restauro 104: 468-473.

Nichols, K., and R. Mustalish. 2002. Cyclododecane in paper conservation discussion. The Book and Paper Group Annual 21: 81-84.

Hangleiter, H. 2000. Temporary protection of sensitive surfaces about the usage of volatile binding agents. http://www.hangleiter.com/html_e/index_ .htm (accessed June 2009).

Petrie, W. 1904. Methods and Aims in Archaeology. London: Macmillan and Co.

Hangleiter, H., and L. Saltzmann. 2005. Cyclododecane—new ideas for application. http://www.hangleiter.com/html_e/index_.htm (accessed June 2009).

Riedl, N., and G. Hilbert. 1998. Cyclododecan im putzgefüge. Restauro 104: 494-499. Stein, R., J. Kimmel, M. Marincola, and F. Klemm. 2000. Observations on cyclododecane as a temporary consolidant for stone. Journal of the American Institute for Conservation 39: 355-369.

Hangleiter, H., E. Jägers, and E. Jägers. 1995. Flüchtige bindemittel. Zeitschrift für Kunsttechnologie und Konservierung 9: 385-392. Hiby, G. 1997. Das flüchtige bindemittel cyclododecan. Restauro 103: 96-103.

Uhlig, U. 2002. Cyclododecan für archaeologische funde? Konservierung von archaeologischem eisen. Restauro 108: 580-583.

Jägers, E., and E. Jägers. 1999. Volatile binding media— useful tools for conservation. In Reversibility—Does it Exist? British Museum Occasional Papers 135, ed. A. Oddy. London: British Museum.

Sources of Materials Acryloid B-48N Conservation Resources International, LLC 5532 Port Royal Road Springfield, Virginia 22151

Jeberien, A. 2002. Cyclododecan für archaeologische funde? Bergung stark fragmentierter keramik der Hallstattzeit. Restauro 108: 509-511.

Acryloid B-72 Talas 20 West 20th Street, 5th Floor New York, NY 10011

Johnson, J., 1994. Consolidation of archaeological bone: a conservation perspective. Journal of Field Archaeology 21: 221-233.

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SANCHITA BALACHANDRAN: THE USE OF CYCLODODECANE IN FIELD STABILIZATION AND STORAGE Cyclododecane Kremer Pigments Inc. 247 West 29th Street New York, NY 10001 Biography Sanchita Balachandran holds graduate degrees in conservation and art history from the Institute of Fine Arts, New York University. She completed post-graduate internships at the J. Paul Getty Museum and the Straus Center for Conservation, Harvard University Art Museums. Balachandran is a conservator in private practice in Baltimore, Maryland. She currently teaches courses in conservation history and ethics as well as collection management at the Johns Hopkins University and Morgan State University. Address 3714 Beech Avenue Baltimore, MD 21211 USA

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NEW PERSPECTIVES REGARDING THE STABILIZATION OF TERRESTRIAL AND MARINE ARCHAEOLOGICAL IRON Paul Mardikian, Néstor G. González, Michael J.Drews, and Philippe de Viviés Abstract For decades, the conservation of archaeological iron has challenged conservators. A variety of techniques has been used in an attempt to mitigate the negative effects of chloride ions on iron artifacts and prevent these items from disintegrating. This article briefly reviews milestones in the history of iron conservation, major issues regarding iron stabilization, and the current iron conservation research being conducted at the newly formed Clemson Conservation Center, home of the H.L Hunley submarine (1864) in Charleston, South Carolina.

to determine the most suitable method for ensuring the long-term preservation of this complex composite vessel, a collaborative research effort was initiated between Friends of the Hunley, Inc., and Clemson University. Since early 2003, the Warren Lasch Conservation Laboratory in North Charleston, South Carolina, has been evaluating traditional stabilization techniques and testing an experimental treatment for the removal of chloride from archaeological cast and wrought iron artifacts. The use of alkaline solutions under subcritical conditions has been tested as a new treatment option, and the results obtained compared with those from experiments using more traditional approaches such as alkaline soaking with and without electrolysis.

Introduction It is hard to refrain from quoting Neil North, a pioneer of conservation sciences, when beginning this article: A definition of a successful conservation treatment for archaeological iron is that the stability of the artifact outlasts the conservator’s employment with the organization. (North 1975)1

Iron conservation—historical approaches In the early years, physical protection was used on ancient iron with the intent of creating an impermeable barrier to air. Iron corrodes when exposed to the air and therefore many people assumed that protecting recently excavated artifacts would be just like protecting modern iron. Various substances were utilized, such as paint, oil, wax, lacquers, gelatin, Vaseline, rubber, or resins (Jakobsen 1988; Häyhä 1999). Some practitioners suggested boiling the artifacts in a mixture of wax and linseed oil while others recommended the use hydrochloric acid and glycerin (Häyhä 1999: 4).

Although this quote was made more than 30 years ago, one of the objectives of the present article is to determine if this statement still applies today. For more than a century, archaeological iron has been treated with almost everything imaginable to prevent it from deteriorating. Iron artifacts have been subjected to a variety of treatments: coatings, impregnations, soaking in various chemicals, electrolysis, steaming, annealing, gaseous reduction (such as hydrogen reduction or cold plasma), to name just a few approaches. The number of damaged or lost artifacts over the years is impossible to assess but is presumably large. One of the biggest challenges in evaluating the merit of any conservation technique is how to assess the condition of the material before and after treatment. Characterizing the nature of the corrosion products, their appearance and mechanical strength, and the chloride levels are key criteria in assessing whether a treatment was successful or not. When the Civil War submarine H.L Hunley (1864) was raised from the Atlantic Ocean on August 8, 2000, after 136 years of marine corrosion, it was known that a major conservation challenge would have to be faced. In order

In 1882, a step forward was made when German scientist Edward Krause published an article about the importance of eliminating soluble salts from iron in order to stabilize it (Jakobsen 1988: 51–52). He recommended using hot and cold distilled water until no chloride could be detected in the solution. Krause also mentioned that insoluble salts were harmless to the metal. Later references indicate that many of the artifacts conserved by Krause had to be retreated by the turn of the century and very few, if any, survive to the present day (Jakobsen 1988). Another turning point occurred in 1892 when Axel Krefting, a Norwegian, published an article on the influence of soluble salts on archaeological iron, and the way to conserve ancient metal artifacts (Jakobsen 1988: 54). Krefting, an engineer and amateur archaeologist, claimed that the only way to get rid of the salts was to strip the corrosion products to the bare metal using a method called ‘electrolytic de-rusting’. He noted that the best way to achieve this goal was to use a 5% solution of sodium hydroxide.

1 This quote from Neil North was never published. It was related to us by Ian MacLeod as part of the oral tradition of the Western Australian Maritime Museum. It was recently sent to Neil North to review for this publication. Neil wrote, in an email to Paul Mardikian, dated January 23, 2006: ‘I can’t remember the exact quote in question but it certainly sounds like me. This quote was probably made in reference to conservation about 30 years ago, that is mid 1970’s when I first started. There was almost nothing known about marine iron conservation in those days and recovered marine iron artifacts, particularly cast iron, often did not last long after “treatment”. When I left the field in the mid 1980’s the situation was still not perfect but it was a darned site better than it had been 10 years earlier. Do remember though that the quote was made sarcastically’.

William Nicholson had discovered the decomposition of water using electrolysis in 1800. Friedrich Rathgen, a scientist hired by the Royal Museums of Berlin in 1888, used this technique on ancient bronze artifacts to stop their alarming corrosion believed to be due to a fungus. Rathgen had heard about this technique from Adolph 89

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Boissonnas 2002). It was hoped that pretreating metal samples from the Hunley with cold plasma would have a marked effect on the ability of Cl-1 ions to diffuse out into sodium hydroxide solutions. Unfortunately, no evidence to support this theory was found in the case of wrought iron samples pretreated in France by Materia Systems. Even if these experiments had been successful, an important technological barrier would be to scale up the small plasma chamber currently used in France to a size appropriate for the Hunley materials. Additionally, the testing of a new type of microwave plasma applicator that could be used on the interior and exterior surfaces of the submarine would have been required. It was concluded that there was presently no way to justify using cold plasma on the Hunley (Drews et al. 2004; Mardikian 2004).

Finkener, a chemist at the Bergakademie in Berlin (Gilberg 1987). Rathgen’s technique utilized potassium cyanide as an electrolyte: a rather dangerous chemical compared to sodium hydroxide. Later, Rathgen modified his protocol in order to conserve small artifacts such as bronze coins. The coins were sandwiched between zinc plates in a bath of dilute sodium hydroxide. It is hard to tell for sure who the first ‘conservator’ was to apply electrolysis to the stabilization of archaeological iron, but one can reasonably assume that it was Krefting. Krefting’s technique drew a lot of interest due to the relative efficacy of the treatment but was also criticized for the ‘stripped’ appearance of many artifacts after treatment. With time, however, it became apparent that electrolysis was not suitable for all types of iron artifacts. One of the major problems encountered at that time was that many of the corroded iron artifacts retrieved from a terrestrial site did not have enough metal left to establish an electrochemical cell. In addition to his work with electrolysis, Krefting also recommended using paraffin wax to protect the artifacts after treatment.

The Australian contributions to the field Electrolytic treatments remain a subject of discussion and controversy. Notable is the lack of consensus regarding how to use the technique reliably and effectively on cast iron objects recovered from a marine environment (North and Pearson 1978; McCarthy 2000; Dalard et al. 2002; O’Guinness Carlson et al. 2003; Mardikian et al. 2004). Other areas of contention include the choice of the electrolyte, the choice between constant current or potential, the size, nature, and placement of the anodes, and even the role of the electric field in the Cl-1 removal process. North and Pearson (1978) wrote:

Thermal and gaseous reduction treatments The thermal treatment (annealing) of iron artifacts retrieved from a marine environment in order to volatilize the chloride ions has been around for almost 150 years. Aagaard (2003) cites the work initiated by Mauritz Rasmussen Schmidt at the Danish Defense Museum in 1858. This technique, along with the more elaborate and preferred ‘hydrogen furnace’ technique, has been extensively criticized in the conservation literature because of the variability in the results and the changes that occur in the iron at such high temperatures (up to 1060°C). However, thermal treatments have been regularly suggested and tested to stabilize marine artifacts in an attempt to find more reliable and faster conservation techniques.

The presence of the electric field has an insignificant effect on the rate of chloride ion extraction. In brief, electrolysis is a pretreatment of the artifacts so that the simple washing can proceed more rapidly. Once the reduction in the corrosion products has occurred, the role of electrolysis should be minimal and the chloride diffusion in a 2% NaOH solution should constitute the main driving force. The principal effect of electrolysis is the reduction of the corrosion products leading to a faster Cl-1 diffusion, due to the increased porosity of the graphite matrix as a result of electrolytic treatment (North and Pearson 1978). Others have shown that if the gas evolution at the surface of the artifact is too vigorous, the rate of Cl-1 released into the solution can be reduced (Carlin et al. 2002). The success of ‘electrolytic reduction’ can be explained by the apparent simplicity of the process and the formidable potential it has for cleaning metal surfaces. However, along with the extremely long treatment times (Logan 1989), there is a significant risk that the original surface may be lost (particularly on cast iron artifacts):

A modified version of the hydrogen furnace treatment was studied at the Western Australian Maritime Museum in Fremantle, Western Australia. Neil North found that at a temperature of 400°C, good reduction could be achieved and the metallurgical history of the object could be retained. At this temperature, a subsequent washing in dilute caustic was necessary to diffuse the chloride ions out of the corrosion products. Excellent results were reported on deeply graphitized cast iron cannon balls (North et al. 1976; North and Pearson 1977). Treated samples from the Xantho (1871) were analyzed at the Warren Lasch Conservation Laboratory. Chloride ion concentrations ranging from 250 ppm to 1100 ppm were measured. Recently, the modified hydrogen furnace from the Western Australian Maritime Museum was decommissioned due to health and safety regulations (Carpenter 2005).

Electrochemical stabilization in potentiostatic mode is still a fairly long procedure and weakens the objects due to the difficulty in preventing hydrogen evolution. No matter how many precautions are taken, the materials can end up fracturing during treatment. (Dalard et al. 2002)

Gas plasma treatments were introduced in conservation by Daniels et al. (1979) and have been further developed in Europe with mixed results. The desalination of terrestrial iron in alkaline sulfite after a ‘standard plasma treatment’ has been reported to be up to four times faster with this pretreatment than without (Schmidt-Ott and

This is particularly true for large marine artifacts due to 90

PAUL MARDIKIAN, NÉSTOR G. GONZÁLEZ, MICHAEL J.DREWS, AND PHILIPPE DE VIVIES: NEW PERSPECTIVES their lack of accessibility in the treatment tanks. Dalard et al. have suggested using pulsating current techniques to ameliorate the way electrolysis is conducted on marine cast iron. It is hoped that this technique will be tested on real artifacts as opposed to artificially corroded samples and the results compared to traditional treatments including soaking extractions in caustic. Additionally, perhaps the idea of simply pretreating the artifact with electrolysis should receive more attention from marine conservators (North and Pearson 1975).

practical standpoint, the presence of this corrosion product might significantly complicate stabilization treatments and explain why certain artifacts become almost impossible to stabilize after they have dried out to some extent. In addition, exposure to the atmosphere and drying can cause surface loss in graphitized cast iron when it is placed in sodium hydroxide solutions. It is important to note that this kind of adverse reaction is not known to occur on freshly deconcreted marine artifacts, but can occur on terrestrial artifacts placed in sodium hydroxide.

In 1975, North and Pearson introduced the alkaline sulfite technique as an alternative method for stabilizing marine archaeological cast iron. This technique became quite popular for the stabilization of small terrestrial artifacts; however, its application to large marine artifacts has been very limited. Reasons for that include the technical difficulties associated with heating the solution and the need for airtight containers to prevent oxygen from reacting with the chemicals. In France, the alkaline sulfite technique has been used for over 20 years with reasonable success for the mass treatment of terrestrial iron artifacts (Loeper-Attia and Weker 1995). Critical reviews designed to determine the merits of different conservation techniques and evaluate their impact on the survival rate of entire collections indicate that the alkaline sulfite technique remains the most successful stabilization treatment available to date for terrestrial iron (Keene 1994; Selwyn and Logan 1993; Watkinson 1996; Selwyn 2004). This being said, drawbacks to this technique include the potential for damaging the surface of certain artifacts, the long treatment times required, the residual sulfate ions left in the material, and the problems of measuring the chloride ions in the sulfite solutions. Additionally, not all terrestrial artifacts can be successfully stabilized with this technique (Beaudoin et al. 1995).

In several of the research studies conducted at the Warren Lasch Conservation Laboratory, the effectiveness of various modes of electrolysis was tested and compared to soaking in caustic solutions. Recent data seem to indicate that the two treatments (i.e., soaking and electrolysis) produce essentially the same results on wrought iron in terms of Cl-1 extraction rates and residual Cl-1 levels after treatment. A similar trend was found on marine cast iron, although the chloride release appears to be faster in the early stages of the electrolysis for this material. More work is under way to analyze the residual chloride content and characterize the corrosion products in these experimental samples before and after treatment (González et al. 2007). However, this finding appears to confirm North and Pearson’s observation that once the reduction in the corrosion products has occurred, the role of electrolysis is minimal and chloride diffusion in a 2% NaOH solution constitutes the main driving force (North and Pearson 1975). The role of NaOH as a chloride extraction medium is clearly more significant than originally thought. In order for the diffusion technique to work, the surface of the corroded metal must be as free of concretion as possible before the treatment starts. The chemical should preferably be circulated and the formation of carbonates prevented. In addition, the electrochemical potential of the artifact must be regularly monitored along with the pH of the solution. It is also critical to inspect the artifacts on a regular basis during the process. Current research at the Warren Lasch Conservation Laboratory confirms that sodium hydroxide solutions are much more efficient than sodium carbonate solutions for the stabilization of marine iron. However, sodium hydroxide solutions are less stable than sodium carbonate solutions, probably due to the depletion of OH- during the exchange with Cl-1 and the following reactions that decrease the pH of the solution through direct exposure to the air:

The power of strong alkalis A number of authors have shown that chloride ions can be extracted from archaeological iron by diffusion in caustics without electrolysis or the use of a reducing agent (Pearson 1987; Keene 1994; Turgoose et al. 1996; Al-Zahrani 1999; González et al. 2003; Drews et al. 2004; Degrigny and Spiteri 2004; Selwyn 2004). Although this technique has given inconsistent results in the past (Pearson 1987), there is more evidence now to support the idea that the Cl-1 level in deconcreted marine wrought or cast iron can be reduced to a very low limit just by simple diffusion in sodium hydroxide solutions. One notable exception to this observation is when βFeOOH (akaganeite) has formed in the presence of soluble Cl-1 ions (Drews et al. 2004). This chemical transformation seems to occur only when the metal is exposed to oxygen and to some degree of drying (Gilberg and Seeley 1982; Drews et al. 2004).2 From a

CO2 ( g ) + OH − ( aq ) ↔ HCO3 HCO3

−

( aq )

−

( aq )

+ OH − ( aq ) ↔ CO3−2 ( aq ) + H 2 O

In his experimental study, Al-Zahrani (1999) used sodium hydroxide solutions de-aerated with nitrogen. Although Al-Zahrani does not explain the technical reason for using an inert gas, we can assume that this precaution was undertaken to prevent carbonates from forming and to lower the pH of his solutions, which, in

2 ‘While akaganeite could play a similar role in iron objects excavated from marine sites, it has not been clearly demonstrated that this oxyhydroxide can form in-situ in the marine environment and may only form on marine artifacts after excavation and under the appropriate exposure conditions’ (Drews et al. 2004: 248).

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS turn, could play a role in reducing the efficiency of the Cl-1 removal process.

Conclusion So far, in spite of many early promises, no Cl-1 removal technique has been demonstrated to be effective on all types of archaeological iron (Knight 1997; Keene 1994; Selwyn 2004; Watkinson 2004; Drews et al. 2004). No conservator can predict with any degree of certainty if an artifact will remain stable after it is treated unless it is stored under very controlled conditions such as at a relative humidity of 12% or less (Watkinson 2004) or under an oxygen-free/low-RH system (Mathias et al. 2004; Mardikian 2004). More work is required to fill the gaps in our current knowledge (Selwyn 2004). It has not been clearly demonstrated that any of the traditional treatments can stabilize artifacts where β-FeOOH has formed. Only the future will tell whether or not subcritical fluids have the ability to meet this challenge. Much more work is needed to verify if this technique can be applied to larger and more complex artifacts such as riveted plates, engine parts, and cast and wrought iron structures. The preliminary goal here was to determine if this technique could be of any assistance to conservators working on iron artifacts recovered from both marine and terrestrial sites or on already treated but still unstable artifacts. So far, the data collected are sufficiently promising to merit further funding in order to carry this project forward and ‘scale up’ the system for larger pieces or mass treatment of archaeological iron. Funding and financial support are now necessary to go to the next stage of investigation. While it is true that the research and development of the subcritical water treatment could require considerable initial investment, the potential for reducing the long-term costs of lengthy conservation processes and expensive storage schemes is great. If this new approach if feasible, it might result in significant savings and will help the conservation community preserve one of the most endangered portions of our archaeological heritage.

Subcritical fluids This study originated from the work carried out at the School of Materials Science and Engineering at Clemson University (Drews et al. 2001). To date, over 100 experiments using subcritical fluids have been conducted at the Warren Lasch laboratory on wrought and cast iron samples. Subcritical water is water maintained at a pressure above atmospheric pressure and 100°C and below the critical temperature and pressure of water, Tc=374°C, Pc=220 bar. In the subcritical region, the transport properties of water as a solvent medium will be between those of liquid water and those of supercritical water. It was hypothesized that by using subcritical water solutions, the treatment time would be significantly reduced for the following reasons: • The increase in temperature of the treatment solution would result in a significant increase in the Cl-1 diffusion constants. • The decrease in the viscosity and density of the treatment solution would improve the diffusion of OH- into the corrosion layers and promote a more effective Cl-1 anion exchange. Samples from the Hunley, two samples from the Civil War ironclad USS Monitor (1862), and several cast iron samples from two Civil War era artillery shells with graphitized layers ~1 cm thick were tested. Experiments were conducted within a temperature range of 130 to 230°C. These temperatures were selected as representing the best compromise between practical considerations (primarily of size) and treatment effectiveness. In addition, the pH was varied from 11.6 to 13.1 and the reactor size increased from 40 to 600 ml. A 40-liter reactor has been designed for the next phase of the research. In these experiments, the subcritical water treatment effectively removed very high levels of Cl-1 from the samples in very short periods of time. None of the treatments exceeded 10 days, compared to more than 6 months of treatment using traditional techniques on some of the comparative cast iron specimens.

Acknowledgements The authors would like to thank the State of South Carolina (Hunley Commission), the Friends of the Hunley Inc., the Condensed Matter and Materials Physics Research Group at Old Dominion University, Clemson University’s School of Materials Science and Engineering and the College of Engineering and Science for supporting this research. We are also grateful to Emily Williams, Neil North, Ian McLeod, Jon Carpenter, Desmond Cook, Silvia Pain, Maria Jacobsen, Monique Drieux, Marie-Anne Loeper-Attia, and Shannon de Viviés for their assistance.

In a very limited set of experiments, simple soaking in NaOH alone was not effective at removing all of the Cl-1 from metal shavings resulting from the drilling of the rivets of the Hunley that had been allowed to completely dry out in air and form akaganeite (β-FeOOH). This analysis was performed by electron microprobe, microRaman analysis, and optical microscopy by Dr. Desmond Cook at Old Dominion University, Norfolk, Virginia. By contrast, subcritical treatment of comparative samples successfully removed all of the Cl-1. More importantly, it was shown that the subcritical treatment resulted in the apparent transformation of β-FeOOH into other iron oxides (de Viviés et al. 2007). The physical appearance of all the subcritical treated specimens, their mechanical properties, and their apparent corrosion resistance (even those stored in a high relative humidity for at least two years) appear to be very good, and the results from these experiments continue to be extremely encouraging.

References Aagaard, J.G. 2003. Thermal treatment of archaeological iron. BROMEC8: Bulletin of the Research on Metal Conservation 8: 19-20. Al-Zahrani, A. 1999. Chloride ion removal from archaeological iron and β-FeOOH. Ph.D. diss., University of Wales, UK. Beaudoin, A., M. Clerice, J. Francoise, J. Labbe, M. Loeper-Attia, and L. Robbiola. 1995. Corrosion d’objets 92

PAUL MARDIKIAN, NÉSTOR G. GONZÁLEZ, MICHAEL J.DREWS, AND PHILIPPE DE VIVIES: NEW PERSPECTIVES Gilberg, M., and N. Seeley. 1982. The alkaline sodium sulfite reduction process for archaeological iron: a closer look. Studies in Conservation 27: 180-184.

archeologiques en fer après dechloruration par la methode au sulfite alcalin: caracterisation physicochimique et retraitement electrochimique. In Metal 95, Proceedings of the International Conference on Metals Conservation, Semur en Auxois, September 25–28, eds. I. MacLeod, S. Pennec, and L. Robbiola, 170-177. London: James and James.

González, N., P. de Viviés, M. Drews, and P. Mardikian. 2003. Characterizing the chloride in the wrought iron rivets from the Hunley. NACE Northern Area Eastern Conference, September 15–17. Ottawa: Preservation of Heritage Artifacts.

Carlin, W., D. Keith, and J. Rodriguez. 2002. Galvanic removal of metallic wrought iron from marine encrustations. International Journal of Nautical Archaeology 31 (2): 293-299.

González, N., P. de Viviés, M. Drews, and P. Mardikian. 2004. Hunting free and bound chloride in the wrought iron rivets from the American Civil War submarine H. L. Hunley. Journal of the American Institute for Conservation 43 (2): 161-174.

Carpenter, J. 2005. Personal communication. The Western Australian Museum, c/o the Shipwreck Galleries, Cliff St., Fremantle, Western Australia.

Daniels, V.D., L. Holland, and C. Pascoe. 1979. Gas plasma reactions for the conservation of antiquities. Studies in Conservation 24: 85-92.

González, N., D. Cook, P. de Viviés, M. Drews, and P. Mardikian. 2007. The effects of cathodic polarization, soaking in alkaline solutions and subcritical water on cast iron corrosion products. In Metal 07, Interim Meeting of the ICOM-CC Metal WG, Amsterdam, 17–21 September 2007, eds. C. Degrigny, R. Van Langh, I. Joosten, and B. Ankersmit, 32-37. Amsterdam: Rijksmuseum.

Degrigny, C., and L. Spiteri. 2004. Electrochemical monitoring of iron artifacts during their storage/stabilization in alkaline solutions. In Metal 2004, Proceedings of the International Conference on Metals Conservation, Canberra, Australia, 4–8 October, eds. J. Ashton and D. Hallam, 315-331. Canberra: National Museum of Australia.

Häyhä, H. 1999. The history of iron protection: description of materials and evaluation of their properties. The Baltic Nordic Conference on Conserved and Restored Works of Art, 6–9 October 1999, Tallinn, Estonia. http://www.kanut.ee/toimetised/konverentsid/consasinve st/hayha.rtf (accessed June 2009).

de Viviés, P., D. Cook, M. Drews, N. González, P. Mardikian, and J.-B. Memet. 2007. Transformation of akaganeite in archaeological iron artifacts using subcritical treatment. In Metal 07, Interim Meeting of the ICOM-CC Metal WG, Amsterdam, 17–21 September 2007, eds. C. Degrigny, R. Van Langh, I. Joosten, and B. Ankersmit, 26-30. Amsterdam: Rijksmuseum.

Jakobsen, T. 1988. Iron corrosion theories and the conservation of archaeological iron objects in the 19th century with emphasis on Scandinavian and German sources. In Early Advances in Conservation, ed. V. Daniels, 51-58. London: British Museum.

Dalard F., Y. Gourbeyre, and C. Degrigny. 2002. Chloride removal from archaeological cast iron by pulsating current. Studies in Conservation 47: 117-121.

Keene, S. 1994. Real-time survival rates for treatments of archeological iron. In Ancient & Historic Metals: Conservation and Scientific Research, eds. D. Scott, J. Podany, and B. Considine, 249-264. Marina del Rey, CA: Getty Conservation Institute.

Drews, M.J., M. Barr, and M. Williams. 2000. A kinetic study of the SCWO of a sulfonated lignin waste stream. Industrial and Engineering Chemistry Research 39: 4784-4793.

Knight, B. 1997. The stabilization of archaeological iron: past, present, future. In Metal 95, Proceedings of the International Conference on Metals Conservation, Semur en Auxois, September 25–28, eds. I. MacLeod, S. Pennec, and L. Robbiola, 36-40. London: James and James.

Drews, M.J., M. Williams, and M. Barr. 2000. The corrosion of Sol–Gel-coated type 316 SS in chlorinated SC water. Industrial and Engineering Chemistry Research 39: 4772-4783. Drews, M., P. de Viviés, N. González, and P. Mardikian. 2004. A study of the analysis and removal of chloride in samples from the Hunley. In Metal 2004, Proceedings of the International Conference on Metals Conservation, Canberra, Australia, 4–8 October, eds. J. Ashton and D. Hallam, 247-260. Canberra: National Museum of Australia.

Loeper-Attia, M., and W. Weker. 1995. Dechloruration d’objets archeologiques en fer par la methode du sulfite alcalin a l’IRRAP. In Metal 95, Proceedings of the International Conference on Metals Conservation, Semur en Auxois, September 25–28, eds. I. MacLeod, S. Pennec, and L. Robbiola, 162-166. London: James and James.

Gilberg, M. 1987. Friedrich Rathgen: The father of modern archaeological conservation. Journal of the American Institute for Conservation 26 (2): 105-120.

Logan, J. 1989. The longest treatment in the history of the CCI. CCI Newsletter: 4-6 93

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Mardikian, P. 2004. Conservation and management strategies applied to post-recovery analysis of the American Civil War submarine H.L. Hunley (1864). The International Journal of Nautical Archaeology 33 (1): 137-148.

gaps in current knowledge. In Metal 2004, Proceedings of the International Conference on Metals Conservation, Canberra, Australia, 4–8 October, eds. J. Ashton and D. Hallam, 294-306. Canberra: National Museum of Australia.

Mardikian, P., M. Drews, N. González, and P. de Viviés. 2004. H.L Hunley conservation plan. Draft submitted to the US Naval Historical Center, Washington, DC, for peer review.

Selwyn, L., and J. Logan. 1993. Stability of treated iron: a comparison of treatment methods. Preprints of the ICOM Committee for Conservation 10th Triennial Meeting, Washington, DC. Paris: ICOM.

Mathias, C., K. Ramsdale, and D. Nixon. 2004. Saving archaeological iron using the Revolutionary Preservation system. In Metal 2004, Proceedings of the International Conference on Metals Conservation, Canberra, Australia, 4–8 October, eds. J. Ashton and D. Hallam, 28-42. Canberra: National Museum of Australia.

Turgoose, S., C. Hawkins, N. Wrathall, N. Kalbeek, J. van Lanschot, T. Mathiesen, and A. Sjogren. 1996. Development of improved conservation procedures for archaeological iron. Environment Program CT94-0561. Corrosion and Protection Center: UMIST and School of Conservation, Copenhagen.

McCarthy, M. 2000. Iron and Steamship Archaeology. Success and Failure on the SS Xantho. New York: The Plenum Series in Underwater Archaeology.

Watkinson, D. 1996. Chloride extraction from archaeological iron: comparative treatment efficiencies. In Archaeological Conservation and its Consequences, eds. A. Roy and P. Smith, 208-212. London: IIC.

North, N. 1978. Electrolysis of marine cast iron. Papers from the First Southern Hemisphere Conference on Maritime Archaeology, 145-147.

Watkinson, D. 2004. SS Great Britain iron hull: modeling corrosion to define storage relative humidity. In Metal 2004, Proceedings of the International Conference on Metals Conservation, Canberra, Australia, 4–8 October, eds. J. Ashton and D. Hallam, 89-102. Canberra: National Museum of Australia.

North, N., and C. Pearson. 1975. Alkaline sulfite reduction treatment of marine iron. Preprints of the ICOM Committee for Conservation 4th Triennial Meeting, Venice 1–13 October. Paris: ICOM.

Biographies Paul Mardikian received his MA in archaeology and art history from the School of the Louvre in Paris in 1989 and his MS in conservation sciences and techniques from the Sorbonne University in 1991. Paul’s experience in the field of maritime archaeology and conservation ranges from ancient shipwrecks in the Mediterranean to the conservation of artifacts from the RMS Titanic. He currently serves as the head conservator for the Clemson Conservation Center and Hunley Project.

North, N., and C. Pearson. 1977. Thermal decomposition of FeOCl and marine cast iron corrosion products. Studies in Conservation 22: 146-157. North, N., and C. Pearson. 1978. Methods for treating marine iron. In ICOM Committee for Conservation 5th Triennial Meeting, Zagreb, 1–10 October. Paris: ICOM. North, N., M. Owens, and C. Pearson. 1976. Thermal stability of cast and wrought marine iron. Studies in Conservation 21: 192-197.

Néstor González-Pereyra received his BS in chemistry in 1996 and graduated in 2002 in chemical engineering from the Universidad de la Republica in Uruguay. He is currently working as a research engineer at the Clemson Conservation Center developing subcritical and supercritical fluids applications in the field of archaeological conservation. He is enrolled in the PhD program at the School of Materials Science and Engineering at Clemson University.

O’Guinness Carlson, M., M. Bruce, and W. Riess. 2003. The Nottingham Galley cannon collection ca.1710: A proposed scientific inquiry into the reasons a conserved iron cannon dramatically cracked into pieces in storage. NACE Northern Area Eastern Conference. Ottawa: Preservation of Heritage Artifacts. Pearson, C. 1987. Conservation of Marine Archeological Objects. London: Butterworths.

Schmidt-Ott, K., and V. Boissonnas. 2002. Low-pressure hydrogen plasma: an assessment of its application on archaeological iron. Studies in Conservation 47: 81-87.

Michael J. Drews received his BS degree in chemistry from the University of Wisconsin at Madison and his PhD in physical chemistry from the University of North Texas. He is currently the director of the Clemson Conservation Center. His research interests include the corrosion and conservation of iron artifacts as well as the use of dense gas fluids in the conservation of nonmetallic artifacts from marine sites.

Selwyn, L. 2004. Overview of archaeological iron: the corrosion problems, key factors affecting treatment, and

Philippe de Viviés graduated in 1992 as a metallurgist specializing in heat treatment processes. In 2001, he

Rathgen, F. 1898. Die Konservierung Altertumsfunden. Berlin: W. de Gruyter.

von

94

PAUL MARDIKIAN, NÉSTOR G. GONZÁLEZ, MICHAEL J.DREWS, AND PHILIPPE DE VIVIES: NEW PERSPECTIVES received his MS in conservation sciences and techniques from the Sorbonne University. Philippe worked as a conservator on the Hunley Project for seven years and is now working with A-CORROS Expertise in France. Addresses Paul Mardikian* Clemson Conservation Center Warren Lasch Laboratory School of Materials Science Clemson University 1250 Supply Street, Bldg. 255 North Charleston, SC 29405 USA

and

Engineering

Néstor González Address same as for Mardikian Michael Drews Address same as for Mardikian Phillipe de Viviés A-CORROS Expertise Conservation-Restauration 23 Chemins des moines 13200 Arles France *Author to whom correspondence should be addressed.

95

CONSERVATION OF WATERLOGGED CORK USING SUPERCRITICAL CO2 DRYING Michael J. Drews, Jessica Green, Jason Hemmer, Philippe de Viviés, Néstor G. González, and Paul Mardikian Abstract Archaeological cork has often been reported to be very difficult to conserve because polyethylene glycol (PEG) and other consolidants generally do not readily penetrate the pore structure as they do in very degraded wood. The objective of the work reported in this paper was to evaluate the use of supercritical drying for the conservation of waterlogged corks. The cork samples employed in this study were from the Machault, a French ship scuttled in 1760 in Chaleur Bay during the battle of Restigouche and excavated by Parks Canada. The supercritical CO2 drying procedure employed was modeled after one previously reported in the literature. The process involves exchanging the water with methanol followed by extraction of the methanol using supercritical CO2. The results from the supercritical drying are compared to air-dried and freeze-dried samples.

Experimental specimens Parks Canada provided eight cork specimens obtained from the site of the Machault, a French ship that was scuttled on July 8, 1760, in Chaleur Bay during the battle of Restigouche. The Machault sank at the mouth of the Restigouche River, so the underwater environment was brackish water. All the corks were kept in tap water following their excavation by Parks Canada in the early 1970s. The first few years they were kept at room temperature and were exposed to light. From the early 1980s until their shipment to the Warren Lasch Conservation Center in Charleston, South Carolina, prior to treatment, they were kept in the dark and were refrigerated at 3–5°C. Description of supercritical drying A supercritical fluid is any fluid above its critical temperature and pressure. Supercritical fluids have solvating power like a liquid and exhibit transport properties between those of liquids and gases. One additional useful property of a supercritical fluid is the absence of interfacial tension. The absence of interfacial tension allows for the elimination of drying stresses resulting from capillary forces and surface tension during drying. The most common fluid employed for supercritical drying is carbon dioxide because it is relatively inert, readily available, non-toxic, inexpensive, and has an easily accessible critical point of 31°C and 73.8 bar. In fact, SC-CO2 processes are commercially viable on a very large scale as illustrated by the decaffeination of coffee (McHugh and Krukonis 1994). Some of the potential advantages of SC-CO2 drying as compared to other approaches to drying cork are (1) no consolidant is needed, (2) it is a reversible process in the sense that no chemical changes are induced in the artifact, (3) it is very fast relative to the alternative treatments, (4) it can readily be extended to very large pieces with the proper engineering of the process, and (5) all chemicals can, in theory, be easily recycled.

Introduction The successful conservation of organic materials recovered from wetland or marine environments always involves one critical step, the drying of the artifact (Grattan 1982; Jenssen 1987; Kaye et al. 2000). This step is especially critical to wood and cork because the cellular wall structure has generally been weakened, making them very susceptible to collapse from drying stresses. While there is extensive literature on the successful treatment of waterlogged wood, there has been relatively little published on cork. In fact, cork has been reported to be relatively difficult to conserve (Jenssen 1987; Smith 1998). This difficulty has been attributed to the impermeability of the cork to consolidants (Jenssen 1987; Kaye et al. 2000). The discovery of six canteen stoppers during the excavation of the H. L. Hunley submarine (sunk in 1864 off the coast of Charleston, South Carolina), and the necessity to explore the potential of a less risky treatment than what is currently available for cork, provided the impetus for a new investigation of the methods available to stabilize this material.

The supercritical fluid drying process involves two distinct steps: water exchange with the appropriate organic solvent, and the drying step that involves the removal of the solvent under supercritical conditions. In the first step, because water with a surface tension of 73 dynes/cm is not soluble in SC-CO2, it is exchanged out with a low surface tension solvent (about 20–30 dynes/cm) that is very soluble or miscible with SC-CO2. In the critical point drying of small biological specimens, the two common exchange solvents are ethanol (23 dynes/cm) and acetone (24 dynes/cm). In the SC-CO2 drying research of waterlogged archaeological specimens that has been published, the solvent most commonly employed has been methanol (23 dynes/cm). In addition, above 50°C and 95 bar, methanol and SC-CO2 are completely miscible (Kaye et al. 2000).

A relatively new method for preserving waterlogged wood and cork involves the use of supercritical carbon dioxide (SC-CO2) drying. The results of using SC-CO2 drying on more than 150 samples of wood have been reported (Chaumat et al. 1997; Coeuré et al. 1998; Kaye et al. 2000; Teshirogi et al. 2001). However, only two cork samples have previously been treated using this technique (Kaye et al. 2000). The primary objective of this investigation was to compare the results from the SC-CO2 drying of waterlogged cork specimens to the airdrying of a control sample. In order to provide a more quantitative comparison of the results, the anti-shrink efficiency (ASE) was calculated for each treated specimen (Grattan et al. 1980).

97

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS laboratory sample identification numbers is shown in Fig. 1. Four of the specimens were essentially intact and four were only parts of corks. The preliminary SC-CO2 drying experiments were carried out using specimens WL-0400, WL-0402, WL-0403, and WL-0404. After the methanol exchange was completed, WL-0400 and WL0403 were dried together and then WL-0402 and WL0404 were dried together. Expression (1) was used to calculate the moisture content of each based on the initial wet weight and the final weight after SC-CO2 drying.

In the drying step of the process, the low surface tension solvent is removed by ‘extraction’ with a stream of SCCO2, leaving the ‘dried’ specimen. Because there is no change in the phase of the solvent being removed during this step, no or very small drying forces are generated. Water exchange protocol and supercritical fluid drying for cork and wood The SC-CO2 drying procedure employed for the cork specimens was adapted to the available equipment from that published in the literature (Kaye et al. 2000). In the first step, the water was exchanged out using anhydrous methanol. Each specimen was soaked in 250 ml of anhydrous methanol in a closed 500 ml polypropylene wide-mouth bottle supported about 1 cm above the bottom on a PFA strainer, sieve 0.5 mm mesh for one week. After one week the methanol was exchanged with new solvent. Each specimen was subjected to three solvent changes. During the last week of soaking, 20 gm of anhydrous sodium sulfate was added to the container. The specimens were weighed and measured at each solvent change and before the final drying step.

% Moisture =

(1)

The moisture contents of specimens WL-0400, WL0402, WL-0403, and WL-0404 were calculated to be 685%, 590%, 740%, and 540%, respectively.

The equipment utilized for the SC-CO2 drying consisted of a Thar Technologies 250 ml stirred high pressure reactor capable of operating up to 300 bar at 150°C. The system pressure was maintained using a Thar Technologies ABPR-20 Programmable BPR (back pressure regulator) and the fluid flow controlled using a Teledyne ISCO Model 260D Syringe Pump chilled to 10°C. The liquid CO2 was supplied at about 55 bar from a high pressure cylinder of SFC grade CO2. Approximately 50 ml anhydrous methanol was added to the bottom of the Thar vessel. The specimens were wrapped in TX 1009 Alpha wipes saturated with anhydrous methanol and placed into the Thar vessel in a basket fabricated from 20 mesh stainless steel screen. The vessel was filled with liquid CO2 (about 55 bar), heated to 50°C, brought to final pressure of 120 bar and the ISCO flow rate set at 0.3 ml/min. The drying step was continued until no additional methanol was collected at the ice bath trap at the restrictor vent. At the conclusion of each drying run, the chamber was slowly depressurized at a controlled rate of 20 bar/hr for 6 hrs using a script that was custom written for the backpressure regulator.

Figure 1: Photograph of the eight cork specimens from the Machault as received from Parks Canada.

Percent shrinkages were calculated based on measurements of the dimensions of the corks before and after drying. For these four samples, only the length and the diameter at the widest dimension were recorded. These data along with the calculated percent shrinkages are summarized in Table 1. No change greater than 3.3% was observed along any of the measured dimensions. Compared to other treatment methods, such as the results reported for a set of corks treated by the silicone oil technique (Smith 1998), the shrinkage observed for SCCO2 dried specimens was significantly less and much more isotropic from one cork sample to the other.

Results and discussion on cork stabilization using supercritical fluids A photograph of the eight cork specimens from the Machault, as received from Parks Canada, and their Specimen WL-0400 WL-0402 WL-0403 WL-0404 WL-0404(2)

(2)

Initial ( wt ) − Final ( wt ) x100 Final ( wt )

Initial L, mm

Final L, mm

% Change

22.8 20.2 21.0 39.2

22.3 19.6 20.3 39.2

−2.2 −3.0 −3.3 0.0

Initial W, mm 23.9 21.0 19.9 23.1 21.6

Final W, mm 23.4 20.9 19.4 22.8 21.2

Bottom of specimen

Table 1: Changes in cork dimensions (length and width) for the initial SC-CO2 drying experiments.

98

% Change −2.1 −0.5 −2.5 −1.3 −1.8

MICHAEL J. DREWS

ET AL: CONSERVATION OF WATERLOGGED CORK USING SUPERCRITICAL CO2 DRYING

WL-0398

W eig h t, g

9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 -

air drying oven

-

2

4

6

8

10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46

Time, days Figure 2: Mass loss versus time for the air-dried and oven-dried specimen WL-0398.

−0.208 g. The change in weight plotted as a function of soaking time for specimens WL-0397, WL-0399, and WL-0401 is shown in Fig. 3. The weight of the specimens decreases significantly over the first 14 days and then appears to become relatively constant. This suggests that the methanol exchange was relatively complete after the second solvent change and that the specimens could have been SC-CO2 dried at this point. After the methanol exchange was completed, WL-0397, WL-0399, and WL-0401 were SC-CO2 dried at the same time. Moisture contents of specimens WL-0397, WL0399, and WL-0401 were calculated to be 870%, 368%, and 724%, respectively.

For the second set of drying experiments, one of the specimens was air dried so that the anti-shrink efficiency (ASE) could be calculated. Specimen WL-0398 was selected to be air dried. In addition, in order to obtain more precise dimensions, measurements pins were inserted into WL-0398 and WL-0399 prior to treatment. The plot of weight versus time for the air-dried specimen WL-0398 is shown in Fig. 2. Even though the mass loss appeared to have stabilized after approximately 10 days, room temperature drying was continued for another 13 days and then the sample was placed in an oven at 70°C to ensure that drying was complete. The moisture content of WL-0398 was calculated to be 343%, which was significantly lower than had been observed for the four specimens previously dried using SC-CO2 drying (540 to 740%). This would suggest that this specimen was not as degraded and could account for the relatively short time needed for the air-drying.

For specimens WL-0397 and WL-0401, only the length and the diameter at the widest dimension were recorded; this data along with the calculated percent shrinkages are summarized in Table 2. In the first set of drying experiments (5 specimens), no change of greater than 2.5% was observed along any of the measured dimensions. In this set (2 specimens), slightly more shrinkage was observed: overall ~4% with a maximum of 7.3%. However, part of this difference may be attributed to the fact that the final measurements were made with a slightly less precise caliper (±0.1 mm) than had previously been employed (±0.01 mm). Unfortunately, it was not possible to redo these measurements using the original caliper. Nevertheless, compared to the results reported for a set of corks treated by the silicone oil technique (Smith 1998), the shrinkage observed for these three SC-CO2 dried specimens was still significantly less and much more isotropic from one cork sample to the other.

12

10

Weight, g

8 W L-0397

6

W L-0399 W L-0401

4

2

0 5/28/05

6/7/05

6/17/05

6/27/05

7/7/05

7/17/05

Figure 3: Change in specimen weight as a function of soaking time in methanol.

In addition to the length and width measurements, pins were inserted into samples WL-0398 (air-dried control) and WL-0399 (SC-CO2 drying treatment) for determination of ASE. The results from these two specimens are compared in Table 3. Again, the actual percent shrinkages measured for specimen WL-0399

Because the density of methanol at 25°C is only 0.792 g/cc, it is possible to monitor the progress of the exchange process by measuring the weight of the specimens. For each gram of water displaced by methanol, the specimen weight should decrease by 99

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS moisture content and presumably may not have been as severely degraded as some of the other specimens.

were all less than 3.5%. If an ASE of 75 or above is considered acceptable for cork, as has been proposed for wood (Grattan 1980), the SC-CO2 drying of WL0399 could be considered a very successful treatment

Photographs of WL-0398 and WL-0399 before and after treatment are shown in Fig. 4. A significant distortion is obvious in the air-dried specimen WL-0398 while none is apparent in the SC-CO2 dried specimen WL-0399. WL-0399 is typical of all the cork specimens before and after SC-CO2 treatment: no evidence of movement is visible. Their diagnostic features are well preserved and enhanced by the treatment. Finally, the treated samples are structurally sound and their color and weight pleasing and natural.

Using the data presented in Tables 1 through 3, the ASE for the length dimension for all of the treated specimens can be calculated. As shown in Table 4, the calculated ASE values range from a low of 40 to a high of 100, with an average of 73. It must be emphasized at this point that the ASE evaluation is very sensitive when used on such small samples and the interpretation of the results should be taken cautiously. In addition, they were calculated on the basis of air drying a specimen that had the lowest Specimen

Initial L, Final L, mm % Change Initial W, Final W, mm mm Mm WL-0397 31.7 30.7 −3.2 ----Top-Narrow ------15.4 14.7 Top-Wide ------17.6 16.4 Bottom-Narrow ------15 14.5 Bottom-Wide ------19.1 18.5 WL-0401 10.5 9.8 −6.7 ----Top-Narrow ------25.2 24.1 Top-Wide ------23.7 23.7 Table 2: Changes in length and width of WL-0397 and WL-0401 in the SC-CO2 drying experiments. (1)

Direction

Sample

initial (waterlogged sample)

Final (treated or air dried sample)

Shrinkage (%) - referred to the initial values

WS-398 (control)

16.4

15.5

5.5%

WS-399 ( treatment)

25.7

25.9

-0.8%

WS-398 (control)

7.8

7

10.3%

WS-399 ( treatment)

15.2

14.7

3.3%

WS-398 (control)

12

11.1

7.5%

WS-399 ( treatment)

12

12.1

-0.8%

WS-398 (control)

35

31.1

11.1%

WS-399 ( treatment)

37.1

36.1

2.7%

WS-398 (control)

16.9

12.9

23.7%

WS-399 ( treatment)

23.3

22.8

2.1%

WS-398 (control)

16.9

12.9

23.7%

WS-399 ( treatment)

20.8

20.7

0.5%

PL

% Change --−4.5 −7.3 −3.3 −3.1 --4.4 0.0

ASE 114

PR

68

PT

111

L

76

Ta

91

Tb

98

(1)

PL = distance between pins in the length direction; PR = distance between pins in the radial direction, bottom; PT = distance between pins in the tangential direction, bottom; L = distance between top and bottom; Ta = top width, widest dimension; Tb = top width, narrowest dimension.

Table 3. Dimension data used to calculate ASE for specimen WL-0399. WL-0397 WL-0399 WL-0400 WL-0401 WL-0402 % H2O 870 368 685 724 590 ASE 71 76 80 40 73 Table 4. Comparison of ASE values along the length of the SC-CO2 dried specimens.

100

WL-0403 740 70

WL-0404 540 100

MICHAEL J. DREWS

ET AL: CONSERVATION OF WATERLOGGED CORK USING SUPERCRITICAL CO2 DRYING

the long term ‘stability’ of SC-CO2 dried specimens will be as compared to others conserved using different types of treatment also still needs to be determined. Acknowledgements The authors would like to thank the State of South Carolina (Hunley Commission), the Friends of the Hunley, and Clemson University’s School of Materials Science and Engineering for supporting this research. We would like to thank Ms. Kim Ivey and Mr. Gaël Combernous of Clemson’s School of Materials Science and Engineering and all the personnel of the Clemson Conservation Center at the Warren Lasch Laboratory for their assistance and contributions to the study. We are especially indebted to Parks Canada’s Ms. Marthe Carrier, conservator, and Mr. Charles Bradley, material culture researcher, for providing the cork specimens employed in this study.

Figure 4: Photographs of WL-0398 (air drying) and WL-0399 (SC-CO2 drying) before and after treatment.

Summary and conclusions In published reports, only two cork samples have previously been treated using SC-CO2 drying (Kaye et al. 2000) but no dimensional data were reported for these samples. The objective of this investigation was to compare the results from the SC-CO2 drying of seven waterlogged cork specimens to the air drying of a control sample. For a more quantitative comparison of the results of the SC-CO2 drying, the anti-shrink efficiencies were calculated for selected specimens.

References Chaumat, G., Q. Tran, C. Perre, and G. Lumia. 1997. Trials of shape recovering from collapsed waterlogged wood by treatment with CO2 supercritical fluid. In Proceedings of the 7th ICOM Group on Wet Organic Archaeological Materials Conference, Grenoble, eds. C. Bonnot-Dicone, X. Hiron. Q. Tran, and P. Hoffmann, 137-143. Grenoble: Arc-Nucleart. Coeuré, P., G. Chaumat, Q. Tran, and C. Perre. 1998. Die konservierung von naßholz; versuche mit polethyleneglykol on superkritischer kohlendioxidflussigkeit. Arbeitsblätter für Restauratoren, Gruppe 8, Holz 31(1): 266-269.

In this study, waterlogged cork specimens (368 to 870% water) were treated using a SC-CO2 drying process. In general, the observed shrinkage that occurred in all of the cork specimens in all directions ranged from 2% to 4%. ASE values ranged from 68 to 114. However, it should be noted that that the ASE evaluation is very sensitive when used on such small samples and the interpretation of the results should be taken cautiously. In addition, they were calculated on the basis of air drying a specimen that had the lowest moisture content and presumably may not have been as severely degraded as some of the other specimens. It is not possible to say at this time that the ASE values above 100 were due to cork expansion as a result of the formation of cracks.

Cook, C., and D. Grattan. 1991. A method for calculating the concentration of PEG for freeze-drying waterlogged wood. In Proceedings of the 4th ICOM Group on Wet Organic Archaeological Materials Conference, Bremerhaven, ed. P. Hoffmann, 239-251. Bremerhaven: Deutsches Schiffahrtsmuseum. Grattan, D. 1982. A practical comparative study of several treatments for waterlogged wood. Studies in Conservation 27: 124-136.

Photographs taken before and after SC-CO2 drying show no obvious evidence of movement in the cork specimens. In all of the specimens, the diagnostic features are well preserved and enhanced by the treatment. The SC-CO2 dried specimens are structurally sound and their weight and color pleasing and natural.

Grattan, D. 1987. Waterlogged wood. In Conservation of Marine Archaeological Objects, ed. C. Pearson. London: Butterworths. Grattan, D., and R. Clarke. 1987. Conservation of waterlogged wood. In Conservation of Marine Archaeological Objects, ed. C. Pearson. London: Butterworths.

The results of this study confirm that heavily waterlogged cork can be successfully dried without the use of consolidants using a SC-CO2 drying process. Finally and most importantly, it was also concluded that from a conservation standpoint this treatment was successful.

Grattan, D.W., J. McCawley, and C. Cook. 1980. The potential of the Canadian winter climate for the freezedrying of degraded waterlogged wood. Studies in Conservation 25: 118-136.

Additional studies suggested by the results of this research include one to determine at what degree of degradation (i.e., water content) a given artifact can be treated without requiring the use of a consolidant. What

Jenssen, K. 1987. Conservation of wet organic artifacts excluding wood. In Conservation of Marine

101

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Nestor Gonzalez-Pereyra received his BS in chemistry in 1996 and graduated in 2002 in chemical engineering from the Universidad de la Republica in Uruguay. He is currently working as a research engineer at the Clemson Conservation Center developing sub and supercritical fluids applications in the field of archaeological conservation. Nestor is enrolled in the PhD program at the School of Materials Science and Engineering at Clemson University.

Archaeological Objects, ed. C. Pearson. London: Butterworths. Kaye, B., D. Cole-Hamilton, and K. Morphet. 2000. Supercritical drying: a new method for conserving waterlogged archaeological materials. Studies in Conservation 45: 233-252. McHugh, M., and V. Krukonis. 1994. Supercritical Fluid Extraction, 2nd ed. Boston: Butterworth-Heinemann.

Paul Mardikian received his MA in archaeology and art history from the School of the Louvre in Paris in 1989 and his MS in conservation sciences and techniques from the Sorbonne University in 1991. Paul’s experience in the field of maritime archaeology and conservation ranges from ancient shipwrecks in the Mediterranean to the conservation of artifacts from the RMS Titanic. He currently serves as the head conservator for the Clemson Conservation Center and Hunley Project.

Smith, C. 1998. Silicone bulking of waterlogged cork using PS340, PS341 and PS 343 silicone oils. Archaeological Preservation Research Laboratory (APRL) Report 7, http://nautarch .tamu.edu/aprl/report07.pdf (accessed June 2009). Teshirogi, M., E. Tahata, M. Kikuchi, H. Inomata, Y. Kohdzuma, T. Koezuka, and M. Sawada. 2001. Conservation treatment of water-logged wood with supercritical carbon dioxide. In Proceedings of the 8th ICOM Group on Wet Organic Archaeological Materials Conference, Stockholm, eds. P. Hoffmann, J. Spriggs, T. Grant, C. Cook, and A. Recht, 371-377. Bremerhaven: Deutsches Schiffhartsmuseum.

Addresses Michael Drews*, Jessica Green, Jason Hemmer, Néstor G. González, and Paul Mardikian Clemson Conservation Center Warren Lasch Laboratory School of Materials Science and Engineering Clemson University 1250 Supply Street, Bldg. 255 North Charleston, SC 29405 USA

Biographies Michael J. Drews received his BS degree in chemistry from the University of Wisconsin at Madison and his PhD in physical chemistry from the University of North Texas. He is currently the director of the Clemson Conservation Center and professor emeritus in the School of Materials Science and Engineering at Clemson University. His research interests include the corrosion and conservation of iron artifacts as well as the use of dense gas fluids in the conservation of non-metallic artifacts from marine sites.

Phillipe de Viviés A-CORROS Expertise Conservation-Restauration 23 Chemins des moines 13200 Arles France *Author to whom correspondence should be addressed.

Jessica Green is a graduate student in polymer and fiber science in the School of Materials Science and Engineering at Clemson University. She is a graduate research assistant in the School of Materials Science and Engineering and has been an active contributor to several other research projects in addition to the SC-CO2 drying study. Jason Hemmer graduated from Worcester Polytechnic Institute in 2002 with a BS degree in biomedical engineering. From there he began graduate work in the Department of Bioengineering at Clemson University. He completed his master’s degree in bioengineering in 2005, investigating the use of supercritical fluids for biomedical sterilization procedures and is currently pursuing his doctorate in bioengineering at Clemson University. Philippe de Viviés graduated in 1992 as a metallurgist specializing in heat treatment processes. In 2001, he received his MS in conservation sciences and techniques from the Sorbonne University. Philippe worked as a conservator on the Hunley Project for seven years and is now working with A-CORROS Expertise in France. 102

DOCUMENTING MONGOLIA’S DEER STONES: APPLICATION OF 3D LASER SCANNING TECHNOLOGY TO ARCHAEOLOGICAL CONSERVATION Basiliki Vicky Karas, Harriet F. Beaubien, and William W. Fitzhugh Abstract The steppes of northern Mongolia are populated by over 550 ancient stone sculptures characterized by low-relief carved images of highly stylized deer. These so-called ‘deer stones’ are considered to be among Central Asia’s most significant archaeological treasures. Yet, systematic recording, archaeological investigation, and the implementation of preservation strategies have been limited, in part, by the deer stones’ geographic isolation within a harsh environment. As a result, Mongolia’s deer stones present an extreme case of cultural heritage at risk. As such, they provided an excellent opportunity for conservators from the Smithsonian Museum Conservation Institute (MCI) to test pilot non-contact 3D laser scanning technology as a documentation and preservation tool. In the summer of 2005, the Smithsonian Institution’s Deer Stone Project in Mongolia field-tested a portable, hand-held 3D laser scanner; the project’s goals, procedures and results are presented, and the exciting potential for 3D laser scanning technology within the field of archaeological conservation is discussed.

Archaeological conservators from the Smithsonian Museum Conservation Institute (MCI) recently had the opportunity to apply 3D laser technology in such circumstances. Little known in Western scholarship, hundreds of remarkably carved ancient monoliths referred to as deer stones are found throughout Mongolia’s northern steppe and Altay mountain region (Jacobson-Tepfer 2001). Their deteriorating condition and limited documentation presented an opportunity to field-test a portable hand-held 3D laser scanner as a documentation and preservation tool. This pilot project was carried out in the summer of 2005 as part of the Joint Mongolian-Smithsonian Deer Stone Project (DSP), which is investigating northern Mongolia’s connections to arctic cultural history. Among the project priorities is the preservation of the deer stones through archaeology, iconographic study and conservation efforts.1 The deer stones Mongolia’s northern steppe is home to over 550 of the approximately 700 known examples of deer stones; upright stone slabs ornamented with low relief carving dominated by images of deer in ‘synchronized flight’ (Baiarsaikhan 2004; Jacobson 1984) (Fig. 1). The stones are predominantly granite, with some basalt and other examples; they average 1 to 3 meters in height and are almost always carved on four sides. The deer stones are found alone, in small groups or concentrated in larger groupings in grassy steppe environments, often in association with stone khirigsuur burial complexes. These monoliths have been dated to the Late Bronze to Early Iron Age (2000–3000 years BP),2 and are the primary record of people living in the steppe region at a time when nomadic pastoralism had replaced a more sedentary lifestyle (Frohlich et al. 2004; Fitzhugh 2005).

Introduction The application of 3D laser imaging to heritage preservation is changing the way that cultural objects and sites are documented, monitored, studied and enjoyed. From its use in the study of the ancient monoliths at Stonehenge to transfiguring Michelangelo’s David into the virtual reality of the third millennium, 3D laser scanning has inspired archaeologists and conservators to look at cultural heritage in a different light (Goskar et al. 2003; Levoy et al. 2000). The scientific literature of the past five years has demonstrated the enormous potential for 3D lasers to contribute significantly to archaeological conservation research, preservation and education strategies (Mettenleiter et al. 2003; Ahmon 2004; Taylor et al. 2003; Godin et al. 2003; Beraldin et al. 2005; Chalmers et al. 2001). The increasing commercial availability of 3D laser systems designed and marketed for heritage applications is making this technology available to a broader audience. Portable and hand-held laser systems in particular are proving to be an excellent and reliable tool for the archaeological conservator.

The deer stones’ proximity to burial complexes and their decorative schemes have led researchers to characterize them as guardian or warrior stones, possibly meant to represent male human figures that, in a ritual context, commemorate important personages (Kubarev 1979). Although only a few of the deer stones have facial 1 The DSP has carried out a collaborative research program in the Hovsgol Region since 2001. The project is coordinated by the Arctic Studies Center of the Smithsonian’s National Museum of Natural History (NMNH) in Washington, DC, under the direction of William W. Fitzhugh. In addition to NMNH, project partners now include the Smithsonian Museum Conservation Institute (MCI) in Suitland, MD, and in Ulaanbaatar, the National Museum of Mongolian History, the Mongolian Academy of Sciences, the Mongolian National University, and the American Center for Mongolian Studies. 2 Dates for the deer stones have been determined through iconographic study of weapons and tools carved on individual stones (JacobsonTepfer 2001). Additionally, test pits excavated in 2003–2004 around deer stones #4 and #5 at the site of Ulaan Tolgoi produced a series of radiocarbon dates between 2500 and 3000 BP, which corresponds to the Late Bronze Age/Early Iron Age (see Fitzhugh 2003, 2004).

By its very nature, archaeological conservation is often an exercise in triage. Environmental considerations, restricted access to objects or sites due to cultural, political or geographical obstacles, limited electricity and water, and the deadlines under which an archaeological team operates, demand a high level of creative problem solving and mobility from the conservator. Initially, lasers may seem an unlikely addition to the conservator’s toolkit in a field that requires constant accommodation to its less than ideal working conditions, and generally relies heavily on low-tech approaches to the complex problems of high-risk archaeological material. 103

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Since 2001, the DSP has undertaken archaeological and ethnographic research centered in the Hovsgol-Darkhat region that employs new techniques and theoretical approaches, building on nearly a century of art-historical and cultural studies by Mongolian, Soviet and American researchers (Fitzhugh 2005; Fitzhugh 2004). These studies seek to elucidate aspects of individual deer stones, including their age and context, as well as specific cultural aspects, such as death ritual and shamanism, that may provide insight into the deer stones’ imagery, meaning and function (Baiarsaikhan 2004; Bayarsaikhan 2005). Test excavations have also been carried out at a variety of deer stone sites as part of the archaeological investigations, which include an extensive survey and mapping program of ritual landscape features using high resolution GPS technology (Frohlich et al. 2004; Frohlich et al. 2005; Wallace and Frohlich 2005). Accurate plan maps have been produced for more than 500 khirigsuur complexes to date.

features, the majority display iconography which suggests an anthropomorphic scheme, such as earrings positioned high on opposite sides of the stone, and belts from which various tools and weapons hang (Baiarsaikan 2004) (Fig. 1). The greatest surface area of many of these stones is dominated by intriguing images of deer with flowing antlers, their faces modified with elongated snouts or the bills of water birds (Fig. 1). Some scholars have suggested that these depictions of deer portray the tattooing on a warrior’s body or reflect shamanistic representations of transformation beings or spirit helpers, whose purpose it is to ensure the memorialized individual’s safe passage into the afterlife (Jacobson 1993; Fitzhugh 2003). Still other theories describe the imagery as representing the embroidered ornaments embellishing a warrior’s clothing (Jacobson 1993).

The documentation program The DSP’s research program includes systematic recording of the deer stones, which is intended to supplement currently available resources. These are still somewhat limited in number and are variable in scope and level of detail. Several regional inventories of individual monuments have been published, which provide some descriptive information but are only selectively illustrated, primarily with line drawings (Sanjmyatov 1993; Volkov 2002). More recent scholarly publications, museum catalogues and locally produced educational products include high quality images of particular deer stones, although often of single sides and without indications of scale (Natsagbadam 2002; Tsultem 1989). Unfortunately, many records from Soviet-era archaeological investigations of deer stone sites, including notes, drawings and photographs related to the re-erection of monuments, remain inaccessible (Baiarsaikhan 2004). The limited and inconsistent documentation of these stones is of great concern, considering the environmental and human threats they face. Thousands of years of weathering in an isolated and climatically severe environment has resulted in surface deterioration and overall weakening of the stones. These degradations are evidenced in worn and spalled surfaces, and in the ubiquitous and unchecked encrustations of bird droppings and lichen growth (Fig. 2). Vandalism and theft are also significant concerns and both threaten to increase as Mongolia experiences more tourist traffic.

Figure 1: Deer stone #9 at the Ushkiin Uver site. Overall showing carved images of stylized deer and detail of lower portion carved with images of a belt, weapons and tools. Photo: H. Beaubien.

The striking iconography of these monuments has attracted scholarly attention, primarily in studies of Siberian and Eurasian artistic and cultural traditions, and particularly the origins of Scythian art (800–500 BC) (Jacobson 1993; Jacobson 2002). Yet, very little is understood about the deer stones’ age, function and meaning within their particular social, cultural, religious or artistic contexts. Geographic isolation has hampered local and scientific traditions of investigation, including systematic documentation and archaeological investigation. Further endangered by unprotected exposure to harsh environmental conditions and, increasingly, by human activity, the deer stones are now considered among the most important, and threatened, archaeological treasures of Central Asia.

Documentation, as part of the DSP, is intended to supplement detailed mapping and archaeological data from deer stone site investigations, and includes comprehensive photography with scale indications, drawings, condition notes, and for the first time, threedimensional records of individual deer stones, using both conventional and new approaches.

104

BASILIKI VICKY KARAS, HARRIET F. BEAUBIEN, AND WILLIAM W. FITZHUGH: DOCUMENTING MONGOLIA’S DEER STONES experienced model makers from the Smithsonian’s Office of Exhibits Central (OEC) produced a highquality mold using materials brought from the United States. A silicone rubber primary mold and a mother mold of expanding polyurethane foam were applied to the deer stone over a two-day period. A biodegradable soap solution served as a parting layer (Fig. 4). The mold was disassembled, brought back to OEC, and used to create two lightweight casts made of synthetic resins, which faithfully reproduced the surface details of the original. One cast was given to the National Museum of Mongolian History for display; the other was included in the Smithsonian’s National Museum of Natural History exhibition Modern Mongolia: Reclaiming Genghis Khan (June to December 2002), and is now in the collection (Fitzhugh 2003).

Figure 2: Unidentified deer stone in Hovsgol Aimag showing wear and damage from bird droppings. Photo: H. Beaubien.

Figure 4: Ushkiin Uver deer stone #14 shown with inner mold and outer jacket mold still in place. Photo: C. Thome.

This method was able to produce accurate documentation-to-scale reproductions of topographic and dimensional aspects. It was considered a relatively safe, simple and inexpensive procedure; however, imported materials and personnel training were necessary, and best results required an experienced model maker to accurately reproduce color and texture in a cast. The usual concerns with traditional molding and casting techniques, such as damage from the materials applied to the stone surface and mold separation, were addressed in choosing a suitably robust stone for this trial.

Figure 3: Deer stone #14 with carved human face at the Ushkiin Uver site. Photo: C. Thome.

Molding and casting A conventional mold-making technique was the first 3D method used by the DSP on a deer stone. The monument selected for the procedure was deer stone #14 at the site of Ushkiin Uver, a beautifully carved stone famous for its rare depiction of a human face and its great height (Fig. 3). In June 2002, a small team headed by

Laser scanning An alternative technique of creating 3D records of the deer stones, using laser scanning technology, was tested during the DSP’s field season in June–July 2005. The 105

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS the laser line with the surface. The camera in the wand detects the reflectance of each profile, and each point is individually located in 3D space using triangulation; the position of the laser-line generator and the sensor are fixed and known, and changes in surface shape are recorded through the varying angles of reflectance (Fig. 6).

laser scanning team consisted of two conservators from MCI (authors) and Carolyn P. Thome, one of the model makers who produced the Ushkiin Uver mold and casts discussed above. Partial and complete scans of twelve deer stones were carried out at Ushkiin Uver, Tsatstain Khoshun, Efd Valley and the Erkhel lake region, which includes locations at Ulaan Tolgoi, Erkhel North and Erkhel East. A 3D laser scanning system offers significant advantages over direct molding/casting, as dimensional and topographic information is rapidly and accurately recorded in digital format without directly contacting the surface. With 3D digital technology, any number of reproductions can be made without data degradation, in contrast to a mold’s limited reusability. The digital files themselves have a better long-term preservation prognosis than any other 3D documentation method, with storage on CD and migration to other digital media as needed. The digital files can be displayed graphically, to complement other forms of documentation. These files can also be exported to specialized milling machines to create high-resolution 3D models.

Figure 6: Diagram of triangulation between system components. Credit: B. Karas.

Methodology Equipment A Polhemus FastSCAN Cobra laser system was used for scanning. Its key components are the wand (range finder), the reference receiver, the transmitter and the processing unit (Fig. 5). The Polhemus software was run on a Hewlett-Packard Pentium IV computer. The computer and scanner were powered in the field by a Honda EU1000i generator developed specifically for use with precision equipment. Virtual manipulation of the 3D graphic models currently utalizes Rhinoceros and Flamingo modeling software.

Figure 5: Polhemus FastSCAN Cobra laser system components (left to right): wand (range finder) on top of the processing unit, reference receiver, and transmitter. Photo: B. Karas.

Scanning process The scanning phase requires only that the wand be moved in a controlled sweeping motion approximately 10 to 15 cm above an object’s surface. The wand projects and simultaneously detects laser light at a wavelength of 670 nm, through a centrally mounted, laser line generator and a miniature camera, at a scanning rate of 50 lines per second and a resolution of 0.5 mm (Polhemus 2001). A profile of the object’s surface, consisting of thousands of 3D coordinate points, is created at every intersection of

Figure 7: Raw data for Ulaan Tolgoi deer stone #5 (detail), displayed in various 3D graphic formats: (top) solid format; (middle) point cloud format; (bottom) wireframe format. Credit: B. Karas.

106

BASILIKI VICKY KARAS, HARRIET F. BEAUBIEN, AND WILLIAM W. FITZHUGH: DOCUMENTING MONGOLIA’S DEER STONES all possible values. Setting inappropriate values can result in either a blistered and obscured surface texture, which is time consuming to process, or at the other extreme, a very smooth surface that has almost no recognizable detail but can be processed in a very short time. It is possible to expedite a basic surface by using default numerical settings and bypassing the sweep editing and registration steps (described above). Doing this will provide a quick but significantly unrefined basic surface image.

Post-processing The triangulation process also relies on the transmitter, which generates magnetic fields in three directions. The amplitude of these fields determines the position and orientation of the receiver mounted in the wand, and the reference receiver if it is being used. Consequently, if the transmitter is acting as the fixed datum, then the computer locates each profile relative to the transmitter. When the reference receiver is attached to the object surface to serve as the fixed datum, the computer will locate each profile relative to the object. Using the reference receiver in this way makes it possible to move the object during scanning. The digitized 3D information conveyed by all these components is calculated by the processing unit and the computer, and simultaneously mapped by the laser software in graphic form for display in point-cloud, wire-frame, or solid 3D graphic formats (Fig. 7). Once the scanning is complete, the information contained in one of the above formats must go through a series of lengthy post-processing steps that translate the raw data into an exportable data format. With the Polhemus FastSCAN laser system these post-processing steps are applied manually by the operator; other laser systems are being designed to automatically post-process the raw data, which expedites the process significantly. These steps, discussed below, culminate in a digitally exportable product for use with 3D modeling software and computer numerical controlled (CNC) milling machines.

Figure 8: Basic surface (detail) before preliminary processing, for Ulaan Tolgoi deer stone #5, showing flaws and noise resulting from sweep overlap and light interference. Credit: B. Karas.

Step one: sweep editing and registration The manual operation of a hand-held laser system, combined with unpredictable field conditions, introduces the potential for flaws in the raw data, called ‘noise’. Noise results from accidentally scanning background objects, atmospheric light interference, and incomplete data collection from surfaces with high reflectance. A noisy digital surface will have a blistered appearance, which obscures details and renders the image unacceptable for further processing (Fig. 8). This noise is visible on the computer image during scanning and can be manually selected and removed during postprocessing. Sweep overlap inevitably occurs during scanning, producing an excess of points collected. This excess is not always obvious during scanning but translates as noise during surface processing. Post-processing steps provide a means to check each sweep in a file, view the degree of overlap and remove or reduce areas of overlap. When all manner of surface noise is eliminated or reduced to an acceptable level, a sweep registration step is initiated that improves sweep-to-sweep alignment and results in an integrated surface and better resolution.

Figure 9: Screen shot showing basic surface after postprocessing steps, for Efd Valley deer stone #1. Credit: B. Karas.

Step three: export surfacing Export or radial basis function (RBF) surfacing of a basic surface completes the digital post-processing allowable with the FastSCAN software. This final step continues to smooth the image surface, fills any voids in the data, creates a surface with highly uniform triangles, and produces a closed, watertight surface. The RBF results can be exported in a variety of formats for use with modeling software, such as Rhinoceros® and Flamingo.

Step two: basic surfacing The next step is basic surface processing, which merges the individual sweeps to give a smooth yet detailed surface (Fig. 9). This step requires the user to set numerical parameters and entails time to experiment with 107

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS insufficiently opaque to fully block Mongolia’s extreme summer sunlight. Wind gusts also frequently deanchored the canvas from its pegs allowing sunlight to penetrate the shelter. To compensate, lightweight black fabric was used for localized shading inside the canvas shelter.

The resulting 3D graphic models can then undergo manipulation for use in virtual exhibit and analysis applications. These data files can also be transferred to a special CNC milling machine, which uses it to guide the cutting tools in making reproductions. Field procedures The FastSCAN 3D laser’s portability and compactness make it highly desirable as a tool for archaeologists and conservators working on site. Overall, there are only two drawbacks to using this laser as a field tool: it is highly light sensitive, and it cannot be used in the vicinity of metal objects. Both of these characteristics introduced some logistical challenges for scanning the deer stones.

Setting up the scanning equipment and the generator was straightforward, very fast and required only one person. Previous experiments had shown that in the right environmental conditions, scanning could be a oneperson job. In this pilot study, however, three people were required: one person to operate the wand; one to view the scanning process on the computer screen and verbally guide the wand operator over problem or missed areas; and a third to locally shade areas of the stone that were receiving too much light. To ensure the best results, the reference receiver was used to establish the fixed datum point on the deer stone (Fig. 11). It was temporarily attached to the stone on a narrow face at mid-height, using heavy tape. Each side of the stone was scanned sequentially, using a slow sweeping motion from top to bottom or side to side as needed, with care taken to avoid scanning the reference receiver and the taped area. To complete the deer stone scan, a program option was activated at the end of the procedure that allowed the reference receiver to be removed and the area that it occupied to be scanned.

Figure 10: Standard shade shelter construction and scanning set-up, shown for Ulaan Tolgoi deer stone #5. Photo: H. Beaubien.

Creating the best lighting conditions for scanning proved to be the most time consuming aspect of the project by far. A successful scan is determined by the degree of laser contrast against the surface being scanned. In the same way that shiny or translucent objects make poor scanning subjects, sunlight interference diffuses and weakens the laser-line contrast, resulting in either a complete loss of the laser profile or an inconsistent profile with many voids in the collected data. Previous field experiments had shown that the combination of an overcast sky and a dark backdrop provided the best scanning conditions (cold temperatures precluded the use of the scanner at night). However, most of the DSP scanning took place under sunny conditions, which necessitated the use of shade shelters large enough to accommodate the equipment and provide reasonable access to all deer stone surfaces. Unfortunately, metal supports could not be used, as metal deforms the scanner’s magnetic field, potentially distorting the scanned image. Trial tests in Mongolia resulted in shade shelter construction specific to the conditions: mediumweight canvas draped over wooden poles, including 5meter lengths borrowed from neighboring animal corrals (Fig. 10). Eliminating light inside the shade shelter remained a challenge, as the canvas proved to be

Figure 11: Reference receiver attachment, shown on Ulaan Tolgoi deer stone #1. Photo: H. Beaubien.

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BASILIKI VICKY KARAS, HARRIET F. BEAUBIEN, AND WILLIAM W. FITZHUGH: DOCUMENTING MONGOLIA’S DEER STONES Trials Field testing the laser in Mongolia was a process that evolved through much trial and error beginning in late June. The first test to combat the light and metal sensitivities of the laser scanner employed a portable self-contained shower enclosure, of the type used for camping. The enclosure was set up over a deer stone (DS #1) as part of a brief equipment check, during a stop at the site of Ushkiin Uver (Fig. 12). Even though the shelter was open to the sky, the overcast conditions allowed preliminary scanning to proceed without significant light interference. Unfortunately, the shelter could not stand up to the conditions at Tsatstain Khoshun, a site previously test-excavated by the DSP, where the second trial took place. Constant wind, and eventually rain, ended the scanning trial of deer stone #1 at this site. Although neither site yielded complete results, these preliminary tests confirmed the promising capabilities and exposed the limitations of the laser scanner in the field.

Figure 13: Intermediate shade shelter construction and scanning set-up, shown for deer stone #1 at Efd Valley site. Credit: C. Thome.

With these encouraging results and the improved shelter design, the Erkhel Lake region became the major focus of the laser scanning program. This region has presented a particularly fruitful area for the DSP’s archaeological investigations since 2001 (Fitzhugh 2004; Fitzhugh 2003). Deer stone sites situated around the lake include Ulaan Tolgoi, containing a cluster of five granite deer stones (Fig. 14); and two smaller sites referred to as Erkhel East and Erkhel North, each with two deer stones.

Figure 12: Initial shade shelter construction and scanning setup, using portable shower enclosure. Photo: B. Karas.

Deer stone #1 at the Efd Valley site was the only stone out of the twelve trials that was not a standing stone. Its prone position provided the only opportunity to scan all surfaces of a deer stone. The exposed surfaces appeared at first glance to be devoid of any decorative elements, and it was hoped that the scanned image would reveal what the eye could not. An improvised shelter, replacing the now-retired portable shower enclosure, was made from plastic tarps, short wooden poles and duct tape (Fig. 13). The first attempt at scanning this stone ended prematurely, as several metal tripods in close proximity to the scanning equipment disrupted the system’s magnetic field. Once these were moved, the second attempt was successful in capturing good quality raw data, which revealed a carved chevron pattern on one of the stone’s lateral faces. This stone was also successfully turned during the scanning process so that the final surface could be scanned, a procedure requiring that the reference receiver’s position be undisturbed. The turning did not interrupt the scanning process or affect the data capture.

Figure 14: Ulaan Tolgoi site showing deer stones #1 through #5. Foreground shows deer stone #2 measuring 3.8m. Credit: C. Thome.

Of these sites, Ulaan Tolgoi was selected as the primary scanning test site for several reasons. The deer stones exhibited a representative range of conditions, including weathering, erosion, lichen growth and staining, and their isolated location presented working conditions 109

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS average of 2 to 3 hours to set up the shade shelter and scan one deer stone. Two deer stones could be scanned in a day’s time, weather permitting. The raw data files collected for each scanned stone fell within the standard size range, from 23.1 MB to 95.6 MB, and were easily stored on the laptop computer. Given the time commitment required for working with the raw data files, the most practical level of post-processing in the field was limited to temporary conversion of the raw data directly into a basic surface using default settings. The quality of the basic surface was sufficient to allow the team to assess the scans for significant errors and voids.

typical of the majority of deer stone sites in Mongolia. In addition, this remote region’s increasing popularity for adventure tourism has heightened the risks of vandalism and looting. Finally, the site provided a manageable number of deer stones, several of which are beautifully carved. Their documentation would complement the archaeological information and comprehensive mapping data accumulated by the DSP, including data from the current year. There is otherwise no published record of prior research at this site, although a Mongolian and Russian archaeological team is known to have raised and cemented two fallen deer stones (#1 and #2) into an upright position in 1992–1993 (Fitzhugh 2004; Sanjmyatov 2005)

All post-processing steps for the ten complete data files were carried out at MCI. Once processed as an export surface, scan data for each of the deer stones was converted to a Rhino model file (3DM); this allowed data to be manipulated for animation and milling. OEC is expected to play a key role in the milling and physical modeling stages. A Haas TM-1 CNC milling machine used at OEC is able to machine high-quality, detailed positives (reproductions) or negatives (molds) in virtually any material with the exception of some ceramics, titanium, magnesium or high-quality stainless steel.

Ulaan Tolgoi also presented a significant logistical challenge for scanning. Deer stone #2 is the tallest one known to date, at 3.8 meters (see Fig. 14), which gave us another opportunity to test the laser’s capabilities. This stone required a ladder to scan the upper portion and perseverance in creating adequate shade with the supplies at hand. Because of the range limitations of the scanner, the upper and lower halves of the stone had to be scanned as separate phases; the two data files will need to be digitally stitched together at a later date. With the completion of the Ulaan Tolgoi deer stones, the Erkhel East and Erkhel North deer stones were scanned with the remaining time available on site. Test excavations had just been completed at the latter site, which included the exposure and vertical positioning of one of the deer stones, formerly prone, prior to our arrival. The four deer stones, two at each site, were the final trials carried out during this field season.

Archaeological conservation applications The aim of this project was to test the utility of 3D laser scanning as a field tool for the archaeological conservator and to assess its potential role in the preservation of Mongolia’s deer stones. The results of trial scans from twelve deer stones clearly demonstrate the technology’s enormous potential in both respects. The scanning technique’s portability offers a particular advantage for documenting monuments in remote areas that would otherwise be neglected. Accurate, high resolution digital records of dimensional and topographic information were produced in an archaeological setting and in challenging environmental conditions. The ability of this laser system to withstand the rigors of rough transportation throughout northern Mongolia added to its value and reliability as a field tool. The digital records themselves provide detailed information that is useful to art historians and other researchers interested in iconographic and material studies. In the case of the deer stones, this includes accurate representations of the carved images, their distribution around the stone, carving technique details and other aspects of production. When applied to any number of cultural materials, the scan data files can generate profiles, cross sections and even 2D drawings. Virtual analyses using metrological applications provide measurements of diagnostic features and other physical characteristics such as tool marks, wear patterns and areas of loss.

Figure 15: Ulaan Tolgoi deer stone #5 photographed in situ on the left and a screen shot of the 3D scanned image (basic surface file) on the right. Credit: B. Karas.

Results Overall, the twelve scanning trials provided valuable information about the practical application of laser scanning in an archaeological field setting. From these trials ten resulted in complete data files, even with the challenges posed by the laser’s operational limitations (Fig. 15). At the time of the last scanning trials at the Erkhel Lake sites, the three-person team required an

From a conservation perspective, the digital documents constitute a baseline record of each object’s current state; this is of particular importance for monuments that are progressively compromised, whether by environmental or human causes. Baseline records are fundamental for 110

BASILIKI VICKY KARAS, HARRIET F. BEAUBIEN, AND WILLIAM W. FITZHUGH: DOCUMENTING MONGOLIA’S DEER STONES Chalmers, A., T. Saigol, and C. Green. 2001. An automated laser scan survey of the Upper Palaeolithic rock shelter of Cap Blanc. Journal of Archaeological Science 28: 283-289.

monitoring changes, and along with documentation of maintenance and responsive treatment actions, provide substantiating information toward the development of strategic plans for conservation and preservation. As with any form of documentation, they also are the foundation of an information archive. One invaluable application of such an archive is as a record of cultural heritage for use in bilateral agreements and other international efforts to control the illegal trafficking of stolen art. In the case of loss, they become the only source of information.

Fitzhugh, W. 2003. Archaeological site reports. In Mongolia’s Arctic Connections: The Hovsgol Deer Stone Project, 2001–2002 Field Report, ed. W.W. Fitzhugh, 37-51. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution. Fitzhugh, W. 2004. Project goals and 2003 fieldwork. In The Hovsgol Deer Stone Project, 2003 Field Report, ed. W.W. Fitzhugh, 1-24. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution.

A unique benefit of this technology is the ability to manufacture replicas at any scale from digital files using CNC milling machines. These can be distributed for research or museum use, with a ‘voucher’ copy serving as an accurate record of the original. In extreme cases replicas can act as in situ replacements for originals, whose high-risk condition requires them to be moved to an environment that better promotes long-term preservation. In addition, computer modeling of the scan data expands the potential for education and analysis by presenting an opportunity for virtual exhibit and study of cultural material to a global audience.

Fitzhugh, W. 2005. The Deer Stone Project: Exploring northern Mongolia and its Arctic connections. In The Deer Stone Project: Anthropological Studies in Mongolia 2002–2004, eds. W. Fitzhugh, J. Bayarsaikhan, and P. Marsh. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution. Frohlich, B., M. Gallon, and N. Bazarsad. 2004. The khirigsuur tombs. In The Hovsgol Deer Stone Project, 2003 Field Report, ed. W.W. Fitzhugh, 42-61. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution.

Acknowledgements We extend special thanks to the following people: Carolyn P. Thome (Smithsonian Office of Exhibits Central), our third scan team member; Tsog, Tserenyam and Adiyabold, for logistical assistance in Mongolia; Dan Ratta (Polhemus), for technical support with the FastSCAN™ equipment; and Brent Price (Applied Research Associates NZ Ltd.), for technical support with post-processing.

Frohlich, B., N. Bazarsad, and Baatartsogt. 2005. Burial mounds in Hovsgol Aimag, northern Mongolia: preliminary results from 2003 and 2004. In The Deer Stone Project: Anthropological Studies in Mongolia 2002–2004, eds. W. Fitzhugh, J. Bayarsaikhan, and P. Marsh. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution.

Bibliography Ahmon, J. 2004. The application of short-range 3D laser scanning for archaeological replica production: the Egyptian tomb of Seti I. The Photogrammetric Record 19 (106): 111-127.

Godin, G., F. Blais, L. Cournoyer, J.-A. Domey, J. Taylor, M. Rioux, and S. El-Hakim. 2003. Laser Range Imaging in Archaeology: Issue and Results, IEEE/CVPR Workshop on Applications of Computer Vision to Archaeology (ACVA’03) Madison, Wisconsin, July 17, 2003.

Baiarsaikhan, J. 2004. Notes on the meaning of deer stone iconography. In The Hovsgol Deer Stone Project, 2003 Field Report, ed. W.W. Fitzhugh, 35-41. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution.

Goskar, T., A. Carty, P. Cripps, C. Brayne, and D. Vickers. 2003. The Stonehenge lasershow. British Archaeology 73. http://www.britarch.ac .uk/ba/ba73/feat1.shtml.

Bayarsaikhan, J. 2005. Shamanistic elements in Mongolian deer stone art. In The Deer Stone Project: Anthropological Studies in Mongolia 2002–2004, eds. W. Fitzhugh, J. Bayarsaikhan, and P. Marsh. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution.

Jacobson, E. 1984. The stag with the bird-headed antler tines: a study in image transformation and meaning. Museum of Far Eastern Antiquities Bulletin 56: 113-180.

Beraldin, J.-A., M. Picard, S.F. El-Hakim, G. Godin, L. Borgeat, F. Blais, E. Paquet, M. Rioux, V. Valzano, and A. Bandiera. 2005. Virtual reconstruction of heritage sites: opportunities and challenges created by 3D technologies, The International Workshop on Recording, Modeling and Visualization of Cultural Heritage, May 22–27, 2005, Ascona, Switzerland.

Jacobson, E. 1993. The Deer Goddess of Ancient Siberia: A Study in the Ecology of Belief. Leiden and New York: E. J. Brill. Jacobson, E. 2002. Petroglyphs and the qualification of Bronze Art mortuary archaeology. Archaeology, Ethnology and Anthropology of Eurasia 3 (II): 32-47. 111

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Jacobson-Tepfer, E. 2001. Cultural riddles: stylized deer and deer stones of the Mongolian Altai. Bulletin of the Asia Institute, New Series/Vol. 15: 31-56.

Biographies Basiliki Vicky Karas is a conservator at the Smithsonian Museum Conservation Institute (MCI). She holds a BA (anthropology and classical studies), an MA (classical archaeology), and a master’s degree in art conservation. Vicky has worked as an archaeologist and conservation intern on projects in Jordan, Canada, Italy, Greece, Guatemala, and Mongolia. Her primary research at MCI involves the application of 3D laser scanning techniques in the non-contact documentation and preservation of cultural heritage.

Kubarev, V.D. 1979. Drevnye izvayaniya Altaya: Olennye Kamni. Novosibirsk. Reprinted in The Deer Goddess of Ancient Siberia: A Study in the Ecology of Belief by E. Jacobson. New York: E. J. Brill. Levoy, M., K. Pulli, S. Rusinkiewicz, D. Koller, L. Pereira, M. Ginzton, S. Anderson, J. Davis, J. Ginsberg, B. Curless, J. Shade, and D. Fulk. 2000. The Digital Michelangelo Project: 3D scanning of large statues. Proceedings of the 27th International Conference on Computer Graphics and Interactive Techniques, New Orleans, 23–28 July 2000, 131-144. New York: ACM Press.

Harriet F. (Rae) Beaubien is senior objects conservator at the Smithsonian Museum Conservation Institute. She heads a specialized program in archaeological conservation (established 1990), carrying out collaborative technical studies, on-site assistance, and education. Her primary fieldwork projects have been in Central America, the Mediterranean area, and South Asia. She holds a BA (art) from Beloit College, an MA (art history) from the University of Chicago, and an MA/certificate (objects) from New York University’s Conservation Center.

Mettenleiter, M., F. Härtl, I. Heinz, B. Neumann, A. Hildebrand, T. Abmayr, and C. Fröhlich. 2003. 3D laser scanning for engineering and architectural heritage conservation. In New Perspectives to Save the Cultural Heritage, The ICOMOS & ISPRS Committee for Documentation of Cultural Heritage, CIPA 2003, XIXth International Symposium, Antalya, Turkey (30 September – 04 October 2003): 485-489.

William W. Fitzhugh is Director of the Arctic Studies Center and Arctic Curator in the Department of Anthropology at the Smithsonian’s National Museum of Natural History. His research includes archaeological and cultural studies of circumpolar peoples, with fieldwork in Canada, Alaska, Scandinavia, Russia, and recently, Mongolia. There, his work on Bronze Age monuments has led to multidisciplinary investigations in a relatively unknown region, where arctic and steppe traditions may have blended, influencing North Pacific peoples and cultures long before the establishment of the Silk Road.

Natsagbadam, M. 2002. Mongolian Ancient Monuments [CD only]. Ulan-Bator: Cultural Heritage Center. Polhemus. 2001. FastSCAN Cobra & Scorpion. Product Information Brochure. Colchester, Vermont. Sanjmyatov, T. 1993. Early History and Culture of Archangai [published in Russian]. Ulaanbaatar. Sanjmyatov, T. 2005. Personal communication, June 2005. Taylor, J., J.-A. Beraldin, G. Godin, L. Cournoyer, R. Baribeau, F. Blais, M. Rioux, and J. Domey. 2003. NRC 3D technology for museum and heritage applications. The Journal of Visualization and Computer Animation 14 (3): 121-138.

Addresses *Basiliki Vicky Karas Smithsonian Museum Conservation Institute Museum Support Center 4210 Silver Hill Road Suitland, MD 20746-2863 USA

Tsultem, N. 1989. Mongolian Sculpture. Ulan-Bator: State Publishing House.

Harriet F. Beaubien Address same as for Karas

Volkov, V.V. 2002. Stone Stelaes from Mongolia (“deer stones”) [published in Russian, Olennye Kamni Mongolii]. Moscow: Scientific World [reprint of 1981 publication by Mongolian Academy of Sciences, Ulaanbaatar].

William Fitzhugh Arctic Studies Center Department of Anthropology National Museum of Natural History Smithsonian Institution Washington, DC USA

Wallace, E., and B. Frohlich. 2005. Bronze Age burial mounds in northern Mongolia: Use of GIS in identifying spatial and temporal variation. In The Deer Stone Project: Anthropological Studies in Mongolia 2002– 2004, eds. W. Fitzhugh, J. Bayarsaikhan, and P. Marsh. Washington, DC: Arctic Studies Center, National Museum of Natural History, Smithsonian Institution.

* Author to whom correspondence should be addressed

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DOCUMENTATION AND LASER SCANNING OF THE CAVATES (CLIFF DWELLINGS) IN BANDELIER NATIONAL MONUMENT, NEW MEXICO Jim Holmlund, Angelyn Bass Rivera, and Lauren Meyer Abstract Deep within the mesas and canyons of the Pajarito Plateau in northern New Mexico are thousands of earthen-plastered dwellings carved into the rhyolite tuff cliffs. These cliff dwellings, known as cavates, were once part of larger stone masonry villages that were occupied from the 12th to the 16th centuries. The cavates are set within a landscape sculpted by erosion. Despite the constant and often extreme physical alteration of the soft tuff cliffs, some of the cavates are well preserved and retain their form, features, and archaeological significance. A multi-phase project is under way at Bandelier National Monument to locate, document, prioritize, and conserve the cavates as both constructed and natural heritage. This paper briefly describes the cavates and the conservation project, and then focuses on laser scanning as a method of detailed documentation. The laser scan data and 3D modeling products not only provide a highly accurate record of the spatial dimensions and features of the cavates, but can also be used as tools for research and public education. The advantages and disadvantages of using this technology in this context are discussed.

Figure 1: Frijoles Canyon in northern New Mexico is the ancestral home of Tewa- and Keres-speaking Pueblos of the northern Rio Grande area. Photo: Shawn McLane.

Although various archaeologists have undertaken studies of the cavates (Hewett 1909; Hewett 1938; Chapman 1917; Chapman 1938; Lister 1940; Hendron 1940; Hendron 1943; Turney 1948; Toll 1995; Powers and Orcutt 1999; Kohler 2004), we still know very little about them. There are no written records that document their use, and Native American oral traditions that describe their function are not known. Based on the type and distribution of built-in features within the cavates, as well as analysis of scattered artifacts, we believe the cavates were used for habitation, storage, and special purposes or ceremonies.

Description of the cavates On the eastern flank of the Jemez Mountains of northern New Mexico is the Pajarito Plateau, an area of high mesas and sheer-walled canyons formed from the erosion of ancient lava flows and deep volcanic ash deposits. In the southern portion of the plateau is Bandelier National Monument (part of the National Park Service, NPS), where there are thousands of ancestral Puebloan dwellings built of stone masonry and carved into the rhyolite tuff cliffs. Native Americans and others have used the plateau for thousands of years. Some of the better known archaeological sites are in Frijoles Canyon, which was intensely populated from the 1100s into the mid-1500s (Fig. 1). Among these significant sites are cliff dwellings called cavates. The term cavate is derived from the words ‘cave’ and ‘excavate’ and appears as early as 1896 (Mindeleff 1896).

Cavate construction and use The cavates were carved directly into the soft, rhyolitic tuff cliffs formed from two separate eruptions and ash flows of the Valles volcano approximately 1.6 and 1.2 million years ago. Most of the cavates were excavated into a weakly cemented zone where the two ash flows meet. Cavates tend to be clustered on south or southeast facing cliffs that receive direct sunlight in the cold plateau winters. With this southern exposure, ambient temperature and relative humidity levels fluctuate radically, both annually and diurnally. These environmental fluctuations accelerate erosion and weathering of the tuff, which make the cliffs bases ideal for building and occupation, but problematic for preservation because of their progressive deterioration.

The cavates that honeycomb the sheer tuff cliffs of the region are architecturally unique. Not only are they carved directly into the rock, but they also contain numerous features related to processing food and weaving fabric, and earthen plasters that are not often preserved in standing architecture from that time period. It is in the cavates that the domestic details of the prehistoric Puebloan peoples’ lives are still visible. Modern pueblo people visit the cavates and acknowledge them as an integral part of an ancient landscape to which they are strongly and deeply connected. The Tewa word for the cavates is t’ová tewha, which roughly translates to “old or crumbling villages against the wall.”

From the deep striations and gouges in most cavate ceilings we can tell that their builders pecked, carved, and chiseled the soft tuff with tools such as digging sticks or stones. Today the cavates appear as groups of partial and complete chambers, but when they were in use, most were the back rooms of larger cliff-side villages constructed of masonry. Most of the masonry structures have partially or fully collapsed.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS The project also provides education and training in archaeological site conservation to graduate and Pueblo students, conservation interns, archaeologists, and park staff.

Figure 2: The interior walls of most cavates have a dado, or band of plaster, approximately 1 meter high, and some have traces of mural paintings or incised embellishments in the plaster and sooted tuff. Photo: NPS.

After carving the cavate, the builders often sooted the interior. The soot has the dual function of hardening and coating the grainy tuff surface to prevent it from disintegrating, and providing a homogenous interior color and texture. The exceptional preservation of some cavates is due in part to this sooty, protective layer. Following sooting, the floors and parts of the cavate walls were often finished with earthen plaster. Cavate floors usually have many layers of thick earth plaster that forms a hard, smooth surface on which to sit, sleep, and work at mealing bins, hearths, and looms. Deeply embedded in both the plaster and tuff portions of the floors are the remains of adobe and ash paste plugs, as well as wood loops that would have held the lower bar of a vertical loom. There is an abundance of weaving features in the cavates, which may point to a textile specialization in this area. Neither the loom anchors nor mealing bins (for grinding corn and other grains) are found in the standing masonry pueblos in Bandelier National Monument, and both are relatively rare features in all the early architecture on the Pajarito Plateau. The interior walls of most cavates have a dado, or band of plaster, approximately 1 meter high, ending at eye level if one is sitting on the floor (Fig. 2). Dados vary in color from red to white to yellow, and can have up to 30 layers. Some cavates also have traces of mural paintings, but after centuries of aging and weathering, only a few are discernible (Bass Rivera 2005). Conservation of what remains of these ephemeral earthen finishes is one of the park’s highest priorities.

Figure 3: Documenting the cavates in Frijoles Canyon. Photo: Angelyn Bass Rivera.

Phase I of the project involved archival research, preliminary analysis of the earthen plasters and the Bandelier Tuff, and stone performance testing (Provencher 1998; Provencher 1999; Matero et al. 1998; Matero 2004). In Phase II, the architecture and the physical condition of over 1,000 cavates in Frijoles Canyon were systematically recorded and assessed (Fig. 3); a database and geographic information system (GIS) were developed to integrate spatial data with detailed condition assessment information and images (Middlebrook 2003); a prioritized treatment schedule that sorts the cavates into categories of high, medium, or low priority for treatment was prepared; immediate and long-term treatments and monitoring activities for each cavate were proposed as part of a preliminary treatment plan; and pilot conservation treatments were designed and field-tested (Forrest 2001; Bass Rivera et al. 2002; Bass Rivera et al. 2003; Bass Rivera et al. 2004; Meyer 2002; Meyer 2003). Priorities for treatment are based on two principal factors: their archaeological significance1

Conservation project Project history In 1998, a three-phase project began to study and conserve the cavates. Funded by the National Park Service, the Getty Foundation, the Tauck Foundation through the National Parks Foundation, and the Friends of Bandelier, the principal objectives of the project are twofold: 1. To develop appropriate methods to document, conserve and maintain the cavates as both constructed and natural heritage. 2. To develop a formal conservation plan to preserve their many and varied values.

1 In this context, archaeological significance differs from cultural significance: archaeological significance is determined by the presence or absence of tangible architectural and archaeological features in the cavates; cultural significance involves both the tangible and intangible values of cavates and is determined by all the stakeholders, with an emphasis placed on heritage values assigned by affiliated Pueblos (Santo Domingo, Santa Clara, San Felipe, Zuni, Cochiti, and San Ildefonso). A separate study of the cultural significance of the cavates

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JIM HOLMLUND, ANGELYN BASS RIVERA, AND LAUREN MEYER: DOCUMENTATION AND LASER SCANNING and physical condition, and to a lesser extent, visitor access and use. In Frijoles Canyon, about 84 of the cavates, or 8%, have a high priority for treatment.

3D laser scanning 3D laser scanners—or LiDAR (Light Detection And Ranging)—are relatively new mapping instruments that allow the collection of thousands or even millions of points to define the shape of an object or feature in three dimensions. Laser scanners use both visible and nonvisible light frequencies, which define and constrain various measurement capabilities such as accuracy, resolution, and measuring distance. Three basic methods are used to derive point cloud data using a 3D laser scanner: time-of-flight, triangulation, and phase-shift. Each method has significantly different measuring properties. Generally, time-of-flight scanners provide long-distance scanning with lower accuracy and slower acquisition rates than the other two types of scanners. These are the scanners most used in outdoor scanning projects because they tend to use stronger, visible frequency lasers. Triangulation and phase-shift scanners are typically used for sub 25-meter data collection, and many will only collect data out to several meters from the scanner. However, these scanners typically collect data at rates of 100 or more times the rate of time-offlight scanners and are 2 to 100 times more accurate. Because of their sensitivity to certain light frequencies, many of these instruments can only be used in environments with artificial light or at night.

Phase III is currently under way and focuses on the highpriority cavates. It includes detailed documentation (35mm, medium-format, digital photography, and laser scanning; feature descriptions and mapping; and graphic condition recording), environmental monitoring, materials analysis, continued treatment testing, cultural significance assessments, and preparation of a conservation plan. Condition assessment results and preliminary treatment testing One of the challenges of conserving the cavates is how to preserve their physical integrity despite constant landscape-level change and erosion of the cliffs. The cavates are slowly deteriorating from both environmental and human impacts. Preliminary geomorphic assessment of cavates and cliff bases in Frijoles Canyon revealed that deterioration of the tuff occurs primarily through small-scale spalling and granular erosion, and to a lesser extent from large-scale rock falls. The primary processes contributing to gradual erosion of cavates are the discharge of water from the vadose zone at the cliff base, and capillary rise of moisture into the tuff. This is combined with deterioration processes such as soluble salt dissolution and crystallization, wet/dry and freeze/thaw cycling, and wind-blown particle abrasion. These findings correlate with the condition assessment data that reveals that cavates on the ground level in contact with the talus slope were generally more eroded and in poorer condition than those on the second and third stories, which were in significantly better condition, many of them well preserved.

The different measuring characteristics of each of the scanners define the type of objects and features that can reasonably be scanned. For many of the triangulation scanners, for instance, small objects such as artifacts, rock art elements, and intricate portions of larger objects can be scanned at very high resolutions (down to 0.05 mm), but because of the small scan area of each individual scan, larger objects or features require an unreasonable number of scans, and produce unmanageably large file sizes. Triangulation scanners also acquire spatially accurate color; however, color rendition is a function of the quality of the lighting used. Triangulation scanners can be used for artifact and rock art documentation, virtual museum projects, highresolution monitoring and 3D replication projects, to name a few. Terrestrial time-of-flight and phase-shift scanners, on the other hand, are used for the documentation and characterization of larger features such as historic buildings, mines, caves, cliff dwellings, standing prehistoric architecture, and ground surfaces, because of their long range and large acquisition windows. These scanners can be used to characterize complex natural terrain (caves, cliffs, boulder piles) or cultural features (building exteriors/interiors, mines) not typically mapped by standard surveying and mapping methods (terrestrial or aerial photogrammetry, for instance). However, the higher error (3 mm to 5 cm), lower average resolution, and larger beam spot diameters found in time-of-flight scanners do not allow them to be used for documentation of small or intricate objects and generally disqualifies them from monitoring studies. The ability to record the intensity of the reflected beam means that time-of-flight scanners can be used to identify and map surface reflectivity differences such as are found between patinated or weathered rock surfaces and

In 2002, we began field-testing both preventive and remedial conservation treatments for the high-priority cavates including masonry stabilization, controlling surface water runoff down the cliff face with silicone drip lines, tuff consolidation and infilling, and graffiti mitigation. We are continuing to evaluate cavate deterioration through comparative photography and are carrying out environmental monitoring of the interior and exterior of select cavates. In addition, we are testing various methods of detailed documentation for use as an archival record, for study and monitoring, and for exhibition off site. A range of methods has been tested and used to record the cavates within their landscape, including 35mm and medium-format stereo photography, measured drawings, total station mapping, and recently, laser scanning, described below. Each method has its advantages and disadvantages for recording different types of features at varying scales, resolution, and levels of accuracy.

is planned, and when completed, will likely change our management priorities, as well as our approaches to treatment.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS petroglyphs or pictographs, or between stone, wood, plaster, brick, metal, paper, or other construction material and painted, incised, pecked, carved, or treated surfaces.

Use of laser scanners at Bandelier National Monument In 2003 and 2005, Western Mapping Company undertook field trials to compare the effectiveness of various laser scanning methods and equipment, as well as their suitability on site, to record different architectural features at different scales and resolutions. Two areas with cavates were selected for scanning: Group M and Long House. Group M has extremely weathered cliff faces with deeply carved interconnected cavates (Fig. 4). Long House has very shallow cavates and numerous petroglyphs and plastered cliff faces (back walls of collapsed masonry rooms) (Fig. 5). In addition to using laser scanning as a way to obtain a complete and accurate record of both the anthropogenic and natural features, another objective was to find a way to model and monitor weathering and deterioration of the irregular surfaces of the cliffs. With the realization that the scan data acquired for high-resolution archival documentation may also be used for education and interpretive products, as well as models for monitoring, the use of scanners at Bandelier National Monument seemed a viable approach to documentation.

Ultimately, the decision to use laser scanners comes down to just a few considerations: (1) mapping or documentation accuracy, (2) mapping or documentation resolution, (3) potential products, and (4) cost. Data processing and products The three-dimensional data, as a series of registered point “clouds” collected from different positions around the target object, are registered together using specially designed software. This software uses algorithms which compare morphological characteristics of overlapping portions of scans to “register” or fit them together. The registration process—both in the field and in the office— can also involve the use of various types of surveying instruments including GPS, total station survey instruments, and differential leveling equipment. These instruments are used to position the 3D point cloud data in local or geodetic coordinate systems to establish an accurate vertical and horizontal reference orientation, as well as a position (coordinates) relative to other mapped objects.

Group M At Group M, the area scanned is a complex of deep, semi-enclosed, earthen-plastered cavates at the base of a cliff that are connected by narrow, semi-circular passageways. There are abundant large-sized architectural and archaeological features on the interior and exterior, including remnants of masonry walls, floor boxes, wall niches, adobe floor ridges, and empty sockets where there were once wood elements. Western Mapping Company personnel used a single scanner, the LeicaGeosystems HDS2500, to map and document the cavates and their associated masonry walls (Fig. 6). This instrument has an accuracy of about 3–4 mm. The area, including the cliff face, was scanned from distances of 10 to 25 meters. About 25 million points from 90 scans were collected in total. The data were not georeferenced, but all surveying used to register the scans together was referenced to datums established at the site for a future geo-referencing project. Digital color photography (5MP) was taken of the project area for use in colorizing the model.

After the data have been acquired and registered, the point clouds must be cleaned of unwanted imagery (plants, bugs, snowflakes, people, equipment, bad data, etc.). At this stage, some 3D vector CAD mapping and raster intensity studies can be completed directly from the registered point clouds. The point clouds are then converted to TIN (Triangular Irregular Network) models. Depending on which scanner is used, color may also be added at this point in the process. After processing the point clouds through to the model stage, the data are finally in a form that can be used interactively for metric analysis, 3D replication, or GIS applications, or further processed for visualizations and animations.

This scanner was generally well-suited for this type of mapping and documentation, having adequate range, accuracy, and speed. In addition to high-resolution, three-dimensional characterization of the cultural features, the scanner was used to map large, inaccessible areas of the cliff face above the architecture. The resultant scanning products can be used to identify geological and erosional vulnerabilities (e.g., fractured bedrock, joints, water flow pathways). There were, however, several limiting factors that became apparent when mapping the cavates with the HDS2500. The scanner is about the size of a small microwave oven, and it did not always fit into the small plastered niches or through some of the small doorways or openings. Furthermore, the scanner has a minimum range of 1 meter, making some scans in confined areas logistically

Figure 4: Group M, Frijoles Canyon, a three-story cavate pueblo consisting of earthen-plastered and interconnected cavates. Photo: Lauren Meyer.

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JIM HOLMLUND, ANGELYN BASS RIVERA, AND LAUREN MEYER: DOCUMENTATION AND LASER SCANNING preliminary animation. From the model we also derived profiles and contour lines, as well as planimetric CAD data to create various digital and hardcopy maps and graphic products for use by researchers and park staff (Fig. 8).

difficult or impossible. If high resolution is critical for characterizing small (< 2 cm diameter) floor features, fine incisions, or inscriptions, the HDS2500 scanner may not be adequate for the job. Where this is an issue, these features can be scanned with a higher-resolution and higher-accuracy laser scanner, and then the scans can be integrated with those created by the HDS2500.

Figure 6: James Holmlund and Joe Nicoli of Western Mapping Company prepare to scan cliff face and cavates of Group M. Photo: Western Mapping Company.

Figure 5: Long House Pueblo. Photo: Lauren Meyer.

A key feature of the HDS2500 scanner is that it can scan accurately without leveling the instrument, which is essential for mapping the tight confines and irregular spaces of the cavates. This is also crucial when the scanner must be raised above eye level to scan the tops of taller features. The HDS2500 scanner has a maximum effective range of about 100–150 meters (depending on the type and color of material being scanned), with a recommended optimal range of 50 meters or less. It works both in daylight and at night in temperatures down to about 36°F.

Figure 7: Group M TIN model. The TIN model consists of 2.3 million triangles. Image: Western Mapping Company.

Long House Long House was selected for laser scanning because of the area’s high archaeological significance and because the cavates and archaeological features are vastly different from those in Group M, which provided a good contrast for testing purposes. The tuff is relatively well cemented, but the slope of the cliff is overhanging and rock surfaces are discolored from water runoff that flows in heavy rainstorms. There are few deeply carved cavates like in Group M; instead, there are plastered cliff faces that were the back walls of three-story masonry rooms built against the cliff. The masonry walls have largely collapsed, leaving only the plastered rock, masonry

It should be noted that heavily sooted cavate ceilings are problematic to document with laser scanning because they absorb laser energy, which may substantially reduce the quantity of data points obtained from these surfaces (and hence, reduce resolution of the resultant model). Increasing laser power can partially overcome this problem, but also increases error. Some scanners cannot overcome this problem and simply cannot collect data in highly sooted areas (or from very dark rock types). From the Group M scanning project, we produced a 3D TIN model (Fig. 7). We applied digital color to the model and created various visualizations and a 117

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS foundations at the cliff base, and horizontal rows of empty sockets that once held roof beams. In addition to the architectural features, there are also hundreds of lowrelief petroglyphs covering the cliff face. For the Long House project, Western Mapping Company used the 3D Guru and Minolta 910 laser scanners. These scanners were selected to provide higher resolution scanning of the shallow, subtle features. The 3D Guru collects much more information (>100 times the resolution) in approximately the same scanning time as the HDS2500, with higher accuracy and resolution, but with a maximum scanning distance of about 25 meters. The Minolta is a triangulation scanner which scans small areas (< 1 square meter) at very high resolution and accuracy (0.1 mm, or less) and a maximum scanning distance of about 1.5 meters. Both scanners work only in the dark and cannot operate in temperatures near or below freezing.

scans of Long House were significantly less than 180 degrees, most of the data was usable and of high quality. The Minolta scanner also performed well in the field. The Minolta was used to scan several petroglyph panels and plaster surfaces. In general, however, the Minolta scanner is not well suited for large outdoor projects due to the sheer number of scans that must be obtained (at night). The average area scanned was about 0.61 square meters with about half of this devoted to overlap with previous scans, similar to photogrammetric methods.3 Each plastered wall surface scanned for this project required 28 scans with 9 million points. No color information was collected with the Minolta scans, although false-color reflectance data is available. Because the maximum scanning range of the Minolta scanner is about 1.5 meters, logistical issues such as scanning difficult-to-reach features are a concern when selecting this and other scanners for a project.

At Long House, a 10-meter-long section with standing coursed rock masonry foundations and assorted architectural features and petroglyphs on the cliff face were scanned. The plastered cliff faces were scanned with both scanners to test their effectiveness in providing detailed characterization for both documentation and future monitoring. Similar to Group M, the Long House scan data was not geo-referenced, but was tied by survey instruments to datums established in and near the project area. Future geodetic surveys will geo-reference these datums so that the scan data and products can be incorporated into the park’s GIS.

Preliminary results indicate that data sets from both scanners worked well for their particular tasks. Although the 3D Guru scanner had issues requiring much additional effort in the reduction phase, the data available is accurate and of sufficiently high resolution to characterize all architectural features and petroglyphs, except the smallest (< 0.5 cm). The Minolta scan data sufficiently characterized the plastered wall—even layers of plaster—so that any further deterioration of the plaster (e.g., small voids, cracks, partial loss) will be evident. The petroglyphs were well characterized by both scanners; however, morphometric analyses such as topographic and residual models are generally poor because of the rough surface texture of the tuff and the shallow relief of most of the petroglyphs. Nonetheless, characterization of the petroglyphs, even from the ground surface about 8 to 15 meters away, is of sufficiently high resolution to allow identification of most elements, as well as mapping.

Reduction of the Long House scan data has not been completed, but we have preliminary results (Fig. 9). The equipment generally performed well in the field. The 3D Guru scanner (which is no longer manufactured in this model) was lightweight, versatile, and had a short minimum acquisition range (45 cm); however, some of the 3D Guru data was inconsistent. Once we were out of the field and the data was inspected, it was apparent that several types of error had been introduced into 7 of the 23 scans (about 50 million points) taken at Long House. Some scan data seemed to be randomly introduced into individual scans as oddly intersecting patches of points within an apparently accurate main scan. These were relatively minor and easily removed, for the most part, although annoying and potentially problematic. Another, more serious data issue was the inability of a 360-degree horizontal scan to close accurately on itself.2 Data from scans significantly less than 180 degrees did not appear to have this problem (or was beyond statistically valid identification) as we noted during an unrelated and unpublished test where we compared the 3D Guru scan data to scan data obtained with other scanners and survey data. Despite these problems, and because many of the

We are currently working on visualizations of the Long House site scan data which will include both morphometric and color treatments of the data from high-resolution digital photography.

2 It appeared that a small scale factor error introduced by a systematic scanner head movement may be involved; however, we have been unsuccessful in having the company (BitWyse) that now owns majority interest in Visi-Image (the company from which the 3D Guru scanner was originally leased) to rectify this problem with these data, although it can apparently be rectified (by BitWyse personnel only).

3 Registering large numbers of Minolta scans together is a critical task in the data reduction stage. Small amounts of error in each registration can accumulate to many times the error inherent in a single scan. This fact can reduce or eliminate its utility for monitoring. Western Mapping Company is currently developing proprietary methods to reduce this problem.

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Figure 8: Planimetric map of the scanned portion of Group M cavates. Image: Western Mapping Company.

Figure 9: TIN model of Long House. Clearly visible are deep cracks in the bedrock, rows of viga sockets, plastered rock walls, and cavates. Image: Western Mapping Company, 2005.

be used in documentation or GIS applications) may require concurrent use of additional 3D laser scanners, other surveying instruments, and cameras in support of the laser scanning objectives. The decision to choose laser scanning should always be viewed in the larger

Conclusions Laser scanners should be envisioned as another mapping tool among the cadre of potential mapping and documentation methods available. Laser scanner use in the field environment (particularly where the results may 119

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS continuity of the natural processes of decay and renewal for others.

context of project goals, specifically accuracy, resolution, products, and cost. It is most cost-effective when high accuracy and/or high resolution is necessary and a wide variety of potential products are envisioned (mapping, documentation, monitoring, engineering, visualization, animation, 3D replication). User costs may include data storage, high-end computers capable of handling large 3D digital model files, and software training costs. Other recording methods (e.g., terrestrial or aerial photogrammetry, photo-mapping, survey instrument mapping, and measured drawings) may be more efficient and cost-effective depending on the desired products and goals of the project.

Acknowledgements The Frijoles Canyon Cavate Pueblo Conservation Project has been ongoing for nearly six years. It has been, and continues to be a collaboration involving many people and institutions. Among our partners deserving special acknowledgement are the Western Mapping Company and Jim Holmlund, who conducted the scanning and processing of the Group M data largely as a donation to the park; the University of Pennsylvania’s Graduate Program in Historic Preservation, and Professor of Architecture and Program Chair Frank Matero, who began the first field school and field project at Tsankawi Mesa in 1998 and has generously contributed to the work and training in Frijoles Canyon; the Museum of New Mexico, and Chief Conservator Claire Munzenrider and Conservator Larry Humetewa, who have helped us develop and implement innovative graffiti mitigation treatments. Immense gratitude is also extended to the project’s financial supporters, the National Park Service’s Vanishing Treasures Program, the Getty Foundation, the Tauck Foundation through the National Park Foundation, and the Friends of Bandelier.

Although the more conventional documentation methods noted above may be used (solely or in combination) to record features or objects in situ, none have the combination of accuracy, resolution, and speed of laser scanners. At Bandelier National Monument, where a significant amount of the architecture is carved into vertical cliff faces at multiple levels, conventional mapping methods and products alone are less than satisfactory. Laser scanning, particularly the use of multiple types of laser scanners with a range of measurement characteristics, allows the creation of highly resolved 3D digital models that, when combined with photography, can provide complete and accurate baseline documentation, virtually impossible to achieve with other mapping techniques. When these same models are referenced to highly stable and accurately positioned datums, they can also be used to study and quantify the types and rates of architectural and rock deterioration. Because the 3D models created from laser scanning are completely metric, measurements, descriptions, and characterizations can be made directly from the digital model. A significant benefit is that both researchers and visitors can study aspects of the cavates from these models without climbing into the cavates. Such actions that reduce direct access to the cavates not only minimize damage that can occur from visitation and conventional documentation methods, but are also desirable for some Native American groups that may prefer limited access to these sites.

Bibliography Bass Rivera, A. 2005. Carved in the cliffs: the cavate pueblos of Bandelier National Monument. In The Peopling of Bandelier: New Insights from the Archaeology of the Pajarito Plateau, ed. R. Powers, 8793. Santa Fe: School of American Research Press. Bass Rivera, A., L. Meyer, M. Slater, R. Hartzler, K. Fiero, L. Humetewa, L. Kleifgen, S. Middlebrook, S. Tringham, and R. Winters. 2002. Interim Project Report, Frijoles Canyon Cavate Pueblo Conservation Project and Field School in Site Conservation and Heritage Management, Bandelier National Monument, New Mexico. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM. Bass Rivera, A., L. Meyer, K. Fiero, M. Slater, S. Middlebrook, R. Burch, R. Hartzler, L. Humetewa, R. Ingraffia Jr., D. Langer, F. Matero, D. Oliver, P. Trieb, and S. Tringham. 2003. Project Report, Frijoles Canyon Cavate Pueblo Conservation Project and Field School in Site Conservation and Heritage Management, Bandelier National Monument, New Mexico. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

At this time, due to the sheer number of cavates, their location in remote canyons, and their imminent deterioration from erosion, the conservation efforts, including laser scanning for the most significant sites, will focus on the 84 high-priority cavates in Frijoles Canyon. At a minimum, all the cavates will be documented. In some cases, where preservation of the cavate or its features is not possible because of accelerated weathering or where no treatment is justified, they will be documented in higher detail. This prioritized management approach allows for the selection of appropriate treatments for each cavate based on our understanding of both its tangible and intangible values. Limited conservation and detailed documentation such as laser scanning attempt to strike a balance between allowing the continuity and preservation of the form and fabric of some cavates, while also allowing for the

Bass Rivera, A., L. Meyer, M. Slater, and L. Humetewa. 2004. Addendum to the Final Project Report, Frijoles Canyon Cavate Pueblo Conservation Project and Field School in Site Conservation and Heritage Management, Bandelier National Monument, New Mexico. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

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JIM HOLMLUND, ANGELYN BASS RIVERA, AND LAUREN MEYER: DOCUMENTATION AND LASER SCANNING Chapman, K. 1917. The Cave Pictographs of the Rito de los Frijoles. Santa Fe: School of American Archaeology.

Meyer, L. 2003. Project Report: Frijoles Canyon Cavate Conservation Project and Group M Case Study. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

Chapman, K. 1938. Pajarito pictography: the cave pictographs of the Rito de los Frijoles. In Pajarito Plateau and Its Ancient People, by E. Hewett, 139-148. Handbook of Archaeological History. Albuquerque: University of New Mexico.

Meyer, L., S. McLane, A. Bass Rivera, and M. Slater. 2005. Frijoles Canyon Cavate Pueblo Conservation Project: Graffiti Mitigation. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

Forrest, K. 2001. An Architectural Analysis and Earthen Finish Characterization of Cavate M-100, Frijoles Canyon, Bandelier National Monument, Los Alamos, NM. Unpublished master’s thesis, University of Pennsylvania, Philadelphia, PA.

Middlebrook, S. 2003. GIS as a Tool to Assess Heritage Risk: A Case Study in Frijoles Canyon, Bandelier National Monument. Unpublished master’s thesis, University of Pennsylvania, Philadelphia, PA.

Hendron, J. 1940. Prehistory of El Rito de los Frijoles, Bandelier National Monument. Southwestern Monuments Association Technical Series, Number One.

Mindeleff, C. 1896. Aboriginal remains in Verde Valley, Arizona. In Thirteenth Annual Report of the Bureau of American Ethnology, by J.W. Powell, 179-261. Washington, DC: U.S. Government Printing Office.

Hendron, J. 1943. Group M of the Cliff Dwellings, Rooms 1, 2, 3, 4 and 5, Caves 1, 2, 3, 4, Frijoles Canyon, Bandelier National Monument, New Mexico. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

Powers, R., and J. Orcutt, eds. 1999. The Bandelier Archaeological Survey: Volumes I and II. Intermountain Cultural Resources Management Professional Paper No. 57, National Park Service, Department of the Interior.

Hewett, E. 1909. The Excavations at el Rito de los Frijoles in 1909. Paper No. 10. Santa Fe: School of American Archaeology.

Provencher, S. 1998. Tsankawi Project Completion Report. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

Hewett, E. 1938. Pajarito Plateau and Its Ancient People. Handbook of Archaeological History. Albuquerque: University of New Mexico Press.

Provencher, S. 1999. Tsankawi Unit Cavate Conditions Assessment and Treatment Recommendations. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

Kohler, T., ed. 2004. Archeology of Bandelier National Monument: Village Formation on the Pajarito Plateau, New Mexico. Albuquerque: University of New Mexico Press.

Toll, H. 1995. An Analysis of Variability and Condition of Cavate Structures in Bandelier National Monument. Professional Paper no. 53. Santa Fe: Intermountain Cultural Resources Center.

Lister, R. 1940. Stabilization of Frijoles Cave Ruins, Bandelier National Monument. Unpublished report, copy on file at Bandelier National Monument, Los Alamos, NM.

Turney, J. 1948. An Analysis of the Material Taken from a Section of Group M of the Cliffs, Frijoles Canyon, Bandelier National Monument, New Mexico. Unpublished master’s thesis, Adams State College, Alamosa, CO, copy on file in Bandelier National Monument archives, Bandelier National Monument, Los Alamos, NM.

Matero, F. 2004. Exploring conservation strategies for ancestral puebloan sites: Tsankawi, Bandelier National Monument, New Mexico. Conservation and Management of Archaeological Sites 6(2): 67-84. Matero, F., S. Provencher, M. Kelleher, S. Kreilick, R. Preucel, and A. Freitag. 1998. Trail Preservation Study: Tsankawi Mesa, Bandelier National Monument, Los Alamos County, New Mexico, National Park Service. Unpublished report, copy on file at the Architectural Conservation Laboratory, Graduate Program in Historic Preservation, Graduate School of Fine Arts, University of Pennsylvania, Philadelphia, PA.

Biographies James P. Holmlund is president, sole owner, and principal surveyor at Western Mapping Company, a company specializing in geodetic surveying, mapping, and digital cartography. He began his career surveying, mapping, and conducting geophysical surveys for Arizona copper mines, mining engineering firms, and the US Defense Mapping Agency. His business is devoted to surveying and mapping in the geotechnical and environmental fields throughout the western states and Mexico for Federal, State, and local governmental agencies, universities, and private firms.

Meyer, L. 2002. The Preservation of a Resource: Archaeology, Stabilization and Interpretation in Frijoles Canyon, Bandelier National Monument. Unpublished master’s thesis, University of Pennsylvania, Philadelphia, PA. 121

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Angelyn Bass Rivera is a conservator with the National Park Service specializing in architectural finishes and management of archaeological sites. She received an MS in historic preservation from the University of Pennsylvania in 1998. She has been involved in conservation projects in the US, Africa, and Central America. She currently directs the Vanishing Treasures Program at Bandelier National Monument in New Mexico and has been leading the cavate conservation project since 2000. Lauren Meyer is an architectural conservator with Bandelier National Monument, National Park Service. She received an MS in historic preservation in 2002 and an Advanced Certificate in Architectural Conservation in 2003, both from the University of Pennsylvania. Lauren has worked on conservation projects in the US and Latin America. She is one of the principal investigators for the cavate conservation project and has been working on the project since 2002. Address *Angelyn Bass Rivera Archaeological Site Conservator Bandelier National Monument National Park Service 15 Entrance Road Los Alamos, NM 87505 USA *Author to whom correspondence should be addressed.

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COLLABORATIVE PROGRAMS FOR USS MONITOR CONSERVATION Marcie Renner and Steve Hand Abstract The Mariners’ Museum (TMM) is the federally designated repository of all artifacts and archives associated with the wreck of the USS Monitor. The USS Monitor conservation project, a joint effort between the Museum and the National Oceanic and Atmospheric Administration, is extremely complex and thus relies on collaborations with academic institutions, other conservation projects, professional groups, artists, and industries. Two of the primary corporate associations— Northrop Grumman and MAGLEV, Inc.—focus on analysis and documentation of Monitor objects. Northrop Grumman offers several types of nondestructive testing for TMM objects, including Xradiography and thermal wave imaging. MAGLEV, Inc., worked with TMM to employ cutting-edge threedimensional scanning technology to document many of the large artifacts recovered from the Monitor including the propeller, castings from the Dahlgren guns, the gun carriages, and the anchor. The resulting data will be used for conservation documentation and for analytical, interpretive, and marketing opportunities.

partnerships with academic institutions, other conservation projects, professional groups, artists, and industries to address conservation issues. Two of our primary corporate associations—with Northrop Grumman and MAGLEV, Inc.—focus on analysis and documentation of Monitor objects.

Figure 1: Architectural model of the USS Monitor Center addition to The Mariners' Museum.

Introduction The Civil War ironclad USS Monitor is one of the most significant vessels in American history. Designed by Swedish-American engineer John Ericsson, the Monitor engaged the CSS Virginia in the first battle between ironclad ships on March 9, 1862, in Hampton Roads, Virginia. In December of that year, the Monitor sank in a storm off Cape Hatteras, North Carolina. The wreck of the Monitor was located in August 1973, and in recognition of the vessel’s unique historical and archaeological significance, the Secretary of Commerce designated the wreck site as the nation’s first marine sanctuary on January 30, 1975. The Monitor National Marine Sanctuary (MNMS) is administered by the National Marine Sanctuary Program, National Ocean Service, National Oceanic and Atmospheric Administration (NOAA), an agency of the US Department of Commerce.

Northrop Grumman The Mariners' Museum has a long association with Northrop Grumman, formerly the Newport News Shipbuilding and Dry Dock Company. The Museum was founded by Archer Huntington, son of Collis Huntington who founded the shipyard. In the 75-year history of the Museum, the shipyard has provided extensive technical and logistical support to the Museum. For the Monitor project, Northrop Grumman continues this tradition. Northrop Grumman offers several types of nondestructive testing for TMM objects. One of the most interesting is the analytical work performed on the Monitor clock. Digital X-rays were taken to provide a guide for treatment of the clock mechanism and to possibly determine the time the clock stopped working. The X-ray images of the clock mechanism (Fig. 2) clearly show the inner workings and will be used for partial disassembly of the object.

In 1987, The Mariners’ Museum (TMM), located in Newport News, Virginia, was designated by NOAA as the official repository for all of the objects and archives associated with the USS Monitor. In this role, the Museum is charged with the conservation, exhibition, and curation of the Monitor’s artifacts. Toward these goals, TMM recently opened the USS Monitor Center, a 63,500 ft2 facility housing conservation laboratories, classrooms, and exhibition galleries dedicated to the USS Monitor (Fig. 1).

Because iron corrosion products remained on the face of the clock, conservators were hopeful that X-rays of the clock face would show the placement of the hands. The images, however, do not clearly reveal the hands. Analysts at the shipyard, therefore, decided to try thermal wave imaging (Fig. 3). From this analysis, the researchers were hoping to detect different diffusion rates possibly from leaching of the hand on the clock face. For the analysis, the shipyard used a Thermoscope II system from Thermal Wave Imaging; the infrared camera was a Merlin Indigo. Unfortunately, no definitive readings were discernible.

Due to the scope and complexity of the Monitor project, the Museum and NOAA are committed to forming

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS average resolution, or grid size, of three millimeters with an accuracy of ± 50 microns (± 0.002 inches). A point cloud is a file type where each point is defined as an ‘x, y, z’ coordinate value.

Figure 2: X-ray of the gear box from the Monitor's clock.

Figure 4: 3D model of the Monitor's propeller generated by coherent laser radar (CLR) and structured light scanning.

Approximately 15% of the surface was not in direct line with the scanner beam. These surfaces could have been scanned using optically flat mirrors since the CLR technology uses a focused laser system; however, the metrologists decided to use structured light scanning to both fill in the blanks and to provide greater resolution in areas of interest. Structured light scanning projects patterns of light onto the object; a digital camera then decodes the patterns to compute the surface topography. This technique generates a high resolution (point quantities in the millions) and provides greater detail for surface analysis. A downside of this technique, however, is that the structured light point cloud data is without scale. In order to dimension the point clouds, the data had to be scaled to the CLR points to create the highly accurate three-dimensional as-built model of the propeller.

Figure 3: Progressive thermal wave images from the face of the Monitor's clock.

MAGLEV, Inc. MAGLEV, Inc., is a Pennsylvania-based company with the mission of developing and deploying a magnetically levitated high-speed transportation system beginning in Pittsburgh. Through the initiative of Steve Hand, former senior metrologist for MAGLEV, the company worked with TMM to employ cutting-edge three-dimensional scanning technology to document many of the large artifacts recovered from the Monitor. Techniques such as time-of-flight, coherent laser radar, line scanning, and structured light three-dimensional digitizing are being employed to create accurate computer models and line drawings. The resulting data will be used for conservation documentation and for analytical, interpretive, and marketing opportunities.

The resulting data will be used in several ways. For one, it can be used to reverse engineer the propeller to determine its actual configuration when manufactured over 140 years ago. Reverse engineering is the practice of taking measurements and creating a 3D Parasolid model. In this case, the as-built model of the propeller was used to create a manufactured model by filling missing parts using the attributes of the existing propeller surfaces. A graduate student is currently using the models to evaluate the performance of the propeller, both in its current configuration with the three blades broken and in its original designed state.

Monitor propeller The first Monitor object to be scanned by MAGLEV was the screw propeller (Fig. 4). A combination of two scanning methods—coherent laser radar (CLR) and structured light—were used for recording the propeller. The CLR scanner directs a focused laser beam to a point on the piece to be measured and recaptures a portion of the reflected light. Because CLR requires line of sight, the scanner was placed in nine different positions during the 36 hours of scanning. Fifty-five point clouds, with a total of 1,667,984 individual points, were generated at an

Once an as-built 3D model is generated, it can be used for dimensional analysis, geometric dimensioning and tolerancing (GD&T), and color comparison to 3D 124

MARCIE RENNER AND STEVE HAND: COLLABORATIVE PROGRAMS FOR USS MONITOR CONSERVATION sculptor mold the surfaces as a record in the event of catastrophe. We also had positive casts made from the molds (Fig. 7).

Parasolid or other 3D as-built models. Images can be generated showing deviation in millimeters and demonstrating the capabilities of this technology to disseminate information for dimensional analysis. For conservation, this means that we have an incredibly accurate record of the current condition of the propeller. We can compare these data to those from future scans to detect even infinitesimal changes in the surface. In addition to condition and performance analysis, the 3D models are also useful for reproduction of exact features and conditions. The accuracies are greatly improved over manual coping and they can be used in many different manufacturing processes. For the museum, applications include scaling down models to create jewelry and other merchandise and casting fullscale replicas for use in exhibits or for hands-on educational opportunities. The solid free-form fabrication process—referred to as 3D printing—begins with a 3D model of an object. The point cloud data is converted electronically into commercially available CAD software and exported as a stereolithography file (.stl). The latter is electronically ‘sliced’ into layers that will correspond with layers of powder laid into a rapid casting or direct metal machine. The print heads accurately and selectively deposit micro droplets of binding solution on only the powder to be printed, bonding each layer until all cross-sections have been built. The 3D printing process produces fully functional metalwork pieces directly from CAD files in a matter of days rather than weeks or months. The result is a precision-made product that possesses unparalleled resolution.

Figure 5: Initials scratched on the surface of one blade of the Monitor’s propeller.

Propeller engravings During treatment of the propeller, conservators noticed initials scratched into the surface of one of the blades (Fig. 5). In October 1862, the Monitor was taken to the Washington Navy Yard for refitting; the initials were probably scratched at that time by a worker wanting to be associated with the famous vessel. To scan the initials, MAGLEV enlisted the help of Accurex, a company that specializes in 3D scanning, 3D coordinate measurement, and optical gauging systems. The initials were scanned using the structured white light 3D digitizing system described earlier. The results of the scans and subsequent processing are yielding important information on the engraving techniques and have confirmed the presence of a second set of initials (Fig. 6).

Figure 6: Laser scan detail of the engravings on the Monitor’s propeller.

Dahlgren gun engravings While the Monitor was being refitted at the Washington Navy Yard, the two XI-inch Dahlgren guns were engraved to commemorate the battle. Because the Monitor turned upside down during sinking, the guns were face down in the turret. When we began planning for lifting the guns out of the turret with expert riggers from Northrop Grumman, we had to consider that the engravings were right where the lifting straps would ideally be situated. Although the riggers knew to design the lift to avoid the engraved areas, we decided to have a

Figure 7: Laser scan of a gun carriage from the Monitor’s turret.

The resulting casts were scanned using structured white light 3D digitizing. One possible use of the data is for our education department to 3D print a scaled-down version of the cast in metal so that school children can make rubbings of the engravings. Once the guns are turned upright, we may scan the engravings and create a 3D print to evaluate the accuracy of the ‘traditional’ cast. 125

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Dahlgren gun carriages The gun carriages of the Dahlgren were recorded using the CLR and an articulating arm line scanning technology. This project was of special interest to MAGLEV, as well as to Northrop Grumman and NASA Langley, because the carriages needed to be kept wet during the scan. The metrologists found that as long as the water was not allowed to pool, the reflection off the surface did not adversely affect the scan. Because the carriages are composites of wood, iron, and copper alloy, they will be partially disassembled before conservation treatment. The scans will be used for reverse engineering of the carriages and will thus serve as the basis of the disassembly documentation.

Addresses *Marcie Renner The Mariners’ Museum 100 Museum Drive Newport News, VA 23606 USA

Monitor anchor The most recent scan of a Monitor object—the anchor— was performed by MAGLEV and Leica Corporation. This project involved the use of Leica’s new T-Scan Probe technology using a laser tracker and chargecoupled device (CCD) camera for scanner positioning. This particular system, primarily used by Leica for reverse engineering applications, is accurate to 100 microns (0.004 inches).

*Author to whom correspondence should be addressed.

Steve Hand Director of Fabrication-Nuclear Chicago Bridge & Iron Co. Blaymore II, Suite 201 1603 Carmody Court Sewickley, PA 15143 USA

Again, the main purpose of the scanning was to provide a detailed condition of the anchor. Because of the accuracy of the system, details such as depth of crevices, which are quite common on wrought iron, are accurately recorded. Conclusion Projects of the size and scope of the Monitor conservation effort require state-of-the-art techniques in various disciplines. Especially important is the capability to analyze and document the often complex artifacts. Laser scanning is a powerful tool with numerous applications for conservators, archaeologists, and other museum personnel. The advantages for documentation include incredible accuracy, speed of data collection, and most importantly, little or no handling of the object. Because the technology available for scanning is diverse and dynamic, the collaboration of a professional metrologist is essential. Biographies Marcie Renner serves as chief conservator at The Mariners’ Museum in Newport News, where she is responsible for overseeing treatment of over 200 tons of metal recovered from the wreck site of the USS Monitor as well as care of the museum’s core collection of objects and artwork. Steve Hand has been involved in the field of metrology for over 30 years with experience ranging from optical tooling and laser interferometry to the latest in threedimensional imaging and data processing. Steve currently consults for Survice Metrology and is a regular where high accuracy surface scanning and postprocessing data is required. 126

SAVING THE FERRYLAND CROSS: 3D SCANNING, REPLICATION, AND ANOXIC STORAGE Judith A. Logan, Robert L. Barclay, Paul Bloskie, Charlotte Newton, and Lyndsie Selwyn Abstract This paper describes the examination, treatment and replication of an archaeological composite metal cross (iron, brass and gold) recovered from the 17th-century English Colony of Avalon, located at Ferryland, Newfoundland. The cross was analyzed to determine details of structure, and to identify metals and corrosion. It was mechanically cleaned using air abrasion with aluminum oxide powder. Chloride ion removal was attempted by washing the object in a soxhlet extraction apparatus under an atmosphere of nitrogen. Subsequent active corrosion was dealt with first by consolidation followed by storage with dry silica gel. The cross continued to corrode, resulting in fresh breaks. There was an urgent need to document the condition of the cross in order to assess any future deterioration. The cross was 3D laserscanned and a reproduction was made using 3D printing technology. A container for dry, anoxic storage and display was constructed.

The extraneous material was extremely hard and dense. This outer concretion was analyzed using x-ray diffraction (Sirois 1986; Sirois 2000). The crystalline components identified were iron oxides (haematite, magnetite), iron oxyhydroxides (goethite, lepidocrocite), silicon dioxide (quartz), and aluminum oxide (corundum). Two crosssections of this extraneous material were also analyzed by energy dispersive x-ray spectrometry. The major elements were iron and silicon, suggesting that the hard outer material was most likely an iron silicate. Radiography revealed that the iron was cracked in many places, and the shaft of the cross was slightly bent. The finial was completely mineralized as were parts of the shaft and orbs. The central, square portion appeared very dense, with a lot of iron remaining. Removal of the disfiguring corrosion was essential to reveal the true shape and dimensions of the cross. The fragile nature of the cracked and mineralized iron, combined with the presence of traces of gold plating and brass, made conservation of the cross a challenge. The need for the cross to be on public display, where the prevailing environmental conditions include high relative humidity and chloride-containing aerosols, has been a continuing issue in its conservation.

Introduction In the fall of 1985, during a short season of excavation at the site of the 17th-century Colony of Avalon, located in Ferryland, Newfoundland, Canada, an unusual iron object was found in the remains of a forge dating from the mid17th-century (Tuck and Robbins 1986). The object was shaped like a cross, but details were completely obscured by a thick layer of corrosion which had incorporated the gravel and sand of the soil matrix (Fig. 1). Dr. James A. Tuck, director of the excavation, kept the object wet and brought it to the Canadian Conservation Institute (CCI).

Figure 1: The Ferryland Cross before cleaning 1985

This paper discusses the present condition of the cross, the historical context of the site, the archaeological context of the cross, and the various treatment options considered and used over the past 20 years. Also described is the recent approach taken for the cross. This has involved preventive conservation measures consisting of the following: a) Documenting the pieces using 3D laser scanning. This will stand as a permanent record of its condition, allowing future researchers and custodians to monitor change. b) Making reproductions using 3D printing technology. The reproductions were made from a composite 3D image created by merging the laser scanned images of each piece. A replica of the cross was used to create a custom-fitting support that holds the original pieces in their correct alignment without the use of adhesives. c) Creating a dry, anoxic storage/display environment that is economical to construct and easy to monitor and maintain. This was achieved using Escal, a commercially available gas barrier film, coupled with RP-A, an oxygen and water vapor scavenger.

Preliminary examination revealed that it was indeed a cross, with a complex structure involving at least three different metals: iron and two different yellow metals, one bright and the other dull. These were analyzed by energy dispersive x-ray spectrometry (Bokman and Laver 1985; Sirois 1995). The presence of iron was confirmed, the traces of bright yellow metal on the surface were identified as gold, and the dull yellow metal turned out to be brass.

Description of the cross Figure 2 shows a photograph of the cross taken in 1992 after removal of the extraneous material was complete and its overall shape revealed. For the purpose of description, we labeled the least damaged side of the cross as the “front,” and so refer to the proper right (PR) and proper left (PL) sides of the cross as it would have been held or mounted with the front facing forward.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS rectangular center portion, and a piece of the PL tang has broken off. It can now be seen that the shaft changes from being circular in cross section to a solid, square-shaped bar. This structure is clearly visible at the break across the shaft. It also appears that the central rectangular portion of the cross is composed of at least two other pieces of iron, welded onto the square bar. This complex construction is undoubtedly a contributing factor to the aggressive corrosion in the area of the PR orb and the center portion of the cross. Although distressing in terms of maintaining the integrity of the cross as an object, the opportunity to investigate its internal structure is of value for historical and technical research.

Figure 2: The cross in 1992 after initial treatment.

The cross is composed of a shaft and four open-work orbs. Two of the orbs are formed around the vertical shaft, and the other two orbs form the horizontal arms. The shaft starts with two tangs (skewed off-center) attached to the base of a circular, hollow socket. The socket extends into the lower orb, where the shaft becomes a solid rod, circular in cross-section. This rod changes to a bar (square crosssection) at the junction of the shaft and the rectangular middle section of the cross. The bar continues through the top orb, terminating in a decorative finial. This crowning finial is flat in cross-section, highly corroded, and appears to have been forged from the solid iron bar. Each orb is made from six perforated bands of an iron/brass laminate, and each band is made from two pieces, joined in the center, possibly by brazing. The cross is made primarily from wrought iron, as determined by analysis and by the complex structure as seen on the radiograph (Fig. 3). Traces of yellow gold on the outer surface indicate that the cross was once gilt. Bright lines visible on the radiograph suggest that the inside of the tangs, socket, and orbs are lined, likely with brass. Most of this interior lining is covered by corrosion, with only small areas of dull yellow metal actually visible where the corrosion has been removed. The cross was probably constructed using a wrought iron/brass laminate and then the exterior surfaces were gilded. It was difficult to tell from the radiographs exactly how the rectangular, middle section was welded around the central bar. It is also not clear how the orbs were attached to form two arms, but on the PL arm there appeared to be a socket holding the orb in place. The connection on the PR arm was highly corroded, with very little or no metal in the area between the orb and central, solid portion of the cross, but there appears to be a remnant “shadow” of a similar, cuplike structure to that on the PL orb. There had also been losses to both orbs comprising the arms. A knob at the distal end of the PR orb looks as if it had something snapped off at that point. The PL orb lacks this extension, and is hollow at precisely that spot. It is possible that both orbs anchored other elements which would have completed the arms.

Figure 3: Radiograph of the cross.

Figure 4: The cross in 4 pieces as of November 2004.

Historical context The Colony of Avalon, founded at Ferryland in 1621 by Captain Edward Wynne on behalf of its proprietor, George Calvert, the first Lord Baltimore, was one of several English colonies established in Newfoundland by entrepreneurs hoping to glean profits from a thriving

Details of the cross’s construction not apparent on the radiograph were revealed recently as a result of active corrosion. This corrosion has caused the cross to separate into four pieces plus a fragment (Fig. 4). The PR orb and the lower portion of the shaft are now detached from the 128

JUDITH A. LOGAN, ROBERT L. BARCLAY, PAUL BLOSKIE, CHARLOTTE NEWTON, AND LYNDSIE SELWYN: SAVING THE FERRYLAND CROSS seasonal fishery. Calvert, a Catholic convert who purchased a portion of the Avalon Peninsula, had intended his colony to be not only a source of personal profit, but also a place where both Protestants and Catholics could practice their religious beliefs. As such, the colony was unique in the New World.

Archaeological context Although the site was continuously inhabited since its founding in 1621, the precise locations of the buildings comprising the early settlement were lost over time. Test excavations in the 1930s, 1950s and late 1960s uncovered tantalizing hints of the original colony, but it was not until the mid-1980s, when Dr. James A. Tuck began systematic excavation, that the full archaeological potential of the site became apparent (Tuck 1996).

Under the direction of Captain Wynne, a group of colonists arrived at Ferryland on August 4, 1621, and set about building fortifications, living quarters, and other functional structures. Within the first year of its founding, the Colony of Avalon had a forge, a well, a wharf, and a large building with living space including a kitchen and hen house (Pope 1996). The forge would have been a key facility for making and maintaining the variety of tools and hardware necessary for construction of buildings as well as activities such as fishing, raising livestock, and tending gardens (Carter 1997).

The site at Ferryland is rich in architectural and artifactual remains which reflect the relative wealth of the colony. Unlike the early colonies along the New England coast, which were established by Puritans and Quakers seeking refuge from religious persecution, 17th-century Ferryland was governed under the auspices of two wealthy families, both with royal favor: first the Calverts, then the Kirkes. The layout of the early colony was carefully planned, with cobble streets, drains, and buildings of wood and dry stone construction, roofed with slate. Sites with architectural remains pose interesting scenarios for the preservation of materials. Foundations, pavements, and modified landscapes create micro-environments, the chemistry of which is reflected in metal corrosion products as well as overall preservation of different classes of materials. Ferryland is a coastal site, surrounded on two sides by salt water. Parts of the site are waterlogged, whereas others are reasonably well-drained. Preservation of textiles, other organic materials and composite objects has given an unusual glimpse at the richness of 17th-century material culture (Mathias and Foulkes 1996; Mathias et al. 2004).

After visiting Ferryland in 1627, Calvert spent one year (1628/29) at the Colony of Avalon, bringing his family with him, along with a fresh group of colonists and two priests. Historical records indicate some friction between the Catholics and Protestants, as well as a particularly harsh winter during which several people died (Calvert 1629). Calvert was in communication with Charles I in August of 1629, announcing his intention to quit the colony in favor of the more benign climate of Virginia (Calvert 1629). Calvert’s sons later established colonies in what is now Maryland. In 1638, Charles I granted the Island of Newfoundland to Sir David Kirke, who had served England by conducting a successful campaign against the French in Quebec, defeating first the French Navy in 1628, followed by the surrender of Quebec in 1629. Kirke, an Anglican, took up residence at Ferryland, which became Newfoundland’s capital with Kirke as governor.

The artifact assemblage is distinguished from other early colonial sites by evidence of wealth in the form of high quality ceramics, coins, and artifacts incorporating precious metals: gold- and silver-wrapped threads preserved in scraps of textile; three gold rings, one a part of a hoard that contained seven silver coins; tin-plated and silver pins; beads, buttons, and spurs plated with precious metal; enameled objects, such as a remarkable set of 22 karat gold seals, identified as the personal property of David Kirke (Inkpen 2005); and of course, the Ferryland Cross.

The execution of Charles I (1649) and the establishment of Cromwell’s parliament saw a change in Kirke’s fortunes. A strong Royalist, Kirke’s loyalty to the new government was suspect. In 1651, Kirke’s property was confiscated and he was recalled to England. At that time, John Treworgie, a Puritan from Massachusetts, was appointed as one of six commissioners to oversee Newfoundland. Treworgie took on the role of governor of Newfoundland, a position he held until 1660.

Treatment options The Ferryland Cross arrived at CCI in 1985 in a highly and unevenly corroded state, with cracks visible throughout its structure. The corrosion was hard and glassy, covering traces of gilding on what approximated the original surface of the metal. At that time, it was decided to use the least invasive approach to take off the rocks, sand, and extraneous debris; this involved using mechanical methods to clean down to the layer holding flecks of gilding.

Where the cross was made and what religious connotations it holds are not known. What is known is that it was lost or discarded at a time when Puritan influence in the English colonies was strong. Ostentatious trappings, such as a goldplated cross, would not have found favor with a zealous Puritan (Tuck and Robbins 1986). Could the cross have been part of Kirke’s property, seized and discarded when Kirke was recalled to England? Who owned the cross, whether it was used in Catholic or Anglican ceremonies, and why it was discarded may never be known.

At the time, it was recognized that mechanically removing the corrosion did not address the issue of salt removal. The cross would still have had salts deep in the intergranular zones and next to remaining metal, where chloride ions typically concentrate (Selwyn et al. 1999). One approach to chloride ion removal would have been to use electrolytic reduction to increase the porosity of corrosion products, but 129

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS it was considered too dangerous due to the risk of the cross falling apart. The presence of brass as a lining in the orbs and socket precluded the use of alkalis (such as sodium hydroxide or sodium carbonate) to promote chloride ion removal because of the danger of dissolving the copper alloy (Pourbaix 1974; Selwyn 2004). A more neutral solution of sodium sesquicarbonate could also have put copper into solution (Weisser 1975). Furthermore, any chemicals used would have had to be completely removed, another unknown factor, given the object’s complicated structure and condition.

adhesives to hold the three main pieces in their correct alignment. This would meet the goal of keeping the broken edges, which revealed details of the cross’s construction, accessible for future examination. It also allowed very accurate alignment of the pieces without putting stress on the fragile breaks.

Rather than risk the use of electrolytic reduction or alkaline solutions, we decided to adopt the more benign approach of washing the cross in a soxhlet apparatus in an atmosphere of nitrogen to promote the removal of salts (Scott and Seeley 1987). We were aware that this would not remove chloride ions from deep in the structure. Maintaining the cross in a dry environment would be fundamental to its long-term survival. Recent laboratory experiments modeling the corrosion problem of archaeological iron contaminated with chloride ions demonstrated the need to maintain the relative humidity below 19% to prevent ongoing iron corrosion (Watkinson and Lewis 2004).

Reproductions 3D Laser scanning Laser scanning technology was used to make a highresolution three-dimensional color digital record of the cross. This 3D imaging technology was developed by the National Research Council of Canada and has been licensed to Arius3D of Mississauga, Ontario for commercial application (Taylor et al. 2003). Arius3D’s laser scanning system consists of a laser (with a focused beam consisting of three wavelengths: red, green, and blue) and a motion control system for moving the laser. The laser scanning of the cross was done at the 3D Imaging Centre of the Canadian Museum of Nature in Aylmer, Quebec using Arius3D’s system. Each of the four pieces of the cross was scanned separately.

We decided to adhere the section of broken tang with Lepage’s 5 Minute Epoxy resin, and reinforce the thin break with A and B Epoxy Putty. This repair should hold the tang at its correct angle without further support.

Over the past 20 years since the cross was excavated, it has been returned to CCI several times for observation and interventions, as summarized in Table 1. New cracks have formed over the years and active corrosion has been noted. It is still actively corroding, and even if it were possible to remove salt from the corrosion layers, the different metals and metallic structures in contact with each other will make it difficult to halt future corrosion. After the PR orb became separated from the rest of the cross in 2003, it became clear that the cross had to be recorded threedimensionally in order to have a permanent record of its condition. Fresh breaks in 2004 had also exposed details of the construction of the cross. This information had to be recorded and the breaks had to remain accessible should researchers wish to examine the structure. The most problematic breaks occurred in the area of most active corrosion, which, predictably, is in the center, where several different structures come together. This is also the area where the mass of metallic iron is located.

For each piece, sequential overlapping scans were collected until the entire surface had been covered. For each scan, the laser beam was passed over the surface, one line at a time, and data collected at 0.004-in. (100 μm) increments, producing a grid pattern of the object’s surface geometry. The data collected at each position in the grid involved six parameters: three for the position of the point in threedimensional space (along x, y, z axes); and three for the color of the reflected light (red, green, blue). About three days were required to carry out the scanning and collect the data, with approximately 100 scans needed for each of the larger pieces. Once the scanning data had been collected, it was then processed using Arius3D software (Pointstream 3DImageSuite software) to create 3D images. For each piece, the 3D image was created by alignment of individual scans using overlapping areas between adjacent scans. The 3D images for each piece were then merged together to make a single 3D image of the complete cross (Fig. 5). Data manipulation to produce the final images took about 10 days.

One of the difficulties in monitoring the episodes of active corrosion was getting accurate, reproducible data of the development of cracks. The complex shape made standard measuring techniques, such as using a scale in the ocular of a microscope, impractical. Photography and radiography had been used extensively to monitor condition, but again, it was difficult to produce measurable, comparable images. Molding the cross had been considered, but we were concerned that any molding process would damage the cross. We decided to use the technology of 3D laser scanning and 3D printing to make three-dimensional reproductions of the cross, an approach that allowed us to safely record and reproduce it. The added bonus of this approach was that a reproduction could be used to make a form-fitting support for the original pieces, thus eliminating the need to take a mold from the original cross or use

The final digital images of the separate pieces and the complete cross were provided in various data formats so they could be viewed using different 3D viewing software. One data file format was PSI which contains the data point information (i.e., the six parameters x,y,z,r,g,b) and is best viewed using the Pointstream viewer, available for free from Arius3D. Another data file format was POL which contains the data reformatted into triangles and best viewed using Imview, available for free from Innovmetric software. The data was also provided in the data file format 130

JUDITH A. LOGAN, ROBERT L. BARCLAY, PAUL BLOSKIE, CHARLOTTE NEWTON, AND LYNDSIE SELWYN: SAVING THE FERRYLAND CROSS STL (i.e., stereolithograph) which is suitable for making digital reproductions.

Figure 6: Plaster based reproduction of the cross using 3D printing technology.

Dry anoxic display case Given the inherently unstable nature of the cross, a dry anoxic environment for storage and display was essential to its long-term survival. In order to retard corrosion as much as possible, the Ferryland Cross needed to be sealed in an airtight enclosure with oxygen and water vapor removed. Escal gas barrier film and RP-A oxygen/water vapor absorber were chosen for this.

Figure 5: Electronic reconstruction of the cross using 3D laser scanning technology.

3D printing Three-dimensional printing technology was used to make three high-definition plaster-based reproductions (also called 3D prints) of the cross. This technology was developed at MIT and has been licensed to several companies. The reproductions of the cross were made by the Academic Information & Communication Technologies (AICT) of the University of Alberta in Edmonton, using a Z400 3D printer from Z Corporation and the digital STL file of the cross (Hartigan 2003). The printer can make reproductions as large as 8 x 10 x 8 in. (203 x 254 x 203 mm).

Escal is a laminate of clear polypropylene lined with polyvinyl acetate to which a layer of transparent ceramic is vacuum-deposited. An inner layer of polyethylene completes the laminate and allows the sheet to be heatsealed. The film has a slight yellow tinge but is transparent. The ceramic layer imparts Escal’s gas barrier quality. RP-A oxygen/water vapor scavenger is composed of mordenite, calcium oxide, unsaturated organic compounds, polyethylene and activated carbon, enclosed in a vaporpermeable sachet (Mathias et al. 2004b). Both Escal and RP-A are manufactured by Mitsubishi Gas Chemical Company.

The 3D printer gradually built each model of the cross, one layer at a time, working from the bottom up. First, a thin layer of a plaster/resin powder (ZP 100 powder) was spread over the printing area. Then a cross-section of the model was “printed” onto the powder by the 3D printer (with its inkjet printer head) with drops of a water-based mixture (ZB 7 binder) instead of ink. Wherever the plaster/resin mixture was touched by the water-based mixture, it hardened, creating a solid cross-section of the cross. The printing area was then lowered 0.004 in. (0.1 mm), a new layer of powder was spread over the hardened section, and the process repeated until the 3D model was complete. After each model was finished printing (a process that took about three hours), it was left overnight to dry, and then removed from the machine. The final step involved excavating the model from the surrounding unhardened powder followed by gentle cleaning. Figure 6 contains an example of the 3D model.

On-site experience with the Escal system showed that it was relatively simple to maintain the enclosure with the minimum of specialized tools and expertise (Mathias et al. 2004b). In view of the facilities and resources at the display location in Ferryland this was an important consideration. Because of the airtight sealing, inert materials of known long-term stability were chosen for constructing the display enclosure and mount. Mounting the three sections of the cross required a formfitting base which would provide maximum support of the under surface of the sections. RTV silicone rubber (TinSil 70) was chosen for making the base because of its ability to replicate shapes accurately and its known long-term stability. One of the 3D prints was used as a model for making the base. It was wrapped in Parafilm—a thin, stretchable paraffin wax film—to protect it and to close its many undercuts, and then placed in a square mold. The mold was built from Lego bricks, which provide an easily adaptable and reusable material for making molds. The wrapped model was centered in the mold and the silicone rubber poured around it. Once the rubber cured, the model was eased out, leaving a very accurate impression of its shape. A surround and support for the rubber base was built of Plexiglas. This provided support for the flexible rubber while also allowing for attachment of covering material.

The plaster models were strengthened with low viscosity, clear epoxy (EPO-TEK 301). The epoxy was applied using a medicine dropper and rapidly soaked into the plaster. The plaster models increased about 45% in weight during consolidation. The reproductions were inpainted with acrylic artist’s color to match the color of the cross.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS safely at their destination, the pieces were aligned correctly on the silicone support. The display case with RP-A in an Escal enclosure was assembled on-site. The cross went on display at the Colony of Avalon Visitor Centre during the summer of 2005.

The visible parts of the support were covered with grey sueded polyethylene with a self-adhesive acrylic backing. A Plexiglas inner lid 7 x 8 in. (~18 x 21 cm) was made to fit over the support (Fig. 7.)

Conclusions Since its discovery in 1985, the cross has been the signature artifact for the Colony of Avalon. Its inherent instability, combined with the need to have it on display and available for study has made recording and replicating the object in its present condition essential. The creation of an inexpensive, easy to maintain, inert display/storage environment is crucial for its survival. A preventive conservation approach met these objectives: a) Recording its condition using 3D laser scanning has generated accurate, reproducible, mathematical data of its condition. b) Using 3D scanning and printing to create accurate reproductions of the cross has allowed a model, rather than the original artifact, to be used as a mold for a custommade support. The support, in its protective enclosure, has made it possible to accurately align the pieces of the cross and hold them in place, without adhesive. This serves two functions: i) researchers will have access to study its internal structure, and ii) since no adhesives have been used on the breaks around the central portion, it will be possible to quickly recognize and document any change, such as active corrosion. c) Using commercially available products, the gas barrier Escal coupled with RP-A, an oxygen and water vapor scavenger, it is now possible to keep the cross in a costeffective, easily maintained environment that should halt or retard active corrosion.

Figure 7: The Ferryland cross on its new silicone rubber support

A bag was constructed of two 14 x 19 in. (35 x 48 cm) sheets of Escal heat-sealed to each other along three sides. The display case was then placed in the bag. The approximate volume of the bag with the display case inserted was 330 in3 (~5.4 L). The RP-A absorber is available in different sizes, each size formulated to remove oxygen from a different air volume, with the sizes ranging from RP-1A for 6 in3 (100 ml) of air, to RP-20A for 122 in3 (2,000 ml) of air (Mitsubishi 2005). In order to ensure full absorption it is advisable to exceed slightly the number of sachets calculated for the volume of the bag. Ideally, we would have liked to use RP-20A because only three sachets would have been needed. In practice, we used 20 sachets of RP-3A because of price and availability. An RH indicator strip was also inserted into the bag; this would provide a visual reference to water vapor absorption, and by inference give an indication that the bag remained sealed. The bag was then quickly heat-sealed along the fourth edge. Wrinkling and contraction of the bag over the next few hours indicated that the RP-3A was absorbing the oxygen from the air in the sealed enclosure. A loose-fitting outer cover of opaque grey Plexiglas, with a window slightly smaller than the inner lid, was placed over the bag assembly, thus concealing everything except the cross and its mount. In future, in order to ensure minimum optical distortion, the wrinkles to which Escal is prone can be minimized by stretching it over the Plexiglas inner lid using strips of double-sided archival tape. The display case can then be inserted into the bag, the protective strips of the double-sided tape peeled off, and the Escal stretched over the lid and pressed down.

Although we may never know the origins of the cross, perhaps because of its enigmatic history, it remains an object of fascination for both the public visiting the Colony of Avalon and for historians. Acknowledgements The authors wish to thank the following people: Chris Want and Dr. Irene Karsten at the University of Alberta, Dr. James A. Tuck and Cathy Mathias at Memorial University of Newfoundland, the Colony of Avalon Foundation, Arius3D, and Carl Bigras and Jeremy Powell at the Canadian Conservation Institute. Bibliography Bokman, W., and M. Laver. 1985. Ceremonial Cross from Ferryland Newfoundland. CCI Analytical Report ARS 2421. Ottawa: Canadian Conservation Institute. Calvert, G. 1629. Sir George Calvert, Lord Baltimore, Letter to King Charles I, dated 19 August 1629. Available from http://www.heritage.nf.ca/avalon/history/documents/letter_ 14.html (accessed August 15, 2005).

The resultant construction provides an aesthetically attractive display enclosure that is also easy to maintain. While Escal is not as transparent as glass or Plexiglas, and has a slight yellow cast, stretching it across a flat surface minimizes the effect.

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EPO-TEK 301 Epoxy Technology 14 Fortune Drive Billerica, MA 01821-3972 (800) 227-2201 or (978) 667-3805 Web site:

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Selwyn, L.S., P. Sirois, and V. Argyropoulos. 1999. The corrosion of excavated archaeological iron with details on weeping and akaganéite. Studies in Conservation 44: 217– 232.

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Sirois, J. 1995. Analysis of Yellow Metal on a Gilded Iron Cross. CCI Analytical Report ARS 3426. Ottawa: Canadian Conservation Institute.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS (609) 397-1131 Web site: TinSil 70 RTV Silicone Rubber Polytek Development Corp. 55 Hilton Street Easton, PA 18042 (800) 858-5990 or (610) 559-8620 Web site: Biographies Judy A. Logan studied archaeology and English at the University of Calgary (BA 1971), apprenticed in archaeological conservation at Parks Canada, and received a Master of Art Conservation degree from Queen's University, Kingston, in 1978. She joined the Canadian Conservation Institute in 1981, where she is presently a senior conservator specializing in archaeological material. Robert Barclay has a certificate in Science Laboratory Technology from the City and Guilds of London. He graduated from the University of Toronto with an Honors Degree in Fine Arts, and has a PhD from the Open University in the United Kingdom. He has worked at the Canadian Conservation Institute of the Department of Canadian Heritage since 1975. Paul Bloskie graduated from Carleton University (B Com Hons 1993) with a concentration in Information Systems. He joined Arius3D in 2000 as an Imaging Specialist and continued with the company spin-off XYZ RGB before joining with the Museum of Nature as Senior Technician in 2003 for the opening of their 3D Imaging Centre. Charlotte Newton studied Art History at Queen's University (BA Hons 1975) and obtained a Diploma in Archaeological Conservation from the Institute of Archaeology, University of London in 1983. She began working in the Conservation Division of Parks Canada in 1977 and joined the Archaeology lab at the Canadian Conservation Institute in 1986, where she is presently a senior conservator. Lyndsie Selwyn graduated in 1985 from the University of California at San Diego with a PhD in Physical Chemistry, followed by postdoctoral research at the National Research Council of Canada in Ottawa. In 1987 she joined the Canadian Conservation Institute where she is presently a senior conservation scientist. Her research focuses on the corrosion and conservation problems associated with metals. Address Canadian Conservation Institute 1030 Innes Road Ottawa, ON K1A 0M5 Canada

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MIMBRES CERAMICS ANALYSIS: INTEGRATING CONSERVATION WITH ARCHAEOLOGICAL RESEARCH Landis Smith Abstract The potential for integrating conservation with archaeological research has been demonstrated in several recent projects involving Mimbres ceramics. In particular, aspects of archaeological ceramics analysis are closely aligned with conservation in a common focus on technology and materials studies. While the ultimate goals of the conservator and ceramics analyst differ, the study and documentation of the physical characteristics of systematic collections or site assemblages are common to both. Particularly as excavated collections are re-documented and re-analyzed, the information recorded by conservators can be integrated with the language and concerns of ceramics analysis. The opportunity to more fully integrate archaeological inquiry with conservation documentation and research has developed from a small refiring experiment with Mimbres sherds to a large, multi-museum survey project involving Mimbres collections of whole vessels. In each case, the conservator’s work has been guided by both conservation and archaeological questions; the results of these projects, then, contribute both to the preservation of Mimbres ceramics and to the archaeology of Mimbres culture.

longer identifiable and the Mimbres pottery no longer produced. Classic Mimbres pottery consists largely of coiled and scraped bowls, slipped and painted, then fired in a neutral reducing, and sometimes oxidizing, atmosphere. Clays were apparently gathered locally, minimally processed, and tempered with volcanic ash or stream sand (Gilman et al. 1994). Despite the great numbers of pots produced, no kilns have yet been found at any Mimbres site. Most of the bowls are hemispheric in shape, about 6 to 12 inches in diameter, with roughly finished exteriors (Fig. 1) that contrast dramatically with the meticulous and stunning artistry of the interiors. The interiors of these bowls have been described as ‘whiteslipped canvases’ (Brody 2004) against which were painted stylized animals, humans, and anthropomorphic figures, as well as geometric designs (Fig. 2). The meaning and significance of these images is a subject of much conjecture, though scholars such as J.J. Brody (2004) and Steven LeBlanc (LeBlanc 2004; LeBlanc and Ellis 2001) have drawn theories about the daily and ritual life depicted. The bowls have been excavated from both household and funerary contexts, with many, but not all, of the funerary bowls having been intentionally punched through near the center (Fig. 3). These holes are commonly referred to as ‘kill holes’ and are believed to have been made as part of interment rituals. Their precise meaning and purpose are as cryptic as Mimbres imagery. However, one theory posits that the hole punched in the bowl allowed the spirit of the deceased to travel to the next world. Hence the alternative, and perhaps more accurate term used by some Pueblo people today, ‘breath hole’ (Brody and Swentzell 1996).

The Mimbres and Classic Phase ceramics Considered a branch of the widespread Mogollon culture area of the American Southwest, the Mimbres developed their own recognizable culture in southwestern New Mexico by about 900–1000 AD. The Mimbres, or mimbrenos, lived in densely built villages, usually constructed over earlier pit houses, on sites that often show centuries-long occupations. Mimbres villages were largely located along the Gila and Mimbres River valleys where irrigated subsistence farming, hunting, and fishing supported the population. The Classic phase of Mimbres culture fluoresced during a relatively short period of about 150 years, from approximately 1000 to 1150 AD, and is largely characterized by the prolific production of a unique and aesthetically striking pottery type. About 1130 AD, evidence of significant changes in Mimbres life is seen in shifting demographics, architecture, and pottery. Although population estimates vary greatly, it is known that large sites were depopulated and smaller hamlets occupied. As people moved to the north, and, as evidence suggests, to the south to the large Cases Grandes town of Paquime, the dispersion and abandonment of Classic Mimbres ceramics accelerated as well (Ennes 1999). The reorganization and movement of Mimbres people during the Postclassic period is well established (Hegmon 2002) but the reasons for it are still debated. Theories include insufficient resources to support populations along with soil and large mammal depletion, a severe 15-year drought (Minnis 1985) and possible social oppression (Hegmon et al. 1998). By 1150, a discrete, recognizable Mimbres culture was no

Figure 1: Mimbres Classic Black-on-white bowl, exterior (Style III, c. 1000–1130/1150 AD). National Museum of Natural History, Smithsonian.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Mimbres designs appears in the renowned black-onblack pottery of Julian and Maria Martinez in the early 1920s; the designs now appear ubiquitously, from dinnerware to tourist t-shirts, business logos, architectural details, and contemporary Pueblo pottery. Mimbres pottery has been the subject of many exhibits and publications, increasing its popularity and creating an active market. This unfortunate and mostly illegal market is fed by active looting of Mimbres sites. Despite state and federal laws enacted to protect sites, pothunters have continued to ravage the landscape in search of the valuable pottery. It seems likely that the vast majority of Mimbres sites have been irreparably disturbed (Turnbow 2001). In recent decades, it has been observed by the author and others that the use of backhoes and bulldozers to create channels through the center of suspected sites has accelerated the destruction (Turnbow 2001; Brody 2002).

Figure 2: Mimbres Classic Black-on-white bowl (Style III, c. 1000–1130/1150 AD). National Museum of Natural History, Smithsonian.

Mimbres archaeology and museum collections Although Mimbres sites were long known to residents of southwestern New Mexico and dug for recreation for many years, it can be argued that the first great wave of pothunting was unintentionally generated by Smithsonian archaeologist Jesse Walter Fewkes in 1914. At the invitation of amateur archaeologist E.D. Osborn, Fewkes traveled to New Mexico where he purchased the first significant museum collection of Mimbres ceramics. Osborn had excavated his collection of painted pots on his family’s ranch, apparently out of interest and without any mercenary motive. However, word spread quickly that Fewkes had paid a sum of $150 for a group of 21 pots (Fewkes 1914), and the market was soon flooded, feeding the demands of private collectors and museums alike. Looting of sites on both private and Federal land has continued, with a sharp increase in activity in recent decades as market value has increased. While federal and state laws, and later the Native American Graves Protection and Repatriation Act (NAGPRA), have forced much dealing underground, it continues apace. Ironically, as Mimbres culture is brought to the public through museum exhibits and publications, the demand for pots has increased, resulting in further destruction of potential sites and information.

Figure 3: Mimbres Classic Black-on-white bowl (Style III, c. 1000–1130/1150 AD). Museum of Indian Arts and Culture. Kill hole. No use wear. Highly polished paint.

Repatriation and cultural sensitivity issues are complex for Mimbres ceramics; there is no proven descendant population, although oral history and archaeological evidence certainly indicate that the Mimbres were dispersed and became part of today’s Pueblo populations. There are also uncertainties of burial context associated with poorly documented older collections.

Many major museum collections of Mimbres ceramics were formed through private donations during the early part of the 20th century, and therefore lack documentation beyond perhaps the name of the ranch from which the pot was taken. In fairness, archaeology was still in its infancy, without the methodical and scientific approach of archaeological work today. Exceptions included the careful excavations at Swartz Ruin by Cornelius and Hattie Cosgrove under the aegis of Harvard Peabody Museum (e.g., Cosgrove and Cosgrove 1932), and the Cameron Creek site excavated by archaeologist Wesley Bradfield of the Laboratory of Anthropology, Museum of New Mexico, Santa Fe, New Mexico. Bradfield, along with his colleague, ceramics specialist Anna O. Shepard, produced exceptionally thorough reports of the methodical and carefully documented excavations at Cameron Creek, setting new

Further complicating repatriation issues is the unavoidable reality that Mimbres images and designs, however sensitive they may be (and we may never know), have become part of the contemporary Southwestern landscape and beyond. The impact of this relatively small and short-lived culture on modern aesthetics 1000 years later is remarkable. Mimbres motifs and images have been widely incorporated in today’s generic southwest style by both Native and nonNative people alike. The first broad-based use of 136

LANDIS SMITH: MIMBRES CERAMICS ANALYSIS campaigns of reconstruction, filling of losses, and inpainting or overpainting. While the reassembly of sherds has doubtlessly preserved pots that were once in pieces, some restoration has damaged both the physical and cultural integrity of many bowls. Perhaps the most glaring example is the filling and inpainting of kill holes (Fig. 4). This is a surprisingly widespread phenomenon, mostly carried out many years ago. In other cases, the restorer, in an effort to present ‘whole’ pots, used his or her artistic license in ‘completing’ designs or figurative images. A prime example of this is seen in a pot at the Museum of Indian Arts and Culture/Laboratory of Anthropology that shows two men interacting over items they are holding, perhaps trading. However, the central portion of this scene was filled, and then painted by a restorer, presumably a ‘best guess’ at the original image. Some past restorations also interfere with the research value of the pots as, for example, when original surfaces have been filled or overpainted, hiding wear patterns (Bray 1982) and undermining future compositional and other analysis.

standards for archaeology in their day (e.g., Bradfield 1929). Unfortunately many older collections lack this sort of documentation and are therefore currently of less research value. However, information gleaned at recent and current scientifically excavated sites can help to contextualize older collections. In particular, Texas A&M University archaeologist emeritus Dr. Harry Shafer’s ongoing excavation of the NAN Ranch site has yielded a great deal of important information including a more precise stratigraphy (Shafer 2003). Shafer and Brewington’s (1995) chronology based on microstylistic changes in Mimbres ceramics has been used to reclassify older collections. An example of such a project was led by archaeologist Christopher Turnbow, formerly at the Museum of Indian Arts and Culture/Laboratory of Anthropology (MIAC/LOA), Santa Fe, New Mexico, and now at the Maxwell Museum of Anthropology, University of New Mexico. The central role of ceramics in Mimbres archaeological research The study of ceramics, as opposed to other materials, is central to Mimbres archaeology. While much organic material has disintegrated, ceramics offer a reliable and extensive record of site occupation, technology, social organization, lifeways, trade, religion, collapse, and dispersion. Stylistic and technological changes in pottery help to date archaeological strata and trace other changes and cultural practices. As archaeologist Michelle Hegmon writes (2002), the Mimbres ceramic tradition ‘bridges the gap between…how people lived on the Mimbres landscape, and…how people dealt with each other and cosmos.’ Yet, surprisingly, as Hegmon points out, there have been very few large systematic studies of Mimbres ceramics to date. The first, if rudimentary, classification was put forth by J. Walter Fewkes in his Designs on Prehistoric Pottery (Fewkes 1925), and has been followed by other studies of Mimbres design and imagery, most notably of late, the work of J.J. Brody (2004) and Steven LeBlanc (2004; LeBlanc and Ellis 2001). While much attention and scholarly work has been given to Mimbres design, surprisingly little has been done in the area of technology, materials, or use wear. However, two such studies include Alicia Bray’s analysis of use wear in which she concludes that the lack of wear in finely made points may point to craft specialization within Mimbres culture (Bray 1982); and neutron activation analysis to study paste in sourcing and distribution (Gilman et al. 1994), which showed that there were many sources of Mimbres clay and the production was decentralized.

Figure 4: Mimbres Classic Black-on-white bowl (Style III, c. 1000–1130/1150 AD). National Museum of Natural History, Smithsonian. Filled kill hole. Use wear.

As for the damaging physical effects of past restoration, perhaps the most extreme examples include the severe, dark staining caused by the leaching of oily substances from old resinous fills as seen in the Cameron Creek assemblage at MIAC/LAO. It is known, after investigating the history of excavation and donations of pots with these same fill materials to the Cleveland Museum, that the fills were made in the 1930s. The staining has been reversed in a few pots in the past (Smith 1996), but a major effort to analyze and treat the entire collection has been recently and successfully carried out at the Museum of New Mexico Conservation Laboratory, led by conservator Mina Thompson and head of conservation Claire Munzenrider.

The conservation and restoration of Mimbres ceramics The high artistic value given to Mimbres ceramics has resulted in a great deal of treatment and restoration as the pots have been, and continue to be, widely exhibited, published, and photographed. Any cursory survey of Mimbres museum collections reveals extensive past

Fortunately, at many museums during the early 20th century, including at the MIAC/LOA, nitrocellulose 137

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS it is highly improbable that anything but a clay paint could withstand polishing (Blinman 2004) this characteristic is further evidence of the use of clay as paint. However, the exact compositions and forms are not known. For example, it is possible that an organic binder was added to increase flow of the paint from the brush, at least in some pots. It is also likely that paint compositions vary from one Mimbres area to the next, as does the paste (Gilman et al.1994).

adhesive (often Duco) was most often used to reassemble broken pots. Despite its instability, oxidized brown color, and deteriorated state, nitrocellulose adhesives remain easily reversible. Weakened or misaligned joins are fairly easily reversed and re-joined. It was during the treatment of these conditions in the early 1990s that an odd phenomenon was observed; in the course of removing old nitrocellulose adhesive with acetone on cotton swabs, minute amounts of a residue that matched the paint seemed to solubilize on cotton swabs as they were rolled over the paint surfaces. The residue was the exact same brown/black color of the paint, and if the paint was red, the swab also showed red. There were no discrete particles found on the swabs. This condition was observed independently by other conservators treating Mimbres pottery (Raphael 1999; Odegaard 2000).

Slips have also yet to be definitely sourced and analyzed, though preliminary X-ray diffraction shows a kaolin signature (Bischoff 2003); but there is much more to understand, as this characteristic is quite commonly seen in many white clays. Professional replicators of Mimbres pottery describe a source at natural springs near Mimbres sites, as well as the use of a hard volcanic ash for Salado reproductions. Based on geological knowledge of the area, smectite clays are likely.

Slip and paint To begin to understand the phenomenon of unstable paint, a closer look at the paint and its interface with the slip was needed. A preliminary test using a portable Xray diffraction unit was carried out in 1993 by a University of Arizona intern. The test showed, in a very limited sample, that the paint and paste were compositionally almost identical, while the slip was quite different. However, no systematic mineralogical analysis has been published to date. To address this, a study is currently underway by the author. What we do know at this point is that the black and red figures and designs on Mimbres ceramics clearly show the characteristics of a mineral paint in morphology and color. First, the paint lies in relief on the surface rather than having been adsorbed by the slip as would an organic paint. Further, the paint has well-defined, rather sharp edges, as opposed to the more blurry edges of an organic paint.

Knowledge of slip composition is important in understanding the behavior of paint during firing and its stability on the fired pot. Firing conditions are paramount, but the compatibility of the slip and the paint also greatly affects the successful fusion of mineral paint to the slip; or, in the case of organic paints, adsorption of the paint by the slip in firing. For example, an organic paint will not fire successfully if the slip is not sufficiently bentonitic, having a high shrinkage ratio upon firing. The interaction between the Mimbres slips, mineral paints, and firing conditions are not well understood, but planned compositional analysis should throw light on the subject. In addition, the behavior of paints is often best understood through other kinds of studies, including refiring experiments.

Specifically, iron is indicated by the color range of the paint, showing the effects of oxidizing and reducing atmospheres during firing. Both the oxidized red and reduced black are often seen in the same bowl where the kiln conditions may not have been perfectly controlled. In pots where the paint is completely red, it is believed that the red is intentional. The mineral is doubtlessly iron, which is everywhere in the Southwest, occurring in great abundance in a variety of forms. Iron paint on pottery appears in a number of forms in the Southwest; one example is as a naturally occurring, high iron content clay, usually mixed with water. This paint type can be observed in use by potters today, at Acoma Pueblo, for example. Other forms of paint include a potter’s mixture of ground hematite and clay; hematite in an organic binder such as Rocky Mountain Bee Plant (also referred to as beeweed); and iron-manganese clay paints.

Summary of refiring investigation A small refiring experiment was carried out by the author to investigate firing temperature as a possible explanation for the apparent paint instability of some Mimbres paint. To briefly summarize: it was theorized that the stability of the paint in Mimbres ceramics might be a function of firing temperature within the accepted range for Southwest pottery. Would the progression of sintering and vitrification be correlated with stability and hardness? It was also posited that the degree of polishing of the paint would be an important factor in paint stability. Other variables were also measured and correlated to explore possible associated factors; these included general surface conditions and evidence of use and erosion; Moh’s hardness measurements of the paint, slip and paste; and Munsell color chart readings of paint, slip, and paste.

The distinguishing characteristic of Mimbres paint is that it is usually polished. This is not seen in other black-onwhite ceramics in the southwest; the mineral paint traditions to the north of the Mimbres culture area, including the black-on-white pottery of the Ancestral Pueblo (Anasazi), do not polish their mineral paint. Since

Thirty sherds from the Saige-McFarland site were sorted by chronological phase and then tested for paint stability until the assemblage included 15 stable and 15 unstable samples. The paint colors ranged from black to red, and under magnification, the paint morphology varied greatly, indicating different paint compositions or 138

LANDIS SMITH: MIMBRES CERAMICS ANALYSIS essentially nonhierarchical society. Archaeologist Alicia Bray’s study of use wear in Mimbres ceramics (Bray 1982) led her to propose that some pots may have been status items and may have been treated differently than utilitarian pots. Similarly, the findings from the refiring experiment tentatively support the case for at least some decentralized craft specialization within the culture (LeBlanc and Ellis 2001), as well as Bray’s suggestion that the more finely made and painted pots may have been treated differently by Mimbres people.

varying degrees of polishing. Samples of 0.5 to 1.0 cm were refired at 50-degree intervals within the range of Mimbres kilns, 600–900°C; all measurements were taken and paint stability tested at each stage. To test for paint stability as it related to conservation treatment, acetone on swabs was rolled over surfaces for 30 seconds, approximating the amount of time needed to remove oxidized nitrocellulose from the pot’s painted surfaces. In the end it was found that paint stability in Mimbres pottery is not as much a function of firing temperature as it is of the extent of polishing of the paint. It follows that as the clay is compacted and the particles aligned, the bond with the slip is increased and hardness increased. Interestingly, some sherd samples that had been stable before firing became unstable after firing. The reasons for this are not well understood; iron paints are complex in their particular compositions and thermal transformations (Kay 1994). New compounds are formed as firing temperatures increase, but these compounds are not necessarily stable. Stable end products usually do not form until the temperature reaches about 950°C (Shepard 1956), a temperature that exceeds what is believed to be the range for firing temperatures in the ancient Southwest: about 600–800°C, possibly 850°C. However, stable phases of iron may be reached in the presence of other fluxes such as sodium chloride.

In the end, the need for a larger study of whole vessels was called for. Use wear cannot be effectively measured in sherds since use is manifested in characteristic patterns of wear over the whole pot. Mimbres pots are typically worn on the interior bases, often with a peripheral area of wear; there is often an area of exterior wear that corresponds directly to this interior wear. The lack of striations or dents in these areas suggests the use of a ladle rather than stirring or pounding implements; in addition, there are generally no residues or carbonaceous deposits that would indicate cooking. However, the specific use of the bowls is unknown, and in need of further study. Mimbres pottery projects and the development of the survey project As a result of the refiring experiment, a survey of whole Mimbres vessels was initiated. This would allow for correlations to be made between the level of use wear and the level of polishing as it pertains to paint stability. The study was planned in conjunction with the commencement of a large project in which older collections of Mimbres pots at the MIAC/LOA were being reclassified in light of recent microstylistic seriation. About 130 Classic Mimbres pots were surveyed for use wear, paint stability, and other physical characteristics including condition; observations were entered into the database as the pots were reassessed and new curatorial information entered. The method was integrated to some extent, but in the end there would be no way to make correlations between the variables without pulling the data catalogue card by catalogue card.

Other interesting quantitative correlations were made between the lack of use wear and/or erosion and a high level of polish of the paint (and therefore paint stability); conversely, there was also a strong correlation between sherds with unstable paint and significant use wear/erosion. One might argue that the reason for less use wear in the highly polished pots is that the paint is harder and therefore more resistant to certain types of damage during use. This seems obvious and is well documented in previous studies (Schiffer and Skibo 1989). But in measurements of the slips of 30 sherds, there was no difference in the hardness between them even while the paints varied in hardness. It would follow, then, that if finely painted pots were used as much, and in the same ways as less finely painted pots, the slips would show the same amount of wear and erosion. However, this was not the case in this study; in the 30 samples I measured, the slip was more worn on the lesspolished sherds. In other words, this experiment suggests that more carefully made pots seemed to have been used less. However, sherd samples cannot be adequately analyzed for use wear as this type of damage occurs as a pattern that can only be adequately observed in whole vessels.

During this same period, a long-discussed conservation project was being planned to reverse the severe staining that had resulted from unstable materials used in past restorations of the MIAC/LOA Bradfield collections of Mimbres pots. The project would require a conservation survey of the Mimbres pots. The confluence of the reclassification project, the paint stability and use wear study, and the conservation survey presented an opportunity to synthesize efforts. At the same time, discussions with archaeologists suggested that data generated by the survey could potentially be used to explore the idea of status items and craft specialization in Mimbres society. The conservator’s skills and knowledge lend themselves easily to the kinds of scientific measurements and observations required in certain types of ceramics analysis. By incorporating the language and questions of the archaeologist, the

The results of this small investigation into Mimbres paint stability may be of interest to conservators working with these objects, but could the data be useful to archaeologists as well? Although the sample was too small to be statistically significant, the findings certainly show strong enough correlations to justify further and larger studies of use wear and pottery technology. Such studies address a number of questions including those of craft specialization and the presence of status items in an 139

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS other museums as well as new data and categories of data can be added at any time. While the core of the survey is consistent across the museums, each museum can customize the form to address its particular needs.

definition of the conservation survey is expanded while fulfilling the purpose of the conservation assessment. Potentially, this kind of survey would contribute not only to the conservator’s ability to plan conservation of Mimbres pot collections, but would also contribute to the ‘big picture’, providing data that could help answer questions in Mimbres ceramics analysis and archaeology.

The sample is preferably systematic, that is, the best documented whole collections and site assemblages from controlled excavations. As discussed above, this is not always possible for Mimbres ceramics collected in the early 20th century, but if there is an option to survey a whole site as opposed to undocumented or small numbers of pots from various sites, the whole site should be surveyed so that the survey is as systematic as possible.

Conservation survey design Given the reality of museum resources, a survey must be carried out within the limitations of time, budgets, and expertise. While a much more extensive survey of Mimbres ceramics would include design analysis and other kinds of observations, this survey is necessarily narrower in focus, drawing on the expertise of the conservator in documenting technological aspects of the ceramics. The goal of the survey design is to create a data set that is truly useful to both the conservator assessing the collections, and to archaeologists doing certain kinds of ceramics analysis.

On a practical level, real limitations of time and money dictate that the survey not take significantly longer than a more conventional conservation survey. This means that the survey should require a minimum of new training and new background information for the conservators; hence the focus on technology rather than, for example, design.

To that end, the survey design must meet certain criteria. First and foremost the survey must be guided by larger archaeological questions to ensure the inclusion of relevant data. If the survey design begins with the research questions, the design will then follow logically. Secondly, the survey uses the terminology of ceramics analysis rather then terms more commonly employed by conservators. Terms for paste, slip, paint, temper, nonplastic inclusions, use wear, firing margins, and so on are aligned with those used in Southwest archaeology in order to better integrate the work and to facilitate communication.

Next, in order for the survey for to be useful in the final analysis, it must be quantitative; that is, each observation and measurement is organized as a menu of variables, and each variable assigned a number. For example, the presence of a kill hole is given a value of 1 in that category, the absence of a kill hole a 2, and when it is unclear if there is a kill hole, as when a hole has been filled and inpainted, the variable is assigned a 3. When all the observations and measurements are quantified in this way, significant statistical correlations between variables can identify trends and indicate possible cultural patterns.

Progress report To date, Mimbres collections in three museums are included in the survey: the Museum of Indian Arts and Culture/Laboratory of Anthropology, Santa Fe, New Mexico; the American Museum of Natural History (AMNH), New York; and the National Museum of Natural History (NMNH), Washington, DC. Data collected by conservator Chris White, formerly at the Arizona State Museum, Tucson, was not recorded in Filemaker Pro, but the data is relevant and can be transferred. A first run of the survey was carried out for ten pots at the Museum of Indian Arts and Culture with conservator Mina Thompson and then-intern Angie Elliot. They helped to refine the survey design and establish standards of measurement, one of the greatest challenges of this type of multi-museum survey. The necessity of maintaining consistent standards of observation and measurement across the museums and from one conservator to the next cannot be overemphasized. Common training at the front end of each survey, monitoring of the survey process, along with reference kits of sherds and photographs help to ensure consistency. Objective measurements such as volume, and even color readings, are more controllable; but the more subjective categories of observation, such as the level of polish of the paint, are more difficult to standardize. The use of some variables are being evaluated for future survey work. Meanwhile, most of the data continues to be useful.

Quantitative analysis requires a sample large enough to be statistically meaningful. A number of Mimbres site assemblages are widely dispersed across the country and abroad. To gather a large sample, then, it follows that the ideal would be to collect data from various museums and then merge it in a common database. A flexible database would enable the Mimbres data to be manipulated so that any characteristic can be correlated with any other, from any participating museum. In addition, the database should be expandable, so that more collections from

Initial analysis of the pots surveyed at MIAC presents some intriguing data. Although the sample is too small to be statistically meaningful at this point, it is of great interest to find strong correlations between minor use wear, fine execution of painted design, high level of polish, figurative images, and excavation from a funerary context; and at the same time, correlations between high use wear, carelessly painted pots, geometric designs, and a household burial context. Among other archaeological problems, questions of specialization within this

The scope of the survey needed to be narrow enough to make comparisons meaningful; therefore, Mimbres Classic Black-on-white, style III, was selected as the height of Mimbres culture and ceramic production.

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LANDIS SMITH: MIMBRES CERAMICS ANALYSIS nonhierarchical culture will be addressed with a larger data set as a result of the survey.

Papers of the Peabody Museum of American Archaeology and Ethnology, Harvard University 15 (1).

Conclusion This survey project is a work in progress, as the design is refined and revised with each museum. Obviously there are many more possible variables than can currently be included in this rather short conservation survey form. Other variables in the survey include bowl volume, wall thickness, burial context (if available), the presence or absence of a kill hole, extent of surface finish (painting and polishing), extent of use wear, Munsell color of the slip, and many more. With a flexible and common database, there is the potential for other specialists to add more information. This could include more site data, design analysis, paste composition and characterization, as well as the forthcoming compositional analysis of the paints and slips. Data should be available to explore myriad possible correlations between many variables, including the ability to compare whole sites.

Ennes, M. 1999. Evidence for migration in the eastern Mimbres region, southwestern New Mexico. In Sixty Years of Mogollon Archaeology: Papers from the Ninth Mogollon Conference, Silver City, New Mexico, ed. S. Whittlesey, 127-134. Tucson: SRI Press.

It is anticipated that more Mimbres collections will be surveyed to increase the database with the goal of conserving collections, and ultimately learning more about the Mimbres. The integration of archaeology and conservation in the area of ceramics analysis is entirely feasible and of benefit to the pots and what they can tell us about Mimbres culture.

Fewkes, J.W. 1993. The Mimbres: Art and Archaeology. Albuquerque: Avanyu Publishing.

Fewkes, J.W. 1914. Archaeology of the Lower Mimbres Valley, New Mexico. Washington, DC: Smithsonian Institution Press. Fewkes, J.W. 1919. Correspondence (1919), accession folder, Anthropology Department, National Museum of Natural History, Smithsonian, Washington, DC. Fewkes, J.W. 1925. Designs on Prehistoric pottery from the Mimbres Valley, New Mexico. Smithsonian Miscellaneous Collections, Vol. 74, No. 6: 1-47.

Gilman, P., V. Canouts, and R. Bishop. 1994. The production and distribution of classic Mimbres Black-onwhite pottery. American Antiquity 59 (4): 695-709. Hegmon, M. 2002. Recent issues in the archaeology of the Mimbres region of the North American Southwest. Journal of Archaeological Research 10 (4): 307-357.

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Blinman, E. 2004. Personal communication. New Mexico Office of Archaeological Studies, Santa Fe, NM. Bradfield, W. 1929. Cameron Creek Village, A Site in the Mimbres Area in Grant County, New Mexico. Santa Fe: School of American Research Press.

Kay, P. 1994. Analysis of five Anasazi mineral paint samples. Pottery Southwest 21 (2): 2-9.

Bray, A. 1982. Mimbres Black-on-white, Melamine or Wedgewood? A ceramic use-wear analysis. Kiva 47: 133-149.

LeBlanc, S. 1983. The Mimbres People: Ancient Pueblo Painters of the American Southwest. London: Thames & Hudson.

Brody, J.J. 2002. Personal communication. Department of Art History, University of New Mexico, Albuquerque, NM.

LeBlanc, S. 2004. Painted by a Distant Hand: Mimbres Pottery of the American Southwest. Cambridge, MA: Peabody Museum Press, Harvard University.

Brody, J.J. 2004. Mimbres Painted Pottery. Santa Fe: School of American Research Press.

LeBlanc, S., and M. Ellis. 2001. The Individual Artist in Mimbres Culture: Painted Bowl Production and Specialization. Poster presented at the 66th Annual Meeting of the Society for American Archaeology, New Orleans, LA.

Brody, J.J., S. Leblanc, and C. Scott. 1983. Mimbres Pottery: Ancient Art of the Southwest. New York: Hudson Hills Press.

Lekson, S. 2006. Archaeology of the Mimbres Region, Southwestern New Mexico. BAR International Series 1466. Oxford: BAR Publishing.

Brody, J.J., and R. Swentzell. 1996. To Touch the Past: The Painted Pottery of the Mimbres People: Essays. New York: Hudson Hills Press.

Minnis, P. 1985. Social Adaptation to Food Stress: A Prehistoric Southwestern Example. Chicago: University of Chicago Press.

Cosgrove, H., and B. Cosgrove. 1932. The Swartz Ruin: a typical Mimbres site in southwestern New Mexico.

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Munson, M. 2000. Sex, gender, and status: human images from the Classic Mimbres. American Antiquity 65 (1): 127-143.

Biography Landis Smith is currently Anchorage Project Conservator at the Anthropology Conservation Laboratory, National Museum of Natural History, Smithsonian, and a research associate with the Museum of Indian Arts and Culture/Laboratory of Anthropology, Santa Fe. Her work in New Mexico focuses on Southwest pottery and preservation issues with Pueblo potters and community members. Landis was project conservator for the Museums of New Mexico, Santa Fe for many years after establishing a conservation laboratory in the Dept. of Anthropology, American Museum of Natural History, NY.

Odegaard, N. 2000. Personal communication. Arizona State Museum, Tucson, AZ. Powell-Marti, V., and P. Gilman. 2006. Mimbres Society. Tucson: University of Arizona Press. Raphael, B. 1999. Personal communication. Southwest Conservation Laboratory, Santa Fe, NM. Rice, P. 1987. Pottery Analysis: A Sourcebook. Chicago: University of Chicago Press.

Address Anthropology Conservation Laboratory Museum Support Center National Museum of Natural History Smithsonian Institution Suitland, MD USA

Schiffer, M., and J. Skibo. 1989. A provisional theory of ceramic abrasion. American Anthropologist, New Series, Vol. 91 (1): 101-115. Shafer, H. 1995. Architecture and symbolism in transitional Pueblo development in the Mimbres Valley, southwest New Mexico. Journal of Field Archaeology 22 (1): 23-27. Shafer, H. 2003. Mimbres Archaeology at the NAN Ranch. Albuquerque: University of New Mexico Press. Shafer, H., and R. Brewington. 1995. Microstylistic changes in Mimbres Black-on-white pottery: examples from the NAN Ruin, Grant County, New Mexico. Kiva 64 (3): 5-29. Shafer, H., and A. Taylor. 1986. Mimbres Mogollon Pueblo dynamics and ceramic style change. Journal of Field Archaeology 3: 43-68. Shepard, A. 1956. Ceramics for the Archaeologist. Washington, DC: Carnegie Institution of Washington. Smith, L. 1996. Unpublished conservation reports, on file at the Museum of New Mexico, Santa Fe, NM. Steinbach, T. 2002. Mimbres Classic Mysteries: Reconstructing a Lost Culture Through Its Pottery. Santa Fe: Museum of New Mexico Press. Turnbow, C. 2001. Saving the Mimbres. Archaeology Southwest 15 (3): 2-4. Van der Weerd, J., G. Smith, S. Firth, and R. Clark. 2004. Identification of black pigments on Prehistoric Southwest American potsherds by infrared and Raman microscopy. Journal of Archaeological Science 31: 1429-1437. Woosley, A., and A. McIntyre. 1996. Mimbres Mogollon Archaeology. Amerind Foundation, Archaeology Series No. 10.

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NON-INVASIVE TECHNOLOGICAL STUDY OF ARCHAEOLOGICAL IRON OBJECTS Evelyne Godfrey Abstract The understandable reluctance of curators to allow samples to be cut from metal artifacts has limited the amount of technological information that can potentially be extracted from the objects. This is particularly the case with early iron and steel artifacts, as practically all of the information regarding how the object was made and what it is composed of can only be determined by microscopic examination of a cut and polished internal section. This paper presents the results of pilot experiments to develop a new, completely non-invasive method of microstructural and compositional analysis of archaeological iron, using the ISIS neutron diffraction facility at the Rutherford-Appleton Laboratory, Chilton, UK.

contents were derived by calculation from the quantity of Fe3C detected. Carbon contents calculated from the analysis of the modern steel standards were consistently slightly lower than those estimated by metallography. The phases identified in the standards were ferrite and Fe3C. In the archaeological objects, ferrite and Fe3C were identified, along with outer corrosion layers, mainly Fe3O4 and FeOOH. The method again slightly underestimated carbon contents. Results Around 30 artifacts were analyzed over the course of five days. None of the objects retained radiation for more than four hours; all were cleared to be returned to the museums immediately after the experiments. One of the Rhenen seaxes was shown to have a 2 cm wide highcarbon steel back, welded on to a 2 cm wide ferritic iron blade; diffraction measurements were taken along the length of the blade, from hilt to tip, to establish whether any traces of carburization remained on the cutting edge. High resolution diffraction volume scans of 2 x 2 x 10 mm, and 4 x 4 x 20 mm were made across the breadth of the Rhenen spearheads, from edge to edge. Texture goniometry of one of the Heeten artefacts demonstrated extreme cold-working of phosphoric iron, conclusively disproving the widely held view that it is not possible to cold-work phosphoric iron.

Introduction The understandable reluctance of curators to allow samples to be cut from metal artifacts has limited the amount of technological information that can potentially be extracted from the objects. This is particularly the case with early iron and steel artifacts, as practically all of the information regarding how the object was made and what it is composed of can only be determined by microscopic examination of a cut and polished internal section. In order to explore the potential for using the ISIS neutron diffraction facility at the RutherfordAppleton Laboratory in Oxfordshire, UK, to conduct non-invasive microstructural and compositional analysis of archaeological iron, a series of pilot experiments were run.

Conclusions Neutron diffraction analysis was shown to be a viable, totally non-invasive method of characterizing ancient iron artifacts. A high throughput of samples is possible compared to, for example, metallographic sample preparation time. Although the method involves nuclear particles, it does not leave the objects radioactive. Neutrons are more penetrating than X-rays, and thus provide a more effective means of assessing preserved metal under corrosion layers than X-ray diffraction. However, due to the extreme microstructural heterogeneity of archaeological iron artifacts, further work is necessary to optimize the resolution of the method. A combination of neutron methods, e.g., diffraction, tomography, and chemical analysis by prompt-gamma activation analysis, could in future provide much more comprehensive non-destructive characterization of iron objects.

Samples Neutron diffraction analyses were conducted on three sets of material: a series of modern carbon steel standards with carbon contents of 0.1wt% C to 2.1wt% C; archaeological iron and steel artifacts of known microstructure and composition from the Roman–Iron Age site of Heeten (4th/5th centuries AD) in the Netherlands; and previously unanalyzed Merovingian iron and steel spearheads and single-edged swords, known as ‘seaxes,’ from the site of Rhenen (6th/7th centuries AD) in the Netherlands. The Heeten artifacts are well preserved; they were excavated in the early 1990s and had one episode of conservation treatment, when bulky corrosion was mechanically removed. The Rhenen artifacts, excavated in the 1950s, are also well preserved. They were subjected to several campaigns of conservation over the years, and extensively restored.

Acknowledgements The author would like to acknowledge the help and support received from her co-investigators: Winfried Kockelmann, Rutherford-Appleton Laboratory, Chilton, Oxfordshire, UK; Matthijs van Nie, EGA Archaeological Consultants, Bradford, Yorkshire, UK; Dirk Visser, Rutherford-Appleton Laboratory; and Javier Santisteban, Rutherford-Appleton Laboratory.

Method Entire artifacts were placed on the sample stage and analyzed in air. No sample preparation was necessary. Diffraction measurements were initially made at a volume of 10 x 10 x 10 mm into the metal. Average crystallographic phase fractions were determined by Rietveld analysis, giving d-spacing values. Carbon

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THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Address Isis Neutron Source Rutherford Laboratory Hartwell Science and Innovation Campus Didcot OX11 0QX UK

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A CHANGE IN PHILOSOPHY FOR THE CARE OF ARCHAEOLOGICAL COLLECTIONS? Hedley Swain Abstract A review of the philosophy behind archaeological collection management and curation is followed by a summary of current progress and best practice. This asks why there is a need to keep all archaeological material when collections are under-used and under-resourced. The situation in London is described where the creation of the London Archaeological Archive and Research Centre in 2002 has hopefully set a model of best practice. Finally a discussion of how collections might be curated in the future is presented.

records and how they are managed. There is no place for objects in this model. So for some, even if the term archaeological archive is used, it will only refer to the written records associated with an excavation or piece of fieldwork, not the finds. This distinction is sometimes made real by the way fieldwork records and finds are stored and managed separately. In both Scotland and Wales it is normal practice for the records from excavations to be ‘archived’ and kept by the respective Royal Commissions (RCAHMS, the Royal Commission for Ancient and Historic Monuments Scotland, and RCAHMW, The Royal Commission for Ancient and Historic Monuments Wales) while the finds from excavations go to regional or national museums.

Introduction ‘The characteristic smell of the archaeological store, compounded of embalmed oddments, massed ceramic and preserved wood, faintly spicy and faintly dusty, is the sweet stench of mummification, and curators become cemetery-haunting necrophiliacs compelled by a dubious romantic impulse to arrest time and decay’ (Pearce 1997: 51).

This practice of separating finds from records is not unusual elsewhere, and has often been the practice in the past. However, in England the concept of the unified archive, that is, all the products of fieldwork, records and objects being curated together, has taken hold and is strongly argued for (for example, Merriman and Swain 1999).

‘It could certainly be said, from the archaeological point of view, that to deposit an object in a museum is a lesser evil rather than an aim to be pursued for its own sake’ (Charles-Picard 1972).

Other terms are used. These include archaeological assemblages, site assemblages, site records, site collections, and more. In North America the term archaeological collection often has the same meaning as an archive in the UK and this is the term Terry Childs and Lynne Sullivan use in their recent book (Childs and Sullivan 2003).

‘The massed weight of archaeological storage boxes demonstrate daily the success of archaeological investigators in convincing museum staff of their claims for institutional immortality’ (Pearce 1997: 48). Susan Pearce, the grand matriarch of British museum archaeology, is certainly not someone to avoid a controversial statement, or some poetic musings. I do not know Charles-Picard but I think it is fair to say that he is of the old school of macho French field archaeologists. In this paper I wish to discuss whether curators, conservators, and collections managers are indeed necrophiliacs; whether storage in a museum is indeed a lesser evil; and whether archaeologists are just seeking institutional immortality.

The great advantage of the term archaeological archive is that it can be used to describe an entity that makes sense in archaeological terms. What makes archaeological evidence unique is the importance placed on context, relationship, and assemblage. And an archive makes sense of this by putting the objects or finds with the records of their context, and the indexes that explain their relationships. So, as discussed here, an archaeological archive is all the finds, records, and associated evidence from a particular archaeological intervention, normally an excavation. Personally, I believe the right and proper home for such archives is in a museum. And in England this is where they are supposed to spend eternity.

After summarizing the basic philosophies behind archaeological collections curation I will describe where I feel major progress has been made in this field, and where progress is still needed. I will then briefly summarize approaches to archaeological collections management in London before discussing priorities for the future.

Similarly, the term ‘repository’ is not normally used in the UK. Probably the main reason for this is that it is normally expected that all archaeological archives, or collections, will end up in museums. So there is no need for a word to explain a collection outside a museum. In the UK there is more discussion about ‘resource centers’ or ‘research centers’ that might or might not be attached to a museum. I understand that in the United States, repositories are where archives (or collections) end up, and these may or may not be attached to a museum.

Nomenclature Some explanation of terms is needed. The term archaeological archive, in the sense I normally use it, is not commonly used outside the United Kingdom, and even there, some are uncomfortable with it. Traditionally, and for many currently, the term archive has very particular associations with documentary 145

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS comes out of the ground, it is in the hands of others, the cultural resource managers, the developers, the state archaeologists. So theoretically, museums are making a commitment to the endless curation of an endless supply of archaeological material.

Finally, in the UK, ‘cultural resource management’ (CRM) is used to describe, in a very loose way, the whole archaeological management system (for example, Hunter and Ralston 1993); whereas in the U.S., it is used specifically to describe the system whereby archaeological contractors do work to mitigate the damage done by development. In the UK, this tends to be called ‘contract archaeology’ or ‘development-led archaeology’.

And yet even though it is essential to preserve and record everything, and then keep everything, the majority of the archaeological profession does not seem to be prepared to find the resources for proper curation, or to make use of this resource by continual re-examination and research. The archives from key sites do get re-worked and re-analyzed. In Britain the Mesolithic hunting camp at Star Carr in Yorkshire (Clark 1954) is a good example of this. But this is only a tiny drop in the ocean compared with the vast amount of material that is not being actively worked on.

So in this paper, archaeological archives and collections are the same thing; as are repositories, resource centers, research centers, and museums. And CRM can be used for those archaeological practices that create the collections and control this process. The background Terry Childs and Lynne Sullivan, in their recent book on curating archaeological collections, describe a ‘crisis’ (Childs and Sullivan 2003: 1) that derives from archaeologists not seeing the archiving of archaeological collections as anything other than an afterthought. This philosophical problem contributes to a practical problem of resources. Although the CRM world seems awash with money to dig up new archaeology in advance of redevelopment, there does not seem to be enough to curate the material already dug up, or prepare new material for long-term curation. Perhaps even more worryingly, the archaeological community as a whole does not seem to value these collections, or be using them for research or other activities. This perception is similar in the UK, and indeed just about everywhere I have been.

Successes Within this model of keeping objective records of excavations as archives and curating them for posterity, much progress has been made in recent years. Until relatively recently, even if archaeologists had wanted to access collections, they would not have been able to because of poor curation and collections management. The huge increase in archaeological material that has come from the CRM system has forced curators to find new ways of managing collections. The importance of documentation has been recognized. If an institution does not know what materials it holds, or where those materials are, it may as well not have the collections at all. Archaeologists and museums have taken advantage of the digital revolution to document their collections and are beginning to use the Internet to make these resources available globally.

Why should this be so? Why do archaeologists not value these collections or put enough resources into their care? It seems to me that archaeology and the preservation of archaeological collections are based on two premises. The first is that archaeological excavation is an unrepeatable experiment and that there is a duty to preserve the results of this experiment ‘by record’. The aim is to create an objective record of what has been excavated that can be continually re-examined and reinterpreted for infinity. The record acts in-proxy for the site that has been destroyed.

Museums and repositories have also developed methodologies that allow them to conserve, stabilize, and care for the large and complex collections they are increasingly being asked to curate. A key component of this efficient, professional, and, by necessity, economic management of repositories is the use of condition surveys. An increasingly sophisticated tool kit of storage methods, building environments, and active management are available to ensure, at the least, that collections do not deteriorate and can be accessible for those who would use them. Whether those resources are in place and whether they are used is another matter.

This model was born at the turn of the 20th century by people such as Pitt Rivers and has remained a basic tenet of archaeological practice ever since. But in a postmodern age, most would now accept that there is no such thing as objectivity or absolute truths that can be revealed by excavation and the re-examination of records. Nevertheless, archaeologists cling on to the ‘preservation by record’ orthodoxy.

The availability of curation and conservation expertise is also acknowledged within the sector. The contribution conservators can make to the analysis and research into objects has been demonstrated and now often forms a key component of archaeological research projects. Of course this is also a matter of resources. It is the case that there are too few curators and too few conservators spread too thinly. In the UK one strong argument for resource centers is to create the necessary critical mass and economies of scale to provide adequate conservation and curatorial care that is currently spread too thinly or concentrated in particular locations.

The second premise is that museums have a duty to preserve their collections forever. Curators must not let collections deteriorate and they must not dispose of them. For archaeology this is made more difficult because museums do not choose what they are expected to collect—they cannot decide how much archaeology

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HEDLEY SWAIN: A CHANGE IN PHILOSOPHY FOR THE CARE OF ARCHAEOLOGICAL COLLECTIONS? In Britain, Prime Minister Thatcher believed in something called the ‘trickle down’ effect for wealth. The idea was if you made the rich richer, eventually they would spend some of their money on the poor; it would trickle down to them. It seems to me that most archaeological effort is based on the same premise. If archaeologists keep the collections, a few researchers will look at them, and some of their work will eventually trickle down into school textbooks and museum displays. I have occasionally come across archaeologists who do not even need this incentive. They are content that because it is old and part of our heritage it should be kept safe, even if no one ever comes to look at it.

In this regard the sector has begun to think and act strategically, although getting buy-in from all is sometimes hard. For too many years those who care about collections and had responsibility for them have failed to argue a case within a wider arena that includes the whole profession. In the UK the Archaeological Archives Forum (AAF) is coordinating strategic and policy thinking into archive management, as described in Kathy Perrin’s paper (this volume). The profession is now also at least thinking about disaster management, and in 2005 of all years, the need for this has been brought home to all. In the UK, one of the first pieces of work undertaken by the AAF was to produce guidance on how archaeologists should protect records against disasters (Aitchison 2004).

I am afraid neither model is good enough for me. I know from experience that normal people love to touch and see real things, ideally not behind glass cases, and do have a real and immediate interest in their past and in the place they live. Publics and communities come in many shapes and forms, and archaeologists should be seeking to engage with them at every opportunity. Repositories should not be there just to look after old things, or just for professional archaeologists. They should be there for all the many different publics, and archaeologists must work hard to unlock their value to these groups. When this has been done it may be that there is a realization that some of our irreplaceable heritage is actually not very interesting to anyone. This inevitably leads to the observation that there may not be a need to keep it all.

It is now also recognized that there is the need for standards and guidance in creating records, collections, and archives. This includes the need for standardization in methods and recording and packaging. The progress that has been made is patchy, and has been hard and often frustrating work. There are still many circumstances where finances or lack of training, infrastructure, or critical mass prevent progress and best practice. However, on the whole, most major collections are now well cared for, sustainable, and accessible. It is recognized that resources are needed to achieve this.

Is there still a strong argument for keeping all the archaeological collections that exist and all the material that comes from new excavations? The question of disposal goes back to those two gospels of archaeology and museums discussed above: preservation by record and keeping things forever.

But it would appear that the archaeology profession still undervalues collections, conservation, and documentation. This is odd when archaeology was founded on and developed out of its collections. In the 19th century, collections were everything and sites unimportant. It now seems that for many the opposite is true. It was field archaeologists who developed the notion of preservation by record; it is a shame that it is they who, while still clinging on to this ethos, are dismissive about using the record.

This is a subject that is now being addressed in the UK for museum collections in general, and a debate has begun about archaeological material specifically. The debate is centered on the fact that we are spending a lot of money curating many museum collections that are hardly ever used. If the profession can for a moment put aside the preservation by record ethos—that we have to keep things, because they have been excavated—just what is the evidence that material is worth keeping?

Challenges In the struggle to improve standards it is sometimes easy to forget why we are preserving collections in the first place. Why are archaeologists objectively recording collections and aiming to keep them forever? Why are the repository and archive managers trying to make collections better managed and better resourced?

Some categories of archaeological material are highly researched and have the potential to reveal new information in the future as scientific techniques improve and our knowledge base increases. Ironically for the US in the post-NAGPRA world, human remains is one such category (NAGPRA = Native American Graves Protection and Repatriation Act). It is also the case that the archives from major sites; type-series; and important objects will always be in demand. I hope that strong assemblages from good contexts on representative sites will also always have an important part to play in research, display, and education.

These are important questions to ask. I personally believe that archaeology is primarily about its contribution to wider society and should always be referenced to that. I think it is unlikely that archaeological research will reverse global warming, help find a cure for cancer, or even teach the United States and Britain not to invade other people’s countries. However, I think as a general rule people are inquisitive and want to know about the world around them and are slightly better people and better citizens if they do. I do not believe the past should be preserved just because it is the past. But I do believe that the more textured life is, the richer it is.

However, unstratified material; uncontextualised material; residual fragmentary material; mass, mundane 147

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Museum’s recurrent costs and short-term project funding (currently supporting two of the staff). No conservators are currently attached full-time to the LAARC but the Museum’s well staffed and experienced conservation and collections care department support it and were involved in its creation.

and repetitive bulk finds; and very small assemblages from evaluations have a very limited research potential. Releasing this material from archives allows a more imaginative use for teaching and other pursuits. I am not suggesting wide-scale disposal of archaeological finds. I am suggesting a different approach to why we keep material.

The core staff for the LAARC is adequate for its day-today management and curation. Extra project funds are sought to undertake specific enhancement and research projects. These currently include a major project funded by the Wellcome Trust to produce an on-line database of 5,000 of the 17,000 human skeletons held in the archive.

The LAARC Many of the challenges of long-term curation of archaeological curation have been addressed in London in the last few years. An attempt has been made to embrace the need for an easily accessible and sustainable home for the material from past London excavations.

The London archive is by far the largest in Britain. It currently includes about 150,000 individual boxes of finds stored on 10,000 m of shelving, and includes finds and records from about 5,200 individual excavations from throughout Greater London. And of course this figure is growing every year (by on average 300 new projects). Therefore about 20 years’ worth of expansion space has been built into the plans. This will be achieved partly through current spare space but also by the rationalization of existing material. For example, a program is recording and then discarding some assemblages of mundane and repetitive ceramic building materials. These materials are from past excavations and would not have been retained under modern excavation methodologies.

Since its foundation in 1976 the Museum of London has acted as the traditional home for archaeology in the capital. The Museum’s field units, in their different incarnations, have carried out the vast majority of excavation in Greater London. The Museum’s main galleries tell London’s story from prehistory to the 20th century and draw heavily on archaeology, as have some of its recent temporary exhibitions such as London Bodies, which used human skeletons to show how the appearance of Londoners changed through the ages, and High Street Londinium, which focused on how excavations helped to reconstruct the appearance of Roman Londinium. Behind the scenes the Museum also cares for the archives from excavations in Greater London. It has long been realized that this material offers both great challenges in terms of its sheer quantity and an incredible untapped resource for research (in effect everything anyone knows about prehistoric, Roman, and Saxon London, and much of what is known about medieval and later London is held in the finds and records within the archive). In the creation of the London Archaeological Archive and Research Centre (LAARC) the Museum has tried to meet these challenges.

The Museum has prepared rigorous standards for the preparation of new archives resulting from excavations and expects the archives from all excavations in Greater London to be deposited in the LAARC (the standards are downloadable from the Museum’s Web site). A key part of the standards deals with digital records and archives. It is realized that more and more primary archaeological data is generated and held in digital form, and this will increase in the future. One of the two records officers at the LAARC specializes in digital information and is working hard to ensure the material that comes to the LAARC can be easily read, managed, and when necessary, migrated on; that we can make this data available to researchers; and that it is compatible with digital data from other excavation archives. This is a daunting challenge, not least because of the vast amount of digital data already held that was generated over the last 30 years as computer use in archaeology evolved. The Museum of London can probably just about manage; many smaller museums and repositories will not.

The LAARC was opened in February 2002. It is housed in the Museum of London’s Mortimer Wheeler House resource centre, about two miles from the main Museum building and its galleries. LAARC shares the building with the offices of the Museum’s archaeology service and much of the Museum’s social and working history collections. A grant from the Heritage Lottery Fund (the UK’s national lottery) provided about 50% of the funding to create the LAARC. Other funds came from central government, The Getty Grant Program, and many other organizations, archaeological societies, and individuals. Two new large storage areas have been created, as well as a visitor centre and two study rooms. State-of-the-art roller storage has been installed and a computerized index and access system (the latter available over the Web) have been developed. The LAARC project, which included not only building and equipping the new spaces, but also designing the computer systems and undertaking a minimum standards program, cost about £2.5 million. Costs for the sixperson team who manage the LAARC is found from the

It has taken a while for the twenty or so archaeological contractors that regularly operate in London to become accustomed to this new disciplined approach, but the will does seem to be there and material is now being deposited at an increased rate (although currently, more new sites in London are begun than are deposited, and under English archaeological systems there is no legal compunction for deposition at the LAARC).

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HEDLEY SWAIN: A CHANGE IN PHILOSOPHY FOR THE CARE OF ARCHAEOLOGICAL COLLECTIONS? LAARC and last summer it acted as the base for a local community excavation. But its main value is as a foundation for other activities. The High Street Londinium and London Bodies exhibitions would have been impossible without the Museum’s archive. The sorting and rationalization of material in the archive has also made possible the Museum’s Roman Boxes for Schools scheme whereby unstratified material has been turned into teaching collections (Hall and Swain 2000). Such material was also used in The Dig, a re-created excavation using real artifacts which was the Museum’s summer family event in 2001 (Martin 2002).

Meanwhile the Museum has also turned its attention to the material already in its care. This has been generated over about 100 years by many different archaeologists working for many different organizations. Material is not compatible and often not easily accessible. A huge effort is being made to bring all this material up to an acceptable level of care and accessibility, not only for its long-term well being but also to encourage research. A major element of this work is using the Museum’s established condition reporting system. The process was greatly helped by the Getty’s Minimum Standards program, which funded a team of three staff including a conservator to sort through, re-package, and document the condition of about 30% of the finds in the archive. This work was supported by a team of volunteers and eventually became a community project (Langfeldt and Ganiaris, this volume).

So far, by my own very harsh standards I would consider the LAARC a qualified success. I am still concerned that the LAARC is not being used as much as I would wish; and that it is a very expensive undertaking when directly compared with the number of its users.

Research has been spearheaded by the publication of a London archaeological research framework (McAdam et al. 2002) and a series of partnerships with London’s archaeologists and universities. The international research potential of material held at the LAARC is also being recognized. The Museum already has formal partnerships in place with La Trobe University in Melbourne, Australia to study 18th- and 19th-century assemblages and with Pennsylvania State University, USA, which is studying DNA from some of the skeletons held in the archive.

Conclusions So where is the profession at present in the process of coming to terms with the archive challenge? If nothing else, the language for this subject seems to be heading in the right direction. Pete Hinton, director of the British Institute of Field Archaeologists, has famously referred to archives as equivalent to low-level nuclear waste, and I (Swain 2004) once made an analogy with WMD, Weapons of Mass Destruction: lots of people talk about them but when it comes to it they are quite hard to find. At a recent UK conference session there was talk of ‘special needs’ and ‘orphans’. This is far more touchyfeely; who knows, we may eventually get to love these products of our endeavors.

Of huge importance here is the Archive Archaeology project currently being funded by the Higher Education Funding Authority in England (HEFCE). This three-year project is aimed at persuading English universities to include archive study in its undergraduate programs. The LAARC is working on one part of the project with the Institute of Archaeology, University College London. All undergraduates will visit the LAARC and undertake work placements in it. The hope is that we can slightly shift the excavation-dominated road to a researchoriented one.

Personally, I do feel we need some serious therapy in order to come to a new level of understanding with archives. For a start, I suggest we free ourselves from the past and begin again from the premise that there is no imperative to preserve by record forever. Instead let’s think about current needs and demands. Archaeological research, outreach, and interpretation do need the results of past work; and some of what is excavated will be of value for many years to come. Also such material will need to be well managed, documented, and accessible.

Another key part of the London archaeological community is its local societies, and again the Museum is working with these groups to encourage research and use of the LAARC. Several societies were actively involved in the planning of the LAARC and have donated funds for its creation. It is hoped that society projects either researching London’s past or helping with collections management in the LAARC will allow local society members to feel actively involved in London’s archaeology—something that has been very difficult in the last 10 years as more and more archaeology has been funded commercially by developers. Under another initiative, the LAARC is hosting a Central London Young Archaeologists Club for children and teenagers.

Archaeologists should seek to create sustainable archaeological resource and research centers where trained and experienced archaeological curators, conservators, and researchers (and in some cases individuals could be all three) care for environmentally stable, open-access repositories. These centers should keep the best examples of archaeological material for a particular region and a representative sample of all of the archaeology from a region. These will be kept there not just because they have been dug up, but because they are valued and in demand for research, teaching, and enjoyment.

The LAARC is not an alternative to the Museum’s galleries and it is fully appreciated that archives may not be the best way of introducing the general public to archaeology. There are public weekend events at the

Curators and conservators should be working with those involved in archaeological resource management, in all of its guises, to ensure archaeology is excavated, sampled, recorded, and analyzed in a way that will make 149

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Clark, J.G.D. 1954. Excavations at Cambridge: Cambridge University Press.

curation straightforward and maximize future access. To do this, comprehensive, practical guidance and standards are necessary, and need to be endorsed by the whole profession and be built into contracts.

Hunter, J., and I. Ralston. 1993. Archaeological Resource Management in the UK. Bath, UK: Alan Sutton Publishing.

To this end, documentation, digitization, and access methodologies are essential. Repository managers must know what they have, where it is, and what state it is in. And they must give this information to all who might need it.

Martin, D. 2002. Great excavations. Museums Practice 19 (7): 21-32. McAdam, E., T. Nixon, H. Swain, and R. Tomber, eds. 2002. A Research Framework for London Archaeology 2002. London: Museum of London.

And in Europe, if not yet in the US, there is a need for a discreet and secure very large hole. It can be given a complicated professional sounding name like the Archaeological Long-Term Randomly Stored Heritage Location, into which is put all the stuff that is dug up and recorded but it is decided is not needed for future research, or for any other useful purpose.

Merriman, N., and H. Swain. 1999. Archaeological archives: serving the public interest? European Journal of Archaeology 2 (2): 249-267. Pearce, S. 1997. Archaeology as collection. The Museum Archaeologist 22: 6-12.

The model outlined above has three major philosophical building blocks: Care of collections so they can be used, not just because they are there;

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Sustainability;

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Archaeology as a holistic process rather than a compartmentalized, linear one.

Carr.

Hall, J., and H. Swain. 2000. Roman boxes for London’s schools: an outreach service by the Museum of London. In Archaeological Displays and the Public, ed. P.M. McManus. London: Archetype Publications.

Repository managers must also seek to work with all their communities. These include fellow professionals, universities, schools, amateur archaeologists, and the communities whose past is being excavated and managed.

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Star

Swain, H. 2004. The Archaeological Archives Forum. The Archaeologist 53: 31-32. Biography Hedley Swain is head of Early London History and Collections at the Museum of London. He is currently chair of the British Society of Museum Archaeologists and Archaeological Archive Forum. He is an honorary lecturer at the Institute of Archaeology, University College London. He has lectured and published widely on archaeological collections.

The first of these is within our power. The second is a practical consideration. The third, depressingly, I still see little evidence for. However, just recognizing it as a problem is a start. In the meantime, professional, dedicated curators, conservators, and collections managers will continue to preserve our collective heritage until such time as we can unlock its wealth.

Address Head of Early London History and Collections Museum of London London Wall London, EC2Y 5HN UK

So to conclude: no, curators, conservators, and collections managers are not necrophiliacs; storage in a museum is certainly not a lesser evil; but there may be a few archaeologists out there seeking institutional immortality. Bibliography Aitchison, K. 2004. Disaster Management Planning for Archaeological Archives. IFA Paper No. 8. London: Institute of Field Archaeologists. Charles-Picard, G. 1972. Larousse Encyclopaedia of Archaeology. New York: G.P. Putnam’s Sons. Childs, S.T., and L. Sullivan. 2003. Curating Archaeological Collections. Walnut Creek, CA: Altamira Press. 150

THE WORK OF THE ARCHAEOLOGICAL ARCHIVES FORUM IN THE UNITED KINGDOM Kathy Perrin Abstract Ensuring that archaeological archives are an accessible, useful, and well-used resource is a priority for the archaeological community as a whole. Archaeologists acknowledge the importance of recording and archiving the results of their work to the highest standards. However, it can be a struggle to find the resources to properly care for archaeological finds and records, and perhaps more importantly to provide good access to this material and use it for meaningful research. In the United Kingdom (UK) the Archaeological Archives Forum is working hard to build an infrastructure which will ensure that archaeological finds and records are properly cared for, documented, and made fully accessible. It is important to note that in the UK we have recognized that success will only be achieved if all sectors involved in the archaeological process work together; therefore, the Forum is comprised of representatives of all the major players in the UK Heritage sector. This paper briefly outlines the main issues and the progress the Archaeological Archives Forum has made since its inception in 2002.

to build this infrastructure, thus ensuring that archaeological finds and records are properly cared for, documented, and made fully accessible. It is important to note that in the UK we have recognized that success will only be achieved if all sectors involved in the archaeological process work together. The Archaeological Archives Forum is working on three major challenges: issues regarding the deposition of archives in a suitable repository, the means of providing full and interactive access to archives, and ensuring that documentation and finding aids properly facilitate the researcher. Historical background England’s problems developed over time as archaeological work left the province of the small independent researcher or university department and became an industry in its own right. A quick foray through history tells us that on the whole, archaeological work had been carried out on a small scale until the 1970s and it tended to lie in the province of universities or independent researchers. In the 1970s, burgeoning town development, including the creation of a number of new towns, combined with the advent of rescue archaeology to create a huge increase in excavation. Archaeological units were formed in most areas and large post-excavation backlogs built up as digging tended to continue all year round. This situation was exacerbated in the 1980s when a government scheme to put unemployed people to work brought large numbers of mostly inexperienced extra staff into archaeological units with a concurrent increase in output but often at the expense of quality and post-excavation programs.

Introduction Archaeologists acknowledge the importance of recording and archiving the results of their work to the highest standards. However, sometimes it can be a struggle to find the resources to properly care for archaeological finds and records and, perhaps more importantly, to provide access to this material and ensure its use for meaningful research. The advent of the digital age has resulted in many institutions finding new and innovative ways of getting the results of archaeology out to the world. These range from individual specialist group websites to the much wider vision of a project like AREA (ARchives of European Archaeology), whose aim is to create new possibilities for the promotion and preservation of European archaeology archives. Along with this development are other exciting changes in the way that the physical remains of archaeology are being made far more accessible to both existing and new audiences, such as at the London Archaeological Archive and Resource Centre, the LAARC. This new development aims to collect and care for, provide access to, and encourage research into the finds and records of archaeological work in London. Also, within England, information about archaeology is about to become an integral part of information about the whole heritage environment through the development of heritage environment records.

In the 1990s a change in government policy saw the concept of ‘the polluter pays’ applied to building development, and for the first time archaeological units had to compete for work which was now funded by private companies. Small, rapid evaluations and an explosion in grey literature combined with a paring of costs and even more pressure to reduce archiving procedures. How has all this affected the archives? On a simplistic level it can be explained as follows: In the 1970s and 1980s most archaeologists did not have much time to consider the archives they were creating—attention was focused on excavation, recording, and publication. Such huge amounts of activity meant that large archive holdings were building up in unit stores and offices. In the 1990s, commercial practice meant that increased pressure of work due to contractual deadlines left the backlogs to be done only ‘as and when’, and the archives from later commercial development work often fell victim to inadequate monitoring by overworked county archaeologists. As a result, large quantities of archives,

The difficulty is that such forward-thinking initiatives can be hampered by a lack of basic infrastructure to support access to the finds and information. The Archaeological Archives Forum, a consortium of all the major archaeological bodies in the UK, is working hard 151

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS often inadequately prepared and stored, were looking for homes in museums equally ill-prepared to receive them for reasons detailed later.

potential audience—schoolchildren, academics, the general public? •

Archaeologists in England have been aware of these issues for some years. A study carried out in 1998 on behalf of English Heritage (EH) and the Museums and Galleries Commission (MGC) by Hedley Swain et al. concluded that a number of initiatives were needed, including: • • • • •

National coverage in museum collecting areas A review of the EH storage grant scheme Guidance on selection and disposal of archaeological materials A study of the physical condition of major archives held by contractors and the cost and feasibility of their transfer to museums A review of the nature and sustainability of digital data.

Major concerns The term archiving is used quite freely to describe the process of depositing the product of archaeological research in a public repository. In fact, it is a poor term for a practice that can vary as wildly as just throwing everything in a box and giving it to the museum, to taking immense care that everything is ordered, indexed, conserved, and packaged appropriately. The following can be identified as major concerns in archiving practices:

EH proposed to take these recommendations forward in partnership with other bodies, especially the MGC. However, in the following period, rapid changes overtook EH and MGC and it took a further three years before any real action could be initiated. In order to begin work with up-to-date information, EH carried out a rapid scoping survey during 2001 and published Archaeological Archives: Documentation, Access and Deposition: A Way Forward in 2002. This document recommended a plan of action which aimed to tackle the most pressing problems, but argued that success would only be achieved if all sectors involved in the archaeological process were to work together. As a result, in March 2002, the Archaeological Archives Forum was formed, and six months later it became a nationally representative body when Northern Ireland, Scotland, and Wales joined as members.

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Common standards. There are no commonly held standards for the selection, preparation, and deposition of archaeological archives. Nor is there a commonly held understanding of the differing roles and responsibilities of those dealing with the archive within the heritage sector.

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Selection processes. There is a widespread reluctance to critically assess what should be kept and what can be discarded. The common approach is to collect and keep all materials on the hope that future generations will be better able to understand it. Experience argues against this theory—current trends demonstrate that archives are seldom revisited, and hard-pressed local authorities pick up on this information when taking cost-cutting decisions. It is important to become proactive in taking decisions about retention and to be able to justify this decision-making process with sound research criteria. The danger is that if archaeologists do not address this issue, then in the UK, decisions will be made for us on the unacceptable basis of cost. This is not a fantasy scenario—bulging stores and massive quantities of bulk materials with no identifiable repository are all too common in most of the UK.

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Temporary storage. Storage of sensitive archive material can become a problem in the temporary stores available to most archaeological practices. This includes documentary archives; for example, photographic images require good storage conditions or they can fade or develop mould or foxing. Currently we do not have recognized standards for these stores and yet archives can remain in such temporary situations for many years. Some of them are truly awful; it is not unknown to have archives stored in hot, humid boiler rooms, wet

The current situation Three major archives challenges were identified: documentation, access, and deposition. •

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Deposition. Problems relating to deposition include: the scale of the material generated by fieldwork projects, its storage and curation, and whether discard policies exist. An increasing number of museums have difficulty in housing new and especially large archaeological collections and some stores are full or close to capacity.

Documentation. This is the information provided with an archive to allow others to use it easily. This can be as simple as clear labeling on boxes and paperwork, or more complex, such as the metadata provided from digital files. The preparation for a clear and usable archive must begin before the archaeological team hits the ground, and not be just a process that is tacked on at the end of the project. Access. We do not often think of an archive as a resource to be utilized in the same way that we do the publication, but in fact the same amount of care and attention should be expended on the archive so that it can be well used and accessible. Questions to be considered include: How easy is it to find and use the resources in archives? How many of the potential audience are able to reach it? Who are the

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KATHY PERRIN: THE WORK OF THE ARCHAEOLOGICAL ARCHIVES FORUM IN THE UNITED KINGDOM cellars, and in one spectacular case, broken down chicken sheds with brambles growing through the roof. •

How do we change things for the better? There have been many attempts to tackle some of these issues, but too often they have not succeeded because they have been done in isolation. For example, standards produced by the museum community alone may not be taken up by the archaeologists because archaeologists do not think they apply to them. It is important, therefore, to ensure that all the differing groups working within the field of archaeology are on board with the solutions proposed.

Access. We need to make the archives more accessible and capable of re-use. This is a complicated issue, with problems such as providing a knowledgeable curator, documenting archives clearly enough that future researchers can find answers easily, and making good use of the Internet in order to reach new audiences.

Under the banner of a national Archaeological Archives Forum we have brought together representatives from across the heritage sector, including our national colleagues in Scotland, Ireland, and Wales, in order to deal with issues collectively. Working together means more weight attached to initiatives, more available resources, better results enjoyed by a larger group, and solutions that are taken more seriously by government. Some of the issues we are currently tackling include:

Where do archives go? The traditional storage arrangement within most of the UK is to deposit archaeological archives in a local museum. Unfortunately, this seemingly straightforward solution poses a number of problems. The museums in question are often old establishments in inner cities with limited storage or growth space. These traditional museums are designed, on the whole, to house displayable objects, not boxes and boxes of bulk material such as animal bone and bits of broken pottery. Most museums in England have difficulty housing archaeological archives and an increasing number are turning them away.

Disaster management planning Most archaeological organizations operate within a health and safety code of practice that minimizes the risk to staff as much as possible. However, most do not apply the same principles to the business side of their work, and as a result the irreplaceable information on which their livelihood depends is put at risk from natural events (such as fire or flood) and manmade events (such as robbery or terrorist activity). The Forum has published guidance on disaster management planning for archaeological archives (Aitchison 2004).

Museums are increasingly stretched for resources and many have lost the staff with the archaeological expertise to utilize the archives. This in turn means only limited reuse of the archive is possible in most cases. In England, archaeological material and its documentary archive are traditionally deposited together, a situation which does not happen with other sorts of collections. Documentary archives are normally the province of the local record office which has specialist staff skilled in its conservation. Caring for the documentary archive associated with archaeological archives puts an extra burden on museum staff and resources.

Standards for post-excavation archiving processes We need commonly held transparent standards for the whole discipline, from the person writing the archaeological brief to the curator accepting the archive at the end of the process. Each must know and understand what others are doing, and why and when they fit into the picture. It is recognized that two major pieces of guidance are needed most urgently.

The move away from traditional paper and photographic records towards ‘born digital’ records and digital records requires specialist curation not always found in museums. Therefore, if an archaeological practice deposits a digital archive in a museum, it may mean that a disc is put on a shelf to gather dust. Often the museum does not have the means to store, migrate, and provide access to the data present on the disc. Happily, we are now moving toward a situation where specialist repositories will curate and provide access to digital records. The Archaeology Data Service is one such example in the UK and the National Archives are beginning a project which hopes to provide regional solutions. However, these are early days for a situation which needs urgent solutions, and not solely for archaeological data.

A national framework for selection is needed in which regional, local, and site- or project-specific policies can be developed. It is important that the issue of what is retrieved in the field and later selected for retention is justified against sound policies at each stage of the process. This issue has been overlooked for too long, leading to an almost critical overload of archaeological material which, because it cannot be weighed against sound selection criteria, is vulnerable to disposal by hard-pressed local authorities. Another area where standards are most urgently required is in the temporary storage of archaeological archives. It is vital that sensitive archaeological material and records are not allowed to degrade due to inadequate storage facilities at any time. Museums are well regulated, but this is not the case for storage facilities in most archaeological practices. A recent survey demonstrated that nearly all units had dedicated stores for finds but that almost none operated any form of environmental

In England, there are few consistent charging, collecting, or accession standards in place for museums, a fact which causes real problems for many archaeological practices who have to produce archives to many differing standards. 153

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS will provide not only adequate regulated storage space but also access to curatorial support and advice, archaeological expertise, conservation support, and massive opportunities for training, research, teaching, and outreach including a presence on the Internet.

controls. In the case of documentary storage, the majority of units maintained these in standard offices, with all the inherent problems of fluctuating heat, light, and humidity. Standards for the temporary care of archaeological archives will be included within the standards document.

We are currently engaged in dialogue with English Heritage, the Museums, Libraries and Archives Council and the Heritage Lottery Fund about a strategy and funding policy for the development of a network of archaeological resource centers. In the meantime our current initiatives are putting the building blocks in place in order for these centers to operate smoothly.

The national standards for post-excavation archiving processing are well under way. Work on mapping existing standards has been completed and work on drafting an overall common standards document began this autumn. The published standards document will be badged with the Archaeological Archives Forum logo in order that it is accepted on a multi-discipline basis.

Conclusion The formation of the Archaeological Archives Forum has created a mechanism with which to engage the various stakeholders in the long-term preservation of archaeological archives. By bringing these groups together, identifying common problems, and beginning to address the problems, it is hoped that a more unified approach to the care and maintenance of these important resources will be developed and put in place.

Deposition standards We need consistent standards for depositing archaeological archives across the whole country. We have completed work on reviewing current museum and record office standards for accession, charging policies, and collecting areas and policies. We will be using these reports to lever support at a national level for consistent standards across the board.

References Aitchison, K. 2004. Disaster Management Planning for Archaeological Archives. IFA Paper #8. Reading, England: Institute of Field Archaeologists.

Training It is vital that the young archaeologist begin his or her career with an appreciation for the importance of the archive resource and how it is best created and maintained. We are working to ensure that current training programs include information on the archiving of collections.

English Heritage. 2002. Archaeological Documentation, Access and Deposition: Forward. London: English Heritage.

Influencing government This is a time of policy change in English politics and the historic environment is high on the agenda. Currently we are working to influence things in two ways. We wish to ensure that new legislation includes recognition of the duty to care for the archives of archaeological investigation. The Forum has provided input into forthcoming government legislation and one of our members sits on the All Party Parliamentary Archaeology Group (APPAG).

Archive: A Way

Swain, H., A. Rennie, and K. Suenson-Taylor. 1998. A Survey of Archaeological Archives in England. London: English Heritage. Biography Kathy Perrin works for English Heritage in the Local Authority Liaison team within the Research and Standards Group. She has lead responsibility for archaeological archiving policy within English Heritage. Previous to this role she ran the Information Management and Collections section in the Centre for Archaeology at English Heritage.

We are also assisting in the production of standards for new Heritage Environment Record Centers which will evolve out of the current system of sites and monument records serving England’s counties and districts. It is planned that these will become interlinked information portals covering the whole historic environment.

Address English Heritage Fort Cumberland Eastney Portsmouth Hampshire PO4 9LD UK

Long term aim—regional resource centers It is clear to the majority of those involved in archaeology in England that we need a better answer to the issue of storage and access. The most popular solution is to build a network of large archaeological resource centers which could maintain a dual function, one of storage and the other of access and research. One such center has already been built in London by the Museum of London: the LAARC, which is operating successfully. There are a number of other such initiatives beginning to spring up across England, but most have only reached the planning stage. Centers such as these 154

CREATING AND MAINTAINING A DIGITAL ARCHIVE FOR MARYLAND’S ARCHAEOLOGICAL COLLECTIONS Rebecca Morehouse, Sara Rivers-Cofield, and Julia A. King Abstract The Maryland Archaeological Conservation Lab (MAC Lab) at Jefferson Patterson Park and Museum (JPPM) is the official repository for the State of Maryland’s archaeological collections and their associated records. To increase the availability of these archaeological collections for research, educational, and exhibit purposes, the MAC Lab, with support from the National Endowment for the Humanities (NEH), created an electronic artifact catalog including more than 30 of the state’s most significant collections. The MAC Lab has recently received further support from NEH to organize, catalog, and preserve the archaeological field and laboratory records associated with each collection and to include this information in a digitized, searchable database. Although the project will greatly increase access to important contextual and relational data essential for archaeological interpretation, only 25% of the collections at the MAC Lab are included in this effort. The MAC Lab staff still faces the challenge of forming strategies and finding funding to allow the incorporation of all collections into the systems developed during the NEH projects, including Federallyowned collections and collections without national significance, neither of which qualify for NEH funding. This paper examines the challenges faced by MAC Lab staff in implementing efforts to increase accessibility to archaeological artifacts and archives and discusses the problems of managing and maintaining the resulting databases in the face of the rapidly changing digital world.

Assume this imaginary researcher overcomes the problem of searching reports and has even located some promising sites. Next, she would like to access the artifact catalogs for these sites. If she is lucky, she might find that some of the catalogs are in searchable digital databases; however, others may exist only on paper, and the level of detail captured in the paper catalog may be low. What if the catalogs in electronic databases use different terms for the same things (i.e., ‘tack’, ‘furniture’, ‘furniture tack’, or ‘upholstery tack’)? The determined researcher may be able to overcome these obstacles, find artifacts in paper and electronic catalogs, and perhaps even locate the actual artifacts, if the collections are well-organized and accessible. But what if the site has multiple components and the researcher needs to know if a certain thimble was recovered from a 17th-century context? She will need to check the other artifacts associated with the thimble and the field records to evaluate the excavators’ assessments of the level of disturbance or date of the context. If the records are missing, in disarray, or illegible, the thimble may be no good to her, and all of the time she spent tracking it down was wasted. If the thimble is of no value to the imaginary researcher, it should be asked, to whom is it of value? Unfortunately, the challenges encountered by this imaginary researcher are all too common. Archaeologists know sites are destroyed by excavation, and that they have an ethical obligation to make sure the resulting artifacts, and the stratigraphic contexts from which they are recovered, are recorded and, for the most part, retained as a permanent record. If archaeologists agree that collections should be retained as a record of sites, then they have a responsibility to make sure that the collections are organized and documented well enough to be a viable resource. When collections are not accessible for research, the retention of archaeological materials is more akin to hoarding behavior than professional curatorial practice.

Introduction Imagine a researcher who wants to study 17th-century sewing-related artifacts recovered from archaeological sites in a given state. Anyone who has attempted to conduct such research knows the obstacles that can appear at every step in this task. This imaginary researcher begins by looking for reports about archaeological work undertaken at 17th-century domestic sites. These reports are usually gray literature documents with limited distributions, often accessible only through certain libraries at State Historic Preservation Offices, contract firms, or museums with archaeological programs. Few of the reports are found as full-text documents in databases searchable by such keywords as ‘17th-century’ or ‘sewing’. To avoid the chore of paging through each report, the researcher calls on other archaeologists for guidance. In most cases, she will get directed to well-known research projects with which her colleagues are familiar. As a result, the available data set tends to be skewed by the researcher’s professional acquaintance, and the data from many other archaeological excavations, particularly those that resulted from compliance archaeology, remain unknown and underutilized.

Archaeologists—and perhaps more correctly, the public who support archaeology through taxes and legislation— invest public funds in the long-term care and preservation of archaeological collections, in part because archaeological materials constitute a unique and irreplaceable source of information about the past, both recent and distant. But there is more, especially for those who work in publicly funded institutions. Not only do archaeologists, collections managers, and conservators have intellectual responsibilities for the materials in their care, they have ethical and fiduciary responsibilities as well, especially given limited financial resources. They have a responsibility not just to preserve materials but to create access to them. They should not only be prepared 155

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS laboratory records associated with these collections (Archaeological Records Database). It also explores the MAC Lab’s ultimate goal, which is to link the Artifact Catalog Database and the Archaeological Records Database with the Maryland Historical Trust’s (MHT) Geographical Information System (GIS) and Archaeological Sites Database (Fig. 1).

for this imaginary researcher, they should seek her out, and actively encourage her use of these collections. The State of Maryland is strongly committed to increasing collections accessibility and to facilitating the kind of research this hypothetical researcher was pursuing. In 1998, the state opened the Maryland Archaeological Conservation Laboratory (MAC Lab), located at the Jefferson Patterson Park and Museum (JPPM) in St. Leonard, Maryland. The MAC Lab serves as the repository for the majority of the archaeological collections either owned by or in the custody of the state, and through its three programs (research, collections management, and conservation) is committed to study, conserve, curate, and make accessible an estimated seven million artifacts and their associated documentation. The creation of this facility brought together three previously independent State programs: the Southern Maryland Regional Center, an archaeological research program in southern Maryland; Maryland’s Archaeological Conservation program; and Maryland’s Archaeological Collections Management program. The merger of these three programs to form one institution required research archaeologists, conservators, and collections managers to work cooperatively and created one of the first state-ofthe-art facilities solely focused on the research and preservation of archaeological collections.

The State of Maryland’s archaeological collections The State of Maryland has been collecting archaeological materials for nearly four decades, and the materials housed at the MAC Lab are probably not that different from artifacts and collections found in most archaeological repositories. Today, the collections in the State’s custody are estimated to consist of approximately seven million items recovered from more than 2,000 archaeological sites located throughout the state, representing 12,000 years of human history in Maryland. These items include artifacts, animal and plant remains, soil samples, and associated field and laboratory documentation. The overwhelming majority of the collections curated at the MAC Lab (an estimated 92.5 percent) were recovered through professional archaeological investigations in Maryland. The majority of these collections consist of so-called Phase I survey data used primarily to locate and identify archaeological sites. These Phase I collections provide valuable information for analyzing settlement patterning, technological change, environmental history, and land use. The remaining professionally excavated collections consist of site-focused projects, which in Maryland are defined as Phase II and Phase III, with the differences related to collecting information for making determinations of eligibility for the National Register of Historic Places or for purposes of data recovery. Phase II and III collections are typically considerably larger in size than Phase I collections, and result from careful, well-documented excavation of soil levels and features. These collections have the potential to yield a broader range of information about the past than do Phase I collections.

Unlike many other object collections, which consist of complete, often independently acquired or accessioned materials, archaeological collections consist primarily of hundreds or even thousands of broken or otherwise fragmented materials recovered from terrestrial or submerged archaeological sites. The value of these materials lies not just in the artifacts or fragments themselves, but also in the relationships among the materials and the stratigraphic contexts from which they derive. Making collections accessible, then, applies to both the physical materials and the stratigraphic or contextual information associated with each object. Because of the large amount of information represented by archaeological collections, the MAC Lab made the decision to create an electronic database for organizing, storing, and retrieving this information. Funding from the National Endowment for the Humanities (NEH) has been secured to enable the creation of two databases: one for artifact catalogs and another for paper and film records associated with each collection. While this multi-year project was carefully planned, the on-the-ground execution of the project revealed some challenges and problems we simply did not anticipate. In some cases, alternative methods and strategies were developed to achieve our goals. In others, problems could not be resolved and remain a part of the final product.

Approximately 7.5 percent of the collection consists of materials collected by amateur or avocational archaeologists. These materials generally lack welldocumented provenience information, although some collectors do keep records about artifact and site location. These collections, which usually consist of prehistoric materials, tend to be biased towards complete objects (e.g., points, scrapers, axes, gorgets). Despite these limitations, such collections are useful for regional analysis and locational information, especially since many of the sites represented by these collections have been destroyed by development. Avocational collections are also useful as type collections, as teaching collections, and for exhibit purposes.

This paper addresses the MAC Lab’s successes and challenges in creating an electronic artifact database for the State of Maryland’s most significant archaeological collections (Artifact Catalog Database), and the potential pitfalls that lie ahead as the MAC Lab begins the process of creating an electronic database for the field and

Of the collections at the MAC Lab, approximately 87 percent are State-owned, and were either excavated on State land or donated to Maryland by private landowners.

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REBECCA MOREHOUSE, SARA RIVERS-COFIELD, AND JULIA A. KING: CREATING AND MAINTAINING A DIGITAL ARCHIVE

Figure 1: Database links at the MAC Lab.

GIS and Archaeological Sites Database • GIS is computerized map system showing site locations • Archaeological Sites Database contains records for over 10,000 recorded sites in Maryland • Database information includes site type, basic attributes and history of site activities (including excavation history)

Artifact Catalog Database • Catalog of materials recovered from 34 of Maryland’s most significant archaeological sites • Database uses flexible, hierarchical lexicon to describe artifact attributes

Archaeological Site Field Records Database • Catalog of field records, reports, and photographic images from archaeological excavations to enable access to scanned documents • Records provide key context information for artifacts, essential for research • Database design will optimize information storage and retrieval across system

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Databases linked through archaeological site number and, where appropriate, lot number

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS collections management and conservation forms, negatives (including X-radiograph images), prints, contact sheets, slides, and any other records or analytical forms used to document, analyze, and interpret the assemblage in the laboratory. Without its associated records, an archaeological collection loses the major part of its historical value.

The remaining 13 percent are owned by the Federal government and include materials from Federal properties in Maryland (e.g., military installations, National Wildlife Refuges, etc.). At this time, the agencies managing these properties are prevented from donating or otherwise de-accessioning these collections. Federal collections are curated at the MAC Lab through cooperative agreements established between the MAC Lab’s parent agency, MHT, and the responsible Federal agency.

The State of Maryland’s most significant collections Preserving and creating access to archaeological collections of significant size, including the records, can be an undertaking of enormous scope, particularly given the limited funds available for such projects. With this in mind, the MAC Lab chose a phased approach to the long-term preservation of and increased access to its archaeological collections. The first step was to determine just what collections the MAC Lab had in its holdings and, of these, which represented the most significant sites in the state, both temporally and regionally, that may be requested by researchers, curators, educators, and students.

Materials ranging in date from the Paleo-Indian period (c. 9,000 BC) to the eve of European contact (AD 1600) comprise about 40 percent of the materials stored at the MAC Lab. Site types include base camps, resource procurement sites, fishing camps, villages, palisaded settlements, and burial sites. Approximately 59 percent of the collection consists of historic period assemblages recovered from terrestrial sites. These collections range in date from the early 17th through the 19th centuries, although 20th-century collections are increasingly represented in the holdings. These historic period collections derive from post-contact Native American, European American, and African American archaeological sites. Site types include plantation and other rural occupations (including landowner, tenant, and slave), urban domestic and commercial sites, industrial sites (including mills, furnaces, lime kilns, and pottery kilns), and military sites.

In 1999, when this project was first conceived, the existing collections management database included information on over 5,000 boxes of artifacts. This information consisted of county and site number, date of acquisition, source of acquisition, accession numbers, and so on. From this baseline data, MAC Lab staff was able to provide a rough sketch of the repository’s collections, including time periods represented, ownership, and method of recovery. This information was then used to determine the largest collections in the MAC Lab’s holdings, and those collections that, at least superficially, appeared to have the greatest potential for long-term use.

Underwater archaeological collections from historic period contexts comprise approximately one percent of the collection. These materials include artifacts from an inundated Civil War Union hospital and Confederate prisoner-of-war camp, an 18th-century shipyard, boat sections belonging to an American flotilla from the War of 1812, and a rare crosshead steam engine from a boat sunk off the coast of Point Lookout, Maryland in 1850. Additionally, numerous survey finds recovered by the Maryland Maritime Archaeological Program are included in the underwater collection.

One of the first challenges was determining the MAC Lab’s audience: for whom were the collections being preserved and made accessible? The MAC Lab staff members are state employees. They work for and answer to the citizens of Maryland and these citizens constitute an important audience for our efforts. Still, there are often many layers or steps between ‘raw’ archaeological evidence and the exhibits, presentations, and publications through which the citizens consume the state’s archaeological history. To that end, the first-level audience identified was the archaeological community, and members were invited to participate in selecting collections for this project. Their input was especially important because most of the MAC Lab’s archaeologists and collections managers are primarily historical archaeologists with a focus on archaeological collections from southern Maryland, where the MAC Lab is located. MAC Lab staff needed the input of prehistorians and of archaeologists from other parts of the state to understand the research and educational goals of these groups.

A discussion about archaeological collections usually begins with the artifacts because they represent a tangible link to the past that can be physically seen and touched. However, at least as important as the artifacts are the associated records produced in the field and laboratory. Field records are documents created on site during the course of excavation, and include provenience or level cards, stratum registers, survey logs, photo logs, maps, soil description forms, field journals, black and white negatives, prints and contact sheets, color negatives and prints, and color slides. These records document archaeological stratigraphy and features such as pits, hearths, post molds, graves, and foundations, and describe methods and processes of excavation. Since an archaeological site is destroyed through the process of excavation, field records assume exceptional importance in any effort to reconstruct archaeological context. Laboratory records include artifact catalogs, glass and ceramic vessel forms, radiocarbon dating sheets, reports,

A committee of staff archaeologists and outside colleagues chose collections with the greatest potential for future ‘use’ (defined here as research, study, or

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REBECCA MOREHOUSE, SARA RIVERS-COFIELD, AND JULIA A. KING: CREATING AND MAINTAINING A DIGITAL ARCHIVE The NEH I project also included the creation of approximately 100 digital images from color slides, prints, and line drawings of the most diagnostic and unique artifacts from each collection. These images were then linked to the individual artifact records in Re:Discovery. A select number of images were included in the project’s Finding Aid, which is a document containing a brief site description, including dates of occupation, site function, cultural period, principal investigator, level of stratigraphic control, and materials recovered. This Finding Aid was then placed on the JPPM website for use by researchers. All digital images were scanned as tagged image file format (TIFF) files. These preservation-quality images were archived on a shared drive on the local area network (LAN) at JPPM. A second set of access-quality images was created by saving the TIFF as a joint photographic expert group (JPEG) file. The JPEG images are available for research and presentations, while the TIFF remains untouched as an archive copy.

exhibition). Since the MAC Lab is part of a State agency, it was important to identify collections from all regions of Maryland and from all time periods, which was not without its challenges. Most of the collections in State custody have been generated as a result of projects preceding land development or other land use changes, so faster-growing regions of the state have far more collections in our holdings. Similarly, some time periods are better represented than others, a fact related to settlement histories of each region. Not surprisingly, these collections all derive from controlled Phase II and/or III archaeological investigations at sites listed or eligible for listing in the National Register of Historic Places. This collaborative effort resulted in the selection of collections from 34 archaeological sites ranging from the Paleo-Indian period to the early 20th century, from the mountains of western Maryland to the open fields of the state’s Eastern Shore (Fig. 2). Digitization of the artifact catalogs In 2001, the MAC Lab secured funding from NEH to develop the Artifact Catalog Database for these 34 collections. This first phase of the digitization project is hereafter referred to as NEH I. The first step in the preparation for NEH I was to make sure the collections were organized and appropriately housed for use by NEH I project staff. Some collections met then-current curation standards, or were at least in reasonable curatorial condition, while others were packaged in acidic, non-archival material. Although we generally refrain from reorganizing collections that have been delivered to us, in many cases NEH I collections were mixed by provenience or artifact material type, so MAC Lab collections management staff assessed each collection, restoring its organization and rehousing materials as necessary. The state of the collections’ artifact catalogs also had to be evaluated. Some catalogs were ready for immediate data entry into the computer database, but others needed varying degrees of revision or needed to be recataloged completely prior to data entry.

Along with the rehousing, cataloging, and photography, MAC Lab conservation staff undertook a survey and assessment of the collections that were part of NEH I. Like the rehousing and preparation of the artifact collections, this survey was not supported by NEH I funds, but was considered a logical addition to the project. Up to this point, the MAC Lab’s conservation program had focused on the conservation and stabilization of specific objects brought to their attention by collections management or research staff. The conservation staff had had only very broad discussions regarding a general survey of all the archaeological collections at the MAC Lab; therefore, NEH I gave them an opportunity to design a formal collections survey and assessment (see Wellman, this publication). Digitization of the archaeological records In 2005, the MAC Lab received additional NEH funding for the next phase of this project. This phase proposes to organize, catalog, preserve, and create computerized access to the field and laboratory records associated with the 34 chosen archaeological collections. This newest project is hereafter referred to as NEH III. The original documents, including images, will be preserved in appropriate archival housing in environmentally controlled and secure space within the MAC Lab. The Archaeological Records Database will be designed to provide computer access to these documents and will then be linked to the Artifact Catalog Database created during NEH I. These two databases will then be linked with the GIS and Archaeological Sites Database. Created in 1998 and managed by the MHT, the GIS and Archaeological Sites Database consists of a computerized map system with basic site information for over 10,000 sites in Maryland.

Once the collections were prepared and the catalogs evaluated, NEH I staff began checking artifact identifications and recataloging as necessary, and then entering the information into the MAC Lab’s Artifact Catalog Database, Re:Discovery. Re:Discovery, selected by the MAC Lab’s parent agency, MHT, in 1996, is a commercially available collections management software that can be customized for an institution’s particular needs. The choice of Re:Discovery for the Artifact Catalog Database has had some negative repercussions, in that it is not the best suited program for accessing large quantities of archaeological information. This became evident when the artifact database was put to its first real test during a subsequent NEH-funded research project designed by Dr. Julia King, co-author of this paper. The staff of this project met with major obstacles when trying to extract and manipulate data from Re:Discovery. A broader discussion of this later project, hereafter referred to as NEH II, and the challenges of this database, are taken up later in this paper.

The MAC Lab staff has estimated that 185,000 records need to be organized, rehoused, scanned, and cataloged. NEH III project staff will begin by assembling the paper, film, and Mylar records for each of the 34 collections. As with the organization of artifact collections, if the 159

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS

Figure 2: Sites included in the NEH I project.

original organization of the associated records survives, it will be preserved. In a few cases, primarily older collections, records are incorrectly filed, or media types are inappropriately mixed (e.g., black and white photographs have been glued to provenience or level cards). The organization of the records will be restored to as close to original condition as possible, with paper clips and staples removed and records straightened or flattened as necessary. Staff will perform a condition

assessment by item, following the recommendations of a paper conservator. The paper conservator will be hired as a consultant to provide staff with assessment training, help establish treatment priorities, and stabilize and/or conserve selected records. Once the records have been assembled and organized, a catalog record will then be created for each collection. This record will include the site number; site name; 160

REBECCA MOREHOUSE, SARA RIVERS-COFIELD, AND JULIA A. KING: CREATING AND MAINTAINING A DIGITAL ARCHIVE standards, however, the MAC Lab will retain the TIFF files of all reports.

accession number; dates of the collection; location(s) of the collection; types of records and record media; creator(s) of the collection; item count or quantity by linear foot; and collection arrangement. This information will provide the basis for the database.

Once the original records have been scanned, these materials will be housed in archival packaging and stored in environmentally controlled conditions. All paper records will be placed in acid-free file folders and stored in acid-free document cases. Boxed original records will be stored separately from artifacts in the MAC Lab’s Map and File Room, where temperature is maintained at 65 ±2°F and the relative humidity at 50 ±2 percent.

Archaeological collection records are necessary for relating important stratigraphic information, and it is usually the case that more than one record will apply to a specific provenience or level. Therefore, a catalog of individual records will be created for tracking purposes. Each item to be scanned (e.g., provenience card, stratum register, survey log, photo log, maps, image, etc.) will be assigned a unique identification number during the cataloging process to physically track the record item and, subsequently, the item’s digital copy. This number will be written on each record in archival ink. Throughout the database, each item will be crossreferenced with either the archaeological site number or the archaeological lot number, a numeric designation used to track artifacts by provenience within the MAC Lab. The archaeological site number and lot number will serve as linking fields between the Artifact Catalog Database and the proposed Archaeological Records Database. The record id/tracking number, lot number(s), site number, site name, accession number, record type, condition, location, collection date, count, and subject description for each record will be captured in the catalog.

Original film records will be packaged in preparation for long-term cold storage. All black and white and color negatives and prints and all 35mm slides will be placed in polyethylene slide sleeves inserted into 12- by 15-inch polypropylene ziplock bags sealed to create a microenvironment. A relative humidity indicator card will be placed in each bag for monitoring purposes. The sealed bags will be placed in a storage box in a frost-free refrigerator. A frost-free refrigerator is recommended by Henry Wilhelm, a nationally recognized authority on the care and preservation of color photographs, as an inexpensive but effective tool for enhancing long-term film stability and preservation (Wilhelm and Brower 1993). As previously noted, acid-free copies do not exist for all paper records. For these records, acid-free copies will be generated from the scanned files. These materials will then be housed in the same types of file folders and document boxes as the original records, but the copies will be stored in a special section in the MAC Lab’s Collections Storage Room.

All paper records will be scanned by the Maryland State Archives, which is being contracted by the MAC Lab for this project. All original paper field and laboratory record types, including provenience or level cards, stratum registers, survey logs, photo logs, maps, soil description forms, field journals, carbon-14 data sheets, analytical forms, and photographic records will be scanned. For documentary slide images, we estimate that approximately one-third will be selected for scanning, since many of the images are multiple exposures of the same subject. All slide, print, and negative images will be scanned in-house at the MAC Lab. As with the digital images created during NEH I, records selected for scanning will involve creating both preservation- and access-quality images. Precise tonal and color replication for the vast majority of the original paper records is not necessary and, in most cases, information contained in records can be captured at a lower resolution. Preservation-quality images will be scanned at 300 dpi as either grayscale (8 bits per pixel) for hand written/typed field and laboratory notes or color (24 bits per pixel) for color photographs and maps. These images will be saved as uncompressed TIFF files. For access-quality images, the TIFF will be saved as a JPEG. The tracking system will ensure that all documents are legibly scanned, correctly named, and appropriately organized and stored on the MAC Lab’s server.

Archaeological Records Database design The design of the Archaeological Records Database structure will begin with organizing and cataloging the records. The collections and their associated records were generated by numerous archaeologists at different times since the 1970s, and the types of records for each collection vary. A database designer will be hired to develop a prototype database based on the individual records catalog described above, with input from MAC Lab and NEH III staff. We will base the prototype design on records from three collections, representing the full range of site and record types in all 34 collections. The Fort Frederick (18WA20) collection includes records from a number of different projects conducted over the course of several years at a single site, while the Catoctin Furnace (18FR320-1, 323-4) collection includes records from a complex of several sites. The King’s Reach Quarter (18CV84) collection includes records generated through a variety of excavation methodologies and techniques (shovel testing, surface collection, and plow zone and feature excavation). The database designer will develop a relational system that will perform two functions: (1) create a searchable database, and (2) integrate with the Artifact Catalog Database and the GIS and Archaeological Sites Database. The system will be tested by staff and

For site reports, the TIFF files will be converted to ASCII text using Optical Character Recognition (OCR) to create a searchable image file in PDF format. Since PDF format is not fully adequate for digital archive 161

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS nationally significant collections qualify for NEH funding, smaller sites that might be useful for regional studies had to be excluded. Additionally, numerous Federally-owned collections that have national significance could not be included because NEH will not fund projects that should be the responsibility of another Federal agency.

consultants with a small sample of material that will be representative of the range of variability within the data. Modifications to the database and to the user interface will be made based on the prototype. One especially important requirement for this system is its integration with both the GIS and Archaeological Sites Database and the Artifact Catalog Database. The GIS and Archaeological Sites Database contains basic information about approximately 10,000 archaeological sites in Maryland, including site number, location, time period, site function, excavation projects, and related publications bibliography, and has the ability to query and display site information along with a computerized map system. The Artifact Catalog Database is also organized by site number as well as by lot number. This database will be related to the GIS and Archaeological Sites Database through the site number.

Since accessibility could not be pursued for Federal collections through NEH grants, the MAC Lab initiated a program of charging Federal agencies for curation. Federal agencies are required by the Code of Federal Regulations 36, Part 79 to care for their collections using professional archival practices. Federal agencies that are not in the archaeological curation business can contract with the MAC Lab to fulfill their congressionally mandated obligations. So far, the MAC Lab has required data entry of artifact catalogs, and included labor costs for this task in each Federal contract. This has served as a supplement to the NEH I cataloging and data entry project. The digitization of records will be offered as an optional service once the database is in place following the completion of the NEH III project. This system only works inasmuch as agencies are willing to pay. If an agency will not enter into a financial arrangement with the MAC Lab, the MAC Lab must return the collection to its owner, severely limiting accessibility. Fortunately, most Federal agencies are willing to hire the MAC Lab to fulfill their legal obligations for collections, and as a result of this program another 13 percent of the collections at the MAC Lab will be more accessible. There are currently no resources available to perform large-scale data entry and records scanning for the remaining 62 percent of the collections in the building.

The Archaeological Records Database will also use the archaeological site number as a key identifier to link to the sites database. This database will be linked to the Artifact Catalog Database through the site and the lot number. All associated materials (field maps, field records, reports, photos, etc.) can thus be related back to the artifact catalog and to the original site record. The Archaeological Records Database will be designed in Microsoft Access, which allows for flexibility in design, is easily prototyped and tested, and interfaces with existing databases. The integration of these three databases will create an especially powerful research tool. For example, a researcher using the GIS and Archaeological Sites Database will be able to select a site, move to the basic site record, select a summary report of the catalogued material from the Artifact Catalog Database, view a list of slides and photographic images, view the site map, and select specific features for further study. The Archaeological Records Database will provide an important relational context for viewing the catalog materials. If a user wants to see the part of a site a particular artifact came from, he or she could view the site maps, feature plans, and in some cases, images of the artifact in situ. Indeed, the proposed project will complete the design of a comprehensive database system for archaeological data management by handling site information, mapped locations, collections, reports, artifacts, and associated records in a unified, efficient manner.

Although this creates some difficulty in managing collections according to different ownership and significance categories, there simply is not enough permanent staff at the MAC Lab to continue performing data entry and records scanning after the support staff funded by the NEH grants leave. It is unfortunate that many significant collections had to be left out, and may still require rehousing, cataloging, and data entry, especially since incoming collections may have great significance, but there is not enough staff to integrate these collections. Clearly, it would be preferable to integrate all of the collections in the building into one comprehensive system. The limited time period and scope of the grant-funded projects also provide little time for developing alternative methods and strategies when problems arise. Throughout the NEH I project, NEH I and MAC Lab staff faced a number of challenges, which in hindsight could have been foreseen and perhaps planned for. One challenge was rehousing 34 artifact collections containing over 1500 boxes with only three collections management staff. The collections management staff at the time decided to put off preparing the majority of these collections until 2001, when the MAC Lab received confirmation that the grant was received, instead of getting a head start by beginning the rehousing process in

Limitations and pitfalls to the digitization process Although these NEH projects greatly increase access to important contextual and relational data essential for archaeological interpretation, there are several limitations and potential pitfalls that arise from relying on grant funds to digitize so much data. As with any grant-funded project, the collections accessibility project at the MAC Lab has a limited time period and scope, and therefore only 25 percent of the collections in the MAC Lab’s holdings are included in these NEH projects, leaving many collections less accessible. Since only 162

REBECCA MOREHOUSE, SARA RIVERS-COFIELD, AND JULIA A. KING: CREATING AND MAINTAINING A DIGITAL ARCHIVE impossible for NEH II staff to extract and manipulate the data in Re:Discovery, so as a result, data had to be exported into smaller Excel and Access files in order to make research feasible. This process involved running a filter (slowly) to extract the appropriate data, saving the filter, exporting the data as a text file, and then importing the text file into Access. The Access files were then generally converted to Excel files. It was discovered that this export process often results in some entries being lost to complications in the data conversion process. Entry of artifact catalogs into Re:Discovery therefore serves only to standardize and store the data. Access to that standardized data is still dependent upon the availability of staff to extract catalogs for researchers.

1999, during the project’s conceptual phase. This decision was based primarily on what were perceived as the different priorities of the collections management and research programs as well as the perceptions of the roles and responsibilities of individual staff members. This ultimately created unnecessary pressure to complete this process in a very short period of time and the collections staff scrambled throughout the NEH I project to stay one step ahead of the NEH I staff. The conservation staff ran into similar difficulties planning their conservation survey and assessment of the archaeological collections. In the beginning of the survey and assessment process there was little input from the MAC Lab’s collections management and research program or NEH I staff, primarily because MAC Lab staff identified themselves as part of an individual program (research, collections management, or conservation) and not part of a larger cooperative institution. However, as the survey and assessment progressed, increased consultation between the MAC Lab and NEH I staff refined and improved the results of this part of the project. The NEH I project was the first test of how well the MAC Lab’s programs could work together toward a larger common goal, and although the staff was faced with numerous challenges, this project resulted in greater cooperation amongst MAC Lab’s programs and assisted in defining the roles of all the MAC Lab’s collections managers, conservators, and archaeologists.

In order to reach the goal of true accessibility, MAC Lab staff members now hope to acquire funding or institutional support that will enable them to abandon Re:Discovery in favor of a more flexible database. With the lessons learned from using Re:Discovery during the NEH I and II projects, the collections staff, conservators, and researchers are much better positioned to articulate exactly what they expect of a newly designed database. Recent efforts at the National Archives and Records Administration (NARA) to scan their collections have identified numerous obstacles in the creation of a digital archive. Technology changes rapidly, and software may be obsolete within five years of its development, so all digital data must be diligently migrated in order to keep it accessible. Additionally, the persons responsible for maintaining the databases will have to check files regularly over time to make sure that data has not become corrupt or obsolete. Because of the rapid changes in software programs, preservation of digital data is actually more complex and expensive than preservation of analog data such as paper records and artifacts. Ultimately, the cost of preserving 1 MB of digital data for 10 years will be 5 to 10 times as high as the initial cost of creating that 1 MB (Puglia 2004). Given the high costs of maintaining digital data, Steven Puglia of NARA concluded that the expense involved in such a project can only be justified for archiving records that will actually be used (Puglia 1999).

As mentioned previously in this paper, one of the largest challenges the MAC Lab faced was its choice of a software program, Re:Discovery, for its Artifact Catalog Database. The MAC Lab’s particular iteration of Re:Discovery is a workhorse of a database that was designed for the MAC Lab with input from staff and the archaeological community. It is excellent at storing incredibly large amounts of detailed information and descriptive terms about artifacts. It also has filtering capabilities that allow criteria to be set for data extraction. Unfortunately, the program runs extremely slowly on the MAC Lab’s server, making the filtering process prohibitively slow. The program is quirky and the MAC Lab is heavily dependent upon support from Re:Discovery technicians to navigate the oddities of the programming. Even worse, MAC Lab staff cannot change the program as they learn what works and does not work, because Re:Discovery owns the program and the MAC Lab would have to pay them for any structural redesign.

The lessons learned at NARA have frightening implications for the MAC Lab. Database specialists hired specially to help create the database for the associated records will only be on staff for a limited amount of time, making it impossible for them to ensure that the data will be viable in the future. This leaves the responsibility for the databases with the MAC Lab collections staff, namely the Collections Manager and Federal Curator. As these individuals are already responsible for approximately seven million artifacts, plus associated paper records, photos, etc., and this number grows each year, adding digital data management to their already overwhelming workload will mean that collections management tasks will have to be sacrificed unless additional staff can be obtained to help. Such computer support might be accessible through the Maryland Department of Planning, but with the

This is especially problematic in that Re:Discovery lacks the flexibility that programs like Excel and Access have for sorting, grouping, and manipulating the data as any researcher might do in the course of an analysis. This became abundantly clear during the NEH II research project, ‘A Comparative Archaeological Study of Colonial Chesapeake Culture’, which focused on comparing 18 archaeological collections from Maryland and Virginia, seven of which were collections included in the NEH I and NEH III projects. It was virtually 163

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Archaeological Conservation Patterson Park and Museum.

specialized needs of the artifact and records databases, unreliable maintenance of the digital data is a potential pitfall that the MAC Lab staff will have to strive to avoid.

Laboratory,

Jefferson

Julia A. King received her BA in anthropology and history from the College of William and Mary in 1978, her MA in anthropology from Florida State University in 1981, and her PhD in American civilization from the University of Pennsylvania in 1990. She is an associate professor of anthropology at St. Mary’s College of Maryland. Before that, she served as director of the Maryland Archaeological Conservation Laboratory, Jefferson Patterson Park and Museum.

Even if the MAC Lab is able to maintain the digitized systems it creates, the NARA conclusion that it is only worthwhile if the data is used is indicative of the risk involved in this digitization project. At present, there is not a steady stream of researchers calling every day wanting to use the collections at the MAC Lab. As described in the imaginary researcher scenario at the beginning of this paper, however, research using collections in repositories can be prohibitively difficult, and this may explain the lack of demand for such projects. The MAC Lab therefore has to take a Field of Dreams approach, hoping that ‘if you build it, they will come’. This may involve a certain amount of proselytizing and teaching to convince people that collections are accessible, they can be used productively, and it is no longer as difficult as it has been historically. This may be best accomplished through the MAC Lab’s long-term goal of making these digitized artifact and record catalogs Web-accessible. It is hoped that through Web access, researchers will become more aware of the MAC Lab’s collections and thus be more inclined to use them, either at the MAC Lab or over the Internet.

Addresses *Rebecca Morehouse and Sara Rivers-Cofield Maryland Archaeological Conservation Lab 10515 Mackall Road St. Leonard, MD 20685 USA Julia King St. Mary’s College of Maryland 18952 E. Fisher Road St. Mary’s City, MD 20686 USA *Author to whom correspondence should be addressed

Bibliography Puglia, S. 1999. The costs of digital imaging projects. RLG Diginews 3 (5), October 15, 1999. http://worldcat.org/arcviewer/1/OCC/2007/08/08/000007 0511/viewer/file422.html#feature (accessed 15 June 2009). Puglia, S. 2004. Overview: preservation of digital media. Paper presented at the Washington Conservation Guild Meeting, December 2004, Washington, DC. Wilhelm, H., and C. Brower. 1993. The Permanence and Care of Color Photographs: Traditional and Digital Color Prints, Color Negatives, Slides, and Motion Pictures. Grinnell, IA: Preservation Publishing Company. Biographies Rebecca Morehouse received her BA in anthropology and English from the State University of New York, College at Geneseo in 1995 and her MA in anthropology/museum studies from The George Washington University in 1997. She is currently the collections manager at the Maryland Archaeological Conservation Laboratory, Jefferson Patterson Park and Museum. Sara Rivers Cofield received her BA in history from Murray State University in 2000 and her MA in applied anthropology/historical archaeology from the University of Maryland, College Park in 2002. She is currently curator of Federal collections at the Maryland

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LOST TOWNS PROJECT ARCHAEOLOGICAL ARCHIVES: PRESERVING THE RECORDS OF A DESTRUCTIVE SCIENCE AT A SMALL INSTITUTION Caralyn Roviello Fama Abstract Archaeological excavation is a destructive endeavor that by its very nature prevents the ability of subsequent researchers to replicate results. It is for this reason that archaeologists document their excavations with field notes, maps, photography, and reports to preserve the information from the excavations for posterity. However, all too often in small institutions with finite resources, preservation efforts can be limited to the site itself or the excavated artifacts, rather than all the material created by the process of excavation—the resulting documentation. For over 15 years, the Lost Towns Project of Anne Arundel County has conducted excavations at numerous 17th- and early 18th-century sites in Anne Arundel County, Maryland. These investigations have resulted in not only vast numbers of artifacts, but also an attendant mass of maps, digital and paper records, and photographic materials. To prevent potential preservation problems, the Lost Towns Project has committed to creating an archive for its archaeological records to bring order to these resources and allow greater access to them, both at the present for Lost Towns team members and visiting researchers, and in the future for those who will follow us in our efforts to learn and preserve the history of Anne Arundel County, Maryland.

in a cabinet, or to places unknown as they are loaned to colleagues, taken home to be worked on, or even misplaced ? True preservation of this type of information is guided by a different mantra, perhaps a little violent, but sincere in its urgency: ‘If you are hit by a bus tomorrow, can someone else finish (or find, or understand) your work?’ Will someone else be able to use the information after you have left? There comes a time at every institution when reflection and evaluation of existing methods inspire new efforts to make things work better, more efficiently, more effectively, and above all, in a lasting manner. These plans often grow out of times of change, such as the departure or arrival of a staff member, a new organization pattern, or a move to a new facility. It is the momentum of these types of changes that can inspire new goals and/or the achievement of goals that have lost momentum or direction. The Lost Towns Project, administered by the Anne Arundel County Trust for Preservation, undertook to establish an archiving system for our archaeological records for a multitude of reasons: 1) The project has continued to increase in size, which has, in turn, created more of everything—more documents, maps, notes, papers, reports, photographs, negatives and slides, and an ever-increasing digital record; 2) With recent staff changes, multiple office locations, and a move to a new lab facility looming, it has become evident that relying on institutional memory can be an unsuccessful and precarious system for locating records, information, artifacts, and other materials; 3) The project has increased in popularity because of our unique finds and well-developed research, and thus we have more visiting scholars, who require ready and easy access to the information that the Lost Towns Project has collected and produced.

Why create an archaeological archive? Archaeologists are ethically required to document their excavations, the deposition and treatment of artifacts and samples, and their conclusions regarding their excavations (SHA 2003). These obligations are precautions so that the information recovered by archaeology can be preserved and potentially reevaluated by future archaeologists who will not be able to go back and repeat the excavation, but may have better analytical techniques available to them that will permit a deeper insight into the information recovered. The obligation to preserve archaeological information hinges on one of the primary lessons in studying archaeology: ‘Once you dig it, it is gone’. ‘It’ refers to both the artifacts and the archaeological context of the site. This mantra is meant to impress upon students of archaeology the importance of documentation—and in particular, documenting as you dig, not just after the fact. Documentation can take many forms, and should include field notes, mapping, and photography at a minimum.

Planning phase To achieve these goals, the Lost Towns Project reached out to archivists and archives experts for guidance, but ultimately developed an archiving plan that is specific to the record-keeping needs of the project and its staff. The basis for this plan, outlined below, is to make the records more accessible for the present and organize them in a system that will last well into the future. Planning has been completed but implementation is only now occurring after several unexpected, but beneficial, delays.

While the importance of preserving information as it relates to the field is often impressed upon aspiring archaeologists, the steps for what to do after leaving the field are often overlooked or glossed over. The question then becomes, What is the point in preserving information in the field for future archaeologists (or even your own report writing) if the records disappear into the pile of papers on a desk, into vaguely labeled file folders

The first step in the planning phase was a consideration of the existing filing and organizational system: what elements of the system were working well for the staff at 165

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS the Lost Towns Project, what elements were not working well, and how much change would have to be implemented to create a reliable system, particularly one with enforceable results. Fortunately, one of the central tenets of archival arrangement is the preservation of ‘original order’, or ‘the organization and sequence of records established by the creator of the records’ (Pearce-Moses 2005). Maintaining original order not only preserves the existing relationships between records, which provides context, and but also frequently saves time and effort since the records are organized in a system that may already be recorded by the creator of the records. In other words, preserving original order helps to keep the archivist from re-inventing the wheel, and provides a system that allows greater access to items that are contextually related.

large format documents. They have shallow drawers that are wide and deep to allow large files to be stored horizontally, to prevent damage from being rolled, folded, torn or creased.

The files of the Lost Towns Project were largely organized in an intuitive manner, a natural order (or original order) that files most information by site number or site name, with a few outstanding projects that group several sites together for the time being. In addition, there were Biography, Research, and Reference files: Biography files contained detailed information on historical individuals and properties discovered through research at the Maryland State Archives and elsewhere, Research files contained staff research and reports, and Reference files contained collected articles, journals, and information. These files were arranged alphabetically by name, or in the case of the reference files, by subject.

Creating a finding aid A finding aid briefly describes the information that the files in an archival collection contain. A finding aid is made up of two sections: a narrative section that orients a researcher to the collection, and a list of all of the files and containers included in that collection (Yakel 1994:44).

For photographic and digital materials, such as slides, negatives, photographs, compact disks, and floppy drives, hanging pocket files can be used for storage within standard file cabinets. These pocket files are made of polyester or other clear plastic material, and range in a variety of configurations and qualities. It is important to note that for the preservation of these fragile media types, a storage medium that is archivally stable is essential as lower quality plastics may contain polyvinyl chloride (PVC) that can be highly damaging to photographic and digital media.

In the case of the Lost Towns Project, it seemed most logical for the finding aid to describe a site and the location of all related excavation documents. While it is likely that the site file will contain most of the related documents, some documents (such as maps) may be located elsewhere because of their format and curation needs. The finding aid also lists the contents of related Research, Biography, and Reference files for easy access.

The filing system at the Lost Towns Projects worked well for the most part, so a complete overhaul was not necessary. Instead, the major problem was finding available storage space for additional archival records and files, learning how to use the filing system, and locating files that may have wandered away from the main filing system.

To make the finding aid as flexible and adaptable as possible, it took the form of a database to enable easy searching and inventorying, and to incorporate the library of books collected by the Lost Towns Project as well. While not a finding aid in the traditional sense of an archival repository, it reflects the fact that the documents the Lost Towns Project are archiving are still in regular use and that the files they belong to may require changes as research and excavation continue.

To meet these concerns, there were three major goals: 1) Improved physical curation of the records, including large or unusually sized documents such as maps, digital files, papers, reports, and photographic materials, such as slides, negatives, and photographs; 2) the creation of a finding aid for these files; and 3) the creation of a signout system that imposes personal accountability for the movement and replacement of all files and materials. Improving physical curation To improve physical curation, the Lost Towns Project needed specialty filing materials and equipment. These included appropriate storage for unusual and large format materials, such as maps and drawings, and media storage for photographic and digital materials. The existing storage (or lack thereof) had left these materials vulnerable to unnecessary damage and wear, and minor abuses in the form of folding, rolling, and small tears around the edges that sometimes added up to a loss of information or general degradation of the resource.

Creating a sign-out system Organization is great as long as the system makes sense to everyone who has to use it. When a system does not make sense or is not convenient, it encourages people to hoard the information they need, so that they do not have to go and find it again. Then again, even with systems that make a great deal of sense and offer a great deal of convenience, there are still individuals who hold on to files longer than they should. This type of behavior can cause a great deal of frustration for others who use the system, and it is for these reasons that a sign-out system is a good idea for maintaining an archive’s organizational structure. There are many options that encourage this kind of maintenance.

Specially designed filing cabinets, often called flat files or map cases, are ideal for storage of maps and other

The Lost Towns project has yet to design an appropriate system, but conceivably, the database finding aid is a 166

CARALYN ROVIELLO FAMA: LOST TOWNS PROJECT ARCHAEOLOGICAL ARCHIVES Society for Historical Archaeology (SHA). 2003. Ethical Principles of the Society for Historical Archaeology. Available at http://www.sha.org/ about/ethics.cfm (accessed June 2009).

good place to start. A sign-out column or box could be added that would indicate the whereabouts of the material. However, it may also be a good idea to follow up with a physical placeholder system that lists the title, individual, and sign-out date, to start a paper trail for the file that is easy to understand and is also recyclable.

Wilsted, T., and W. Nolte. 1991. Managing Archival and Manuscript Repositories. Chicago: Society of American Archivists.

Conclusion The original concept for this paper included the planning, implementation, and evaluation of the new archival system for the Lost Towns Project of Anne Arundel County. Due to delays in the construction of the new Lost Towns facility, progress toward these stages has been greatly slowed. Despite this, the additional time and the exercise of writing this paper allowed for discussion and for revision to the plans that might not have happened otherwise. For instance, staff discussions revealed a desire to include the reference files and library of books within the database, an adaptation that seems quite logical and should synthesize easily. In addition, time for reflection on the plan has allowed for fundraising, which has been fruitful in the form of a mini-grant from the Small Museum Association.

Yakel, E. 1994. Starting an Archive. Lanham, MD: Scarecrow Press. Biography Caralyn Roviello Fama received her MA in museum studies from The George Washington University in 2004 and her BA from St. Mary’s College of Maryland in 2001. She has worked in archaeology and collections management at Historic St. Mary’s City and has been with the Lost Towns Project since September 2004. Address Anne Arundel County Archaeology Office of Environmental and Cultural Resources 2664 Riva Road, MS 6402 Annapolis, MD 21401 USA

Archaeology is about understanding the past, and preserving the past for the future. It is a science fraught with pitfalls, exceptions, and vagaries, and is often on the budgetary chopping block because of its expense, but it is also a science that brings people together across time through an understanding and appreciation of the lives of those who came before us. Preserving the information we discover through archaeology is part of our duty as stewards of history. Bibliography Ellis, J. 1993. Keeping Archives. 2nd ed. Sydney: D. W. Thorpe. Gleeson, M., E. Williams, and P. Young. 2005. The preservation of archival materials in archaeological collections. Journal of Middle Atlantic Archaeology 21: 23. Miller, F. 1990. Arranging and Describing Archives and Manuscripts. Chicago: Society of American Archivists. O’Toole, J. 1990. Understanding Archives and Manuscripts. Chicago: Society of American Archivists. Pearce-Moses, R. 2005. A Glossary of Archival and Records Terminology. Chicago: Society of American Archivists. Also available at http:// www.archivists.org/glossary (accessed June 2009). Pugh, M. 1992. Providing Reference Services for Archives and Manuscripts. Chicago: Society of American Archivists. Ritzenthaler, M. 1993. Preserving Archives and Manuscripts. Chicago: Society of American Archivists.

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A TALE OF THREE SURVEYS: CREATING A FLEXIBLE CONDITION SURVEY FOR MIXED ARCHAEOLOGICAL COLLECTIONS Howard Wellman Abstract Conservation condition surveys are an integral part of long-term collections care. The structure and design of a survey is dependent upon the specific questions that it is intended to answer, and care must be taken to collect the appropriate data so as not to waste time and resources. Surveys intended to collect information pertinent to conservation programs may also turn out to be useful for other purposes, including collections management and research. Three case studies are discussed, demonstrating an evolving approach to assessing large collections of mixed archaeological materials using readily available survey tools and electronic databases.

With the rise of preventive conservation as a conservation and management tool, attention turned to the maintenance of storage facilities and the provision of proper climate controls as an alternative to collectionwide interventive treatments. Collection condition surveys have been used to gauge the quality of care for collections and to identify areas in the physical plant or management strategies that may need change or improvement (Holmberg and Johansson 1996; Moore 1996; Ramer 1987; Walker and Bacon 1987). Surveys also provide conservators with information so that they may set priorities and allocate resources for the treatment of individual artifacts or collections. Dollery (1994) set out a strategy for sampling an entire museum collection in order to design a long-term conservation program. The initial results were encouraging to both the conservation and curatorial staff, although the survey process itself had to be modified during the survey. This seems to be a frequent problem with surveys, and is discussed with the case studies below.

Introduction Condition survey of collections is an established tool for conservators and collection managers. Whether done by sampling a portion of the collection or as an object-byobject assessment, the survey provides data about the state of a collection that can be useful for setting management priorities, assessing storage facilities, or planning conservation strategies. Given the scarcity of resources for managing and conserving large archaeological collections, having accurate data for longrange plans is crucial. This paper discusses different approaches to surveying archaeological collections, with an aim to develop a flexible model applicable to both large collections of mixed materials (iron, ceramic, glass, etc.) and collections focused on specific artifact types. The importance of collecting information that is useful to all the ‘stakeholders’ in an archaeological collection is stressed. In this paper, I discuss three case studies that evaluate different ways to approach this problem.

A growing use of surveys is the analysis of historical or proposed conservation treatments. These surveys, based on epidemiological models (clinical studies), bring a level of scientific rigor and statistical validity to the data that allow conservators to minimize issues of bias and subjectivity when judging the outcome of treatments on specific materials (Newey et al. 1993; Suenson-Taylor and Sully 1996, 1998; Suenson-Taylor et al. 1999; Sully and Suenson-Taylor 1996; Williams and Harnett 1998). The addition of formal hypothesis testing (Taylor and Watkinson 2003) adds yet another level of objectivity to the interpretation of this survey data, and can also be used with general condition surveys.

The reasons and strategies for performing a survey are increasingly well documented in the conservation literature. Keene (1991, 2002) is frequently referenced for setting one of the early benchmarks for standardized collection surveys, specifically distinguishing between the purpose of general collection condition surveys, and conservation assessments: ‘collection condition surveys are surveys undertaken in order to assess, or audit the condition of collections as a whole, rather than to identify objects requiring action’ (Keene 1991). Her greater point is the emphasis on performing a general survey in cooperation with curatorial staff before performing a detailed assessment to identify specific conservation issues. One problem with the literature is a confusion of terms: ‘survey’ can be used to describe a wide range of information gathering strategies, and ‘assessment’ can mean either a broad general survey, or a precise object description. In this paper, ‘collection condition survey’ will retain the meaning of a broadbased collection of data about the whole collection and its setting, while ‘condition assessment’ will mean the inspection and description of individual objects.

While the principal stakeholders of archaeological resources are the owners of the collections (whether the tax-paying public or descendant communities), there are three groups concerned with collections care who represent those stakeholders: archaeologists and other researchers interpret collections for the principal stakeholders and their own research interests, conservators maintain the physical stability of the individual artifacts so all stakeholders can continue to use them, and collections managers must maintain and control the collections to ensure accessibility by the all other parties. Surprisingly, the three groups often work separately (and sometimes at cross-purposes), rather than pooling information and resources. In the case of surveys, multiple teams may be trolling through the collections simultaneously, collecting duplicate information and wasting resources in the process. Integrated surveys are a better use of scarce resources and increase the amount of information available to all users. 169

THE CONSERVATION OF ARCHAEOLOGICAL MATERIALS: CURRENT TRENDS AND FUTURE DIRECTIONS Any properly conducted survey must have strictly defined objectives to avoid collecting extraneous information, an issue strongly advocated by Henderson (1997) and emphasized by Dollery (1994), who attempted to use a ‘one size fits all’ format but then found it had to be modified mid-survey. The KamanKalehöyük survey tried to address the concerns of all stakeholders during the design phase, and made only minimal changes to the format during the data collection. Dr. Omura and ceramics analyst Kimiyoshi Matsumura were concerned about the stability of vessels, all of which were slated to be moved to a new storage facility then in the planning stages. The registrar was concerned that the artifacts were not fully recorded in the central catalog database. The director of conservation, Glenn Wharton, was concerned that past treatments and materials used for reconstruction were not recorded in the conservation database (cleaning, desalination, and reconstruction of ceramics at Kaman-Kalehöyük were historically performed by a locally trained technician under the direction of the ceramics analyst— conservators provided materials and gave advice, but no records were kept). Sara Moy, an intern from the conservation program at the Institute of Archaeology, University College London, was researching the performance of adhesives used in ceramic reconstructions. The survey was thus intended to capture administrative information (object identification and location), conservation history, and current physical state. The reports generated by the survey would be used in the short term by Moy to investigate rates of adhesive failure, and in the long term by Wharton and Matsumura to make stabilization plans and by the registrar and Matsumura to augment the site catalog.

Condition assessment surveys As noted above, there are different goals for general condition surveys and condition assessment surveys. Both styles have been discussed thoroughly in the literature, and are a recognized necessity for any collection. By their nature, general condition surveys tend to be based on a sample of the collection, and focus on identifying large-scale problems in collections care. They are frequently used as the basis (both in survey design and in fund-raising) for assessment surveys that look at a collection (or subset of a collection) in more detail (see Keene 2002, chapter 9 for detailed case studies on how to lay out a pilot survey). For several years, I (supported by staff and interns) have been engaged in performing condition assessments on a variety of archaeological collections that represent the full range of artifacts and materials types one might expect to encounter. In all cases, the principal goal has been to assess the conservation needs of all the objects in the collection, although other information has also been gathered at the same time. There was no attempt at statistical sampling since it was a curatorial and conservation decision that every artifact or bulk material group in the collection had to be assessed for specific conservation issues. Because of the scale of the projects, and because of the changes in staff that took place during some of these surveys, any examination and recording process had to be easy to learn, efficient to use, and as free of assessor bias as possible. These efforts were also closely tied to my attempts to improve the collection of data by using readily available computer database software to collect, organize, and analyze the results. These surveys represent my attempt to build on the work that has gone before, to create a survey tool that allows for the simple and efficient assessment of large archaeological collections, flexible enough to be used on mixed materials from different time periods. Three case studies are presented here to illustrate the value of integrating all the stakeholders of the collection, the problems encountered, and the solutions discovered.

Most collection surveys fall into two main groups—those that assign a numerical condition score based on observed attributes, or those that assign a prioritized condition class (e.g., high, medium, low) based on the need perceived by the surveyor. In addition, the actual conditions are noted either by descriptive commentary, or by referencing rated condition criteria. In this case, we wished to generate a numerical score free of surveyor bias, based only on observed conditions. The collected scores could be statistically analyzed to determine how to best allocate resources. There was no attempt to attribute causes to the observed conditions during the survey, as this would be addressed by Moy’s research.

Archaeological ceramic assessment survey—a ‘hybrid’ format My first attempt at creating a simple computerized assessment survey was during the 1999 excavation season at Kaman-Kalehöyük, near Kirshehir, Turkey (Wellman and Moy 2000). This site has been excavated under the direction of Dr. Sachihiro Omura of the Middle Eastern Culture Center in Japan since 1986. The site has had a seasonal on-site conservation staff since the beginning, with a considerable increase in conservation activities after 1991. In addition to conserving recently excavated objects, the conservation staff monitors artifacts held in storage and performs a periodic survey of objects loaned to the regional museum (Carroll and Wharton 1996; Wellman 2000). In 1999, the director requested a survey of excavated and reconstructed ceramics held in the Eski (Old) Depot. Conservators, the registrar, and the project director were all concerned about collection condition issues that had been developing over many years.

With these goals in mind, the survey was designed by Wellman and Moy with input from Matsumura. For ease of use, the survey form was organized to capture condition information as true/false responses to simple descriptive phrases (see Table 1). Following the lead of Suenson-Taylor and Sully, the descriptions were phrased to minimize subject bias (a problem illustrated but not resolved by Newey et al. 1993) and focus on simple condition issues that related specifically to the class of objects being surveyed: archaeological ceramics. I call this survey format a hybrid: it combines elements of both a traditional descriptive survey, and a criterion anchored rated scale (CARS) survey. Administrative information 170

HOWARD WELLMAN: A TALE OF THREE SURVEYS was collected from Matsumura’s records.

the

object

labels

or

separated from their contextual information. completeness of the vessel was a curatorial conservation resource issue—complete vessels deemed more important for diagnostic purposes partial vessels or sherd collections.

from

Every condition class that was marked ‘true’ received a value that contributed to the total condition score for each vessel. These values were weighted by the surveyors during the design phase to emphasize issues that could lead to the loss of objects or critical information during relocation. Housing or soiling were not considered major issues as they would normally be dealt with during the move itself, but any kind of physical instability in the ceramic, Condition Class % Complete

Storage Housing Labels

Body Surface

Soiling Joins

Fills

Description

The and were than

The survey database was created using FileMaker Pro on an Apple Macintosh notebook computer, which could be taken into the depot. The on-screen form was formatted as a series of ‘tick’ boxes to speed data collection (although administrative data had to be typed in). In this way, a good number of vessels could be assessed during the working day. The electronic form was formatted to assign the weighted score to each condition class, and calculate a running tally for each vessel. Based on the weighted values, each vessel would fall into one of four conservation priority classes (Table 2) which was also calculated and displayed on the screen. Simple report formats would list the objects, identification numbers, total score, and priority class.

Score

< 25%

2

25 – 50%

4

> 50%

6

> 75%

10

Open

1

Covered

0

None

2

Supported

0

None

4

Ink on the object

0

Tape label

2

Tied with string Tied with plastic or coated wire Label on bag

0

Table 2: Kaman Kalehöyük Ceramic Priorities

0

Stable

0

Unstable

7

Stable

0

Flaking

7

Friable

7

None

0

Dirt or residues

2

None

0

The decision to use weighted values, rather than ordinal ranking, was because we wanted a flexible system where the same data could be re-weighted to highlight different issues (such as the rate of adhesive failure, or the effects of depot environment) within the collection and to make it accessible by very simple grouping procedures available in the software. Essentially, we were making the system open to specific subjective decision making after the survey was complete. While this makes the data suspect from an analytical point of view, none of the surveyors had significant statistical training, nor were we trying to prove or disprove any hypotheses that would require rigorous analysis.

Stable

0

Aging adhesive

7

Failed

7

None

0

Stable

0

Cracked

7

0

Priority

Description

Score Range

1

serious failures

> 15

2

13 – 15

3

minor failures requires rehousing/support

4 – 12

4

stable