Water Management in Gerasa and Its Hinterland: From the Romans to Ad 750 (Jerash Papers, 10) 9782503598628, 2503598625

Table of contents :
Contents
Chapter 1. Introduction
Chapter 2. Information Sources and Methodology
Chapter 3. Natural Environmental Contexts
Chapter 4. Historical Contexts
Chapter 5. Water Sources
Chapter 6. Water Transport
Chapter 7. Water Storage
Chapter 8. Water Use
Chapter 9. Urban Water Infrastructure
Chapter 10. The Combined Intramural Water Transport, Storage, and Distribution Network
Chapter 11. Conclusions
Appendices
Bibliography

Citation preview

Water Management in Gerasa and its Hinterland

JERASH PAPERS General Editors Achim Lichtenberger, Westfälische Wilhelms-Universität Münster Rubina Raja, Aarhus Universitet

VOLUME 10

Water Management in Gerasa and its Hinterland From the Romans to ad 750

David Donald Boyer

British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library.

© 2022, Brepols Publishers n.v., Turnhout, Belgium All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of the publisher. ISBN: 978-2-503-59862-8 e-ISBN: 978-2-503-59863-5 DOI: 10.1484/M.JP-EB.5.127653 ISSN: 2736-7134 e-ISSN: 2736-7142 D/2022/0095/25 Printed in the EU on acid-free paper

Contents

List of Illustrations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Author’s Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv Abbreviations Used in the Text. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxvi Glossary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxvii Chapter 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Volume Content.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Part 1. Study Approach and Contextual Background Chapter 2. Information Sources and Methodo­logy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 The Study Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Chrono­logy and Naming Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . 8 Previous Studies Related to Water Management.. . . . . . . . . . . . . . . . . . . . . . 8 Water Management Studies in the Study Area. . . . . . . . . . . . . . . . . . . 8 Water Management Studies in the Southern Levant. . . . . . . . . . . . . 11 Past Field Surveys.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Primary Literary and Non-Literary Sources. . . . . . . . . . . . . . . . . . . . . . . . . . 13 Secondary Literary Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Nineteenth-Century Sources.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Post-Nineteenth-Century Sources.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Visual Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Ground Photo­graphy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

vi

Contents Aerial Photo­graphy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Satellite Imagery.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New Field Surveys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terrestrial Carbonate Studies.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Materials and Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Archaeometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio­carbon Dating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20 21 21 24 24 25 25 25 26

Chapter 3. Natural Environmental Contexts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physio­graphy and Geomorpho­logy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Topo­graphy and Relief.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Palaeolandscape History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modern Climate.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Palaeoclimate.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geo­logy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pre-Quaternary Geo­logy.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quaternary Geo­logy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Regolith.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Colluvium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vegetation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydro­logical Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Hydro­logy.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subsurface Hydrogeo­logy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismic History.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismo­logical Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Earthquake Record in Gerasa. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29 29 29 29 33 33 36 37 37 38 45 45 49 55 57 59 60 61 71 71 71 89

Chapter 4. Historical Contexts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Surface Surveys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Settlement History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Pre-Bronze Age.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Bronze Age.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Iron Age. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Hellenistic Period (332 bc to 64 bc). . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Nabataean Period (300 bc to ad 106). . . . . . . . . . . . . . . . . . . . . . . . . 101 Roman Period (64 bc to ad 324). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Contents

vii Byzantine Period (ad 324 to 640). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Umayyad Period (ad 640 to 750). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Part 2. The Hydraulic System Chapter 5. Water Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Runoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impermeable Surface Runoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Permeable Surface Runoff (Overland Flow).. . . . . . . . . . . . . . . . . . . Groundwater Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wells.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Relationship between Water Availability and Settlement Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

113 113 113 113 114 115 115 115

Chapter 6. Water Transport. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transportation by Natural Surface Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . Artificial Structures Employed to Control and Harness Hillslope Runoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel Flow Structures.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transportation by Spring-Fed Aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . Rock-Cut Aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aqueducts Constructed of Masonry or Field Stones. . . . . . . . . . . Pipelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aqueduct Bridges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conduit Hydraulics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methods Adopted to Overcome Issues Affecting Aqueduct System Design and Operation. . . . . . . . . . . . . . . . . Aqueduct Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aqueduct Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Upper Jarash Valley (Upper Wadi Suf ) Sector. . . . . . . . . . . . . . . . . Central Jarash Valley Sector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . City Area–East Bank Sector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . City Area — West Bank and Bab Amman. . . . . . . . . . . . . . . . . . . . . Southern Jarash Valley Sector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jarash–Zarqa River Junction Sector. . . . . . . . . . . . . . . . . . . . . . . . . . . Majarr–Tannur Valley Sector.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control and Management of the Aqueduct Networks. . . . . . . . . . . . . . . General Comment on Water Rights. . . . . . . . . . . . . . . . . . . . . . . . . . . Control of Water Resources in the Study Area. . . . . . . . . . . . . . . . .

131 131

128 129

131 134 139 139 149 152 156 157 159 162 163 167 168 176 176 181 183 184 186 186 186

viii

Contents Carbonate Sediment Lining Aqueducts.. . . . . . . . . . . . . . . . . . . . . . . . . . . . Dating of Aqueducts.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio­carbon Dating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Evidence for Pre-Roman Aqueduct Networks.. . . . . . . . . . . . . . . . . Discussion and Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

188 190 190 193 195

Chapter 7. Water Storage.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reservoirs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intramural Reservoirs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Possible Reservoir Installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extramural Reservoirs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reservoirs South of the City. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage Basins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intramural Storage Basins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extramural Storage Basins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cisterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intramural Cisterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extramural Cisterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

197 197 197 198 201 204 213 215 215 229 231 233 239 246

Chapter 8. Water Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Private Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Public Use.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bathhouses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fountains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ornamental Basins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Latrines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ecclesiastical Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cultic Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Primary Industry Water Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agriculture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extraction Industries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Secondary Industry Water Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Textiles and Leather. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Watermilling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Olive Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wine Production. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Metal and Glass-Working. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

247 247 247 247 256 267 271 272 272 274 274 280 281 281 282 283 283 283 284 284

Contents

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Part 3. The Urban Network Chapter 9. Urban Water Infrastructure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water Transport Installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extramural Aqueduct Networks Supplying the City. . . . . . . . . . . Aqueducts within the Western Side of the City. . . . . . . . . . . . . . . . Aqueducts within the Eastern Side of the City. . . . . . . . . . . . . . . . . Pipelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water Storage, Flow Regulation, and Distribution Installations. . . . . . Reservoirs and Storage Basins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Piscinae and Flow Regulation Basins. . . . . . . . . . . . . . . . . . . . . . . . . . Water Distribution Installations (castella divisoria).. . . . . . . . . . . . Drainage and Sewage Disposal Installations. . . . . . . . . . . . . . . . . . . . . . . . First-, Second-, and Third-Order Drains. . . . . . . . . . . . . . . . . . . . . . . Fourth-Order Collector Drains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sewage Disposal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 10. The Combined Intramural Water Transport, Storage, and Distribution Network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Areas Serviced by the Main Supply Aqueducts. . . . . . . . . . . . . . . . . . . . . . Methodo­logy.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interpretation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distribution to castella divisoria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Evolution of the Urban Water Distribution and Storage System. . . . . First Century bc/ad to ad 106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ad 106 to ad 150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Second Half of the Second Century. . . . . . . . . . . . . . . . . . . . . . . . . . . Third and Fourth Centuries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fifth to the Mid-Seventh Centuries. . . . . . . . . . . . . . . . . . . . . . . . . . . Mid-Seventh Century to ad 750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Changes in Urban Water Management in the Byzantine Period. . . . . . Changes in the Physical Environment. . . . . . . . . . . . . . . . . . . . . . . . . Societal Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Changes to the Water Distribution System. . . . . . . . . . . . . . . . . . . . Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Gerasene Water Management System in the Context of the Decapolis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sources.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydraulics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

287 287 287 288 294 296 298 299 299 299 302 303 309 312 314 317 317 317 317 318 319 319 321 322 324 325 326 328 329 329 330 331 332 333 333 333 334 334

x

Contents Urban Distribution Network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 Irrigation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335

Chapter 11. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water Distribution and Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Urban Water Supply and Distribution. . . . . . . . . . . . . . . . . . . . . . . . . Water Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Effects of Climate Change and Natural Disasters. . . . . . . . . . System Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Impact of the Hydraulic System on Development.. . . . . . . . . Concluding Remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

337 338 338 338 338 339 339 340 340 341 341

Part 4. Appendices Appendix A. Early European Visitors to Jarash Who Recorded Water Features: 1812–1875. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Appendix B. Early Aerial Photo­graphic Coverage of the Study Area.. . . . . . . . . . . . . . . . 346 Appendix C. Jarash Water Project Site Database.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Appendix D. Radio­carbon AMS Dates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 Appendix E. List of Seismic Events in Gerasa.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Appendix F. Catalogue of Important Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 Appendix G. Catalogue of Recorded Aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Appendix H. Bathhouses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 Appendix I. Fountain Catalogue.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 Appendix J. Castellum Catalogue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 Appendix K. Flow Rate Formulae.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491

Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 Index of Localities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519

List of Illustrations Plates Colour Plate 1. Slope map of the study area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Colour Plate 2. Map of drainage catchments and current dendritic drainage lines in the study area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Colour Plate 3. A representation of the relative strength of spring discharge in the context of aquifer source and the distribution of deeper soils. . . . 69 Colour Plate 4. Sites recorded in surveys in the period 1895–2012. . . . . . . . . . . . . . . . 94 Colour Plate 5. Map showing the relationship of Late Roman–Byzantine and Byzantine sites and spring locations. . . . . . . . . . . . . . . . . . . . . . . . 130 Colour Plate 6. An interpretation of the historical upper Wadi Jarash springfed canal network based on modern networks, showing sources, canal alignments, and the location of known Byzantine sites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Colour Plate 7. The distribution of olive and wine press installations in the study area in the context of the irrigated areas. . . . . . . . . . . . . 279 Colour Plate 8. The distribution of olive and wine press installations in the city area and central Jarash valley in the context of the irrigated areas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Colour Plate 9. A schematic interpretation of aqueduct alignments in the south-western part of the Artemis upper terrace. . . . . . . . . . . . . . . . . 290 Colour Plate 10. A sketch map showing the potential supply area for extramural aqueducts and aqueducts and intramural springs delivering water to the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316

Figures Figure 1.1.

Gerasa in the context of the other cities of the Decapolis and modern political boundaries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2.1.

The regional physio­graphical setting of the study area. . . . . . . . . . . . . . . . . . 6

Figure 2.2.

A contoured digital surface model (DSM) of the study area. . . . . . . . . . . . 6

Figure 2.3.

Map of the study area showing drainage lines and key spring loca­ tions within the Jarash valley and Majarr–Tannur valley catchments. . . . . 7

Figure 2.4.

The boundary of the study area in the context of the boundaries of the Jarash Basin and Zarqa River Basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

xii

L ist of Illustrations

Figure 2.5.

The boundaries of geo­graphically selective regional surveys and more detailed surveys impacting the study area. . . . . . . . . . . . . . . . . . . 12

Figure 2.6.

A map of a 5 km2 area west of the modern village of Umm Qantarah Al Gharbiyya in the Majarr valley. . . . . . . . . . . . . . . . . . . . 12

Figure 2.7.

Plan de Djérasch (Gérasa) by Gottlieb Schumacher. . . . . . . . . . . . . . . . . . . 16

Figure 2.8.

Engraved photo­graph of the western side of Gerasa, one of three views taken by George Keith in 1844. . . . . . . . . . . . . . . . . . . . 19

Figure 2.9.

Litho­graphed photo­graph of the western side of Gerasa taken in 1858 . 19

Figure 2.10. Topo­graphic plan showing the location of Jarash Water Project sites . . . 22 Figure 2.11. Location of Jarash Water Project sites in the central part of the study area in their topo­graphical and hydro­graphical contexts . . . . . . . . . 22 Figure 2.12. Chart showing the breakdown of structural types recorded during the study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 3.1.

Contour map of the study area showing the disposition of the plateau segments within the eroded terrain. . . . . . . . . . . . . . . . . . . . 28

Figure 3.2.

Map of the location of wadis in the city area in the pre-Roman period. . 31

Figure 3.3.

Diagram showing the location of key topo­graphical landscape features in the city area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 3.4.

Climate classification map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 3.5.

Average rainfall map based on data from 1977. . . . . . . . . . . . . . . . . . . . . . . 34

Figure 3.6.

Bar chart showing Jarash rainfall in the period 1942–2008. . . . . . . . . . . . 34

Figure 3.7.

Jerash Bridge Weather Station data 1980–2013. . . . . . . . . . . . . . . . . . . . . . 35

Figure 3.8.

Simplified bedrock geo­logy map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 3.9.

Aerial views of karst calcrete landscapes in the Jarash valley. . . . . . . . . . . . 39

Figure 3.10. The unconformable contact between Pleistocene Jarash Conglomerate and the underlying Upper Cretaceous Na’ur Formation at Qairawan Cave spring on the eastern bank of Wadi Jarash in the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Figure 3.11. Oblique aerial view of the Bab Amman mesa, looking north-east. . . . . . . 40 Figure 3.12. Exposures of Jarash Conglomerate in the vicinity of Gerasa. . . . . . . . . . . . 41 Figure 3.13. Photo­graphs of sites showing exposures of Jarash Conglomerate in the vicinity of Gerasa identified in Figure 3.12. . . . . . . . . . . . . . . . . . . . . 42 Figure 3.14. Examples of possible flint lithic artefacts embedded in the Jarash Conglomerate at Bab Amman. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Figure 3.15. Soil characterization map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

List of Illustrations

xiii Figure 3.16. Profile through the base of a terrace east of the Hippo­drome at Bab Amman showing an anthrosol and cultural deposits lying on natural Red Mediterranean Soil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Figure 3.17. Examples of in situ Red Mediterranean Soil profiles developed on limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Figure 3.18. Examples of homogeneous RMS soils sitting directly on bedrock. . . . . . 47 Figure 3.19. Regolith profile at the South-West Gate (looking west) showing the development of sheet-wash gravels at the base of the profile exposed outside the gateway. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Figure 3.20. Examples of deposits of colluvial gravels from the western side of the city area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Figure 3.21. Evidence of the deposition of gravels in the fourth century. . . . . . . . . . . . 51 Figure 3.22. Slope map of the study area, highlighting areas of steep slopes within the main valleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Figure 3.23. Colluvium deposits at Ficus Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Figure 3.24. Debris flow deposits at Ficus Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Figure 3.25. Natural vegetation maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Figure 3.26. Map showing the revised position of the eastern boundary of the Jarash Basin along prominent watersheds in the context of the original basin boundary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Figure 3.27. A longitudinal profile of the Jarash valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Figure 3.28. Map showing the location of modern springs based on data from Table 3.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Figure 3.29. Map showing the location of relict springs identified, based on data from Table 3.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Figure 3.30. Diagrams showing flow rates for Maghasil, Birketein, and Qairawan springs in 1938–1939. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Figure 3.31. Bar chart showing a comparison of flow rates depicted in Figure 3.30. . . 67 Figure 3.32. Bar chart diagram showing monthly flow rate record for Qairawan spring, November 1983 to August 1993. . . . . . . . . . . . . . . . . . . 67 Figure 3.33. Map showing the distribution of very strong springs. . . . . . . . . . . . . . . . . . 69 Figure 3.34. Tectonic map and relief map showing the seismo­logical and topo­ graphic setting of the Dead Sea Transform and surrounding areas. . . . . . 70 Figure 3.35. Map showing the epicentres of major historical earthquakes (movement magnitude Mw 5.0–7.7) associated with the Dead Sea Transform between 31 bc and ad 1900 in the Jor­dan­ian region and their locational uncertainty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

xiv

L ist of Illustrations

Figure 3.36. Map showing the epicentres of major earthquakes (Mw >5.0) related to the Dead Sea Transform within 160 km of Gerasa in the period 33 bc to ad 750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Figure 3.37. Archaeo­logical and 14C dating evidence of earthquake tumble beside the Qairawan aqueduct substructio at site JWP111. . . . . . . . . . . . . 74 Figure 3.38. Photo­graphs of the basilica of St Theodore’s Church during excavation showing the orientation of fallen columns. . . . . . . . . . . . . . . . . 75 Figure 3.39. Examples of the impacts of horizontal shear stress on columns. . . . . . . . . 76 Figure 3.40. Examples of seismically induced column capital rotation from the colonnade surrounding the Oval Piazza. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Figure 3.41. Examples of seismically induced block separation. . . . . . . . . . . . . . . . . . . . 78 Figure 3.42. Nymphaeum buttress wall construction phases. . . . . . . . . . . . . . . . . . . . . . . 79 Figure 3.43. Views of the buttress walls on the southern elevation of the Nymphaeum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Figure 3.44. Stylized block diagrams of various land-movement types. . . . . . . . . . . . . . 81 Figure 3.45. Examples of toppling damage to bedrock agricultural installations adjacent to escarpments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Figure 3.46. Examples of damage to aqueducts constructed on the edges of escarpments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Figure 3.47. Maps showing landslide susceptibility in the southern Jarash valley. . . . . 84 Figure 3.48. Map showing landslide events in the southern Jarash valley in the vicinity of the Der Abu Saedi locality interpreted from a 1930 aerial photo­graph. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Figure 3.49. Views of the southern end of the historical Bab Amman landslide on the eastern slope of the Bab Amman mesa. . . . . . . . . . . . . . . . . . . . . . . . 85 Figure 3.50. Views of the historical Wadi Suf landslide at site JWP194. . . . . . . . . . . . . 86 Figure 3.51. A sectional view through a historical debris flow lying on a palaeosol within the Wadi Suf landslide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Figure 3.52. Examples of landslides in the Jarash valley. . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Figure 4.1.

Examples of primitive agricultural installations. . . . . . . . . . . . . . . . . . . . . . . 90

Figure 4.2.

Early bedrock agricultural installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Figure 4.3.

Examples of olive mill installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Figure 4.4.

Examples of larger winery installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Figure 4.5.

Aerial views showing the landscape setting of Chalcolithic sites Dahara El Beida and Iraq El Bir on the watershed between the Jarash and Majarr–Tannur valleys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

List of Illustrations

xv Figure 4.6.

Map showing the location of Hellenistic (second–first centuries bc) archaeo­logical sites in the city area, mentioned in the text. . . . . . . . . 99

Figure 4.7.

Map of the northern boundary of the Nabataean kingdom around 85 bc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Figure 4.8.

Map of sites identified as ‘Early Roman’ or ‘Roman’ from published regional surveys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Figure 4.9.

A modern aerial view of the site of Der Abu Saedi in the southern Jarash valley, looking north. . . . . . . . . . . . . . . . . . . . . . . . 104

Figure 4.10. Der Abu Saedi. Plan of archaeo­logical features interpreted from a stereoscopic study of aerial photo­graphs taken in 1953. . . . . . . 105 Figure 4.11. Map of Byzantine site locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Figure 4.12. Map of Byzantine, Umayyad, and Mamluk site locations. . . . . . . . . . . . 109 Figure 5.1.

Schematic hierarchical representation of water sources. . . . . . . . . . . . . . 113

Figure 5.2.

Location of wells. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Figure 5.3.

Map of the main spring sources in the upper Suf valley. . . . . . . . . . . . . . 117

Figure 5.4.

Map of the main spring sources in the central Jarash valley. . . . . . . . . . . 118

Figure 5.5.

The location of the three zones of springs recognized in the city area. 120

Figure 5.6.

Map showing the location of Qairawan Cave spring in relation to Qairawan spring and the Church of the Prophets, Apostles, and Martyrs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Figure 5.7.

A relict cascade spring site in the city’s North-West Quarter, looking south. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Figure 5.8.

A relict spring site associated with a reservoir in the city’s NorthWest Quarter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Figure 5.9.

Examples of relict cascade springs in the city’s South-West Quarter. . . 124

Figure 5.10. Map of the main spring sources in the southern Jarash valley and the Wadi Tannur valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Figure 5.11. Map showing the relationship between strong springs and sites identified as Early Bronze I and II. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Figure 5.12. Map showing the relationship between strong springs and sites identified as Hellenistic or Early Roman from published surveys. . . . . 128 Figure 5.13. Map showing the relationship between strong springs and Late Roman–Byzantine and Byzantine sites. . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Figure 6.1.

Aerial photo­graph of the central Jarash valley from 1953 showing terracing on east-facing slopes between the southern plateau and the El-Hammar plain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

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Figure 6.2.

Detailed aerial view of the terracing shown in Figure 6.1 showing the different terracing types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Figure 6.3.

Low-level oblique aerial photo­graph showing ancient terracing on an east-facing 30 per cent slope adjacent to the eastern watershed in the Majarr–Tannur valley to the east of Ain Nabi at an elevation of c. 900 m. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Figure 6.4.

Examples of ancient terracing from the upper eastern slopes of the Majarr–Tannur valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Figure 6.5.

An example of an ancient cross-wadi terrace in a small tributary in the Wadi Majarr valley to the south-west of Ain Nabi. . . . . . . . . . . . . 135

Figure 6.6.

Location of hypothetical barrage site near Birketein in the central Jarash valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Figure 6.7.

Example of a small, well-preserved runoff cistern on the slopes above the ancient site of Qasr Munye, immediately north of the Mukhayyam Suf settlement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Figure 6.8.

Site JWP162 showing a network of small rock-cut canals 0.15–0.2 m wide that carried runoff onto a quarried platform, and the water was then discharged into a cistern. . . . . . . . . . . . . . . . . . . . 138

Figure 6.9.

Examples of rock-cut conduit profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Figure 6.10. Evidence of conduit roofing of an aqueduct. . . . . . . . . . . . . . . . . . . . . . . . 140 Figure 6.11. Evidence of pick marks on conduit walls. . . . . . . . . . . . . . . . . . . . . . . . . . 141 Figure 6.12. Examples of pecked tool marks on conduit floors. . . . . . . . . . . . . . . . . . . 142 Figure 6.13. Examples of repeated plaster applications separated by carbonate sediment layers on conduit JW01. . . . . . . . . . . . . . . . . . . . 142 Figure 6.14. View of Ficus Springs locality, looking north, showing the location of the tunnel and JWP sites in the context of the local landscape. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Figure 6.15. Evidence of earlier steep wadi walls at Ficus Springs. . . . . . . . . . . . . . . . . 144 Figure 6.16. Views of the Ficus Springs site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Figure 6.17. View of the eastern side of the Ficus Springs locality showing springhead locations and the location and impact of a historic landslide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Figure 6.18. Examples of tunnel ‘windows’ on the east bank at Ficus Springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Figure 6.19. Ficus Springs, site JWP146, showing examples of a change in tunnel direction and uncut wall sections. . . . . . . . . . . . . . . . . 146 Figure 6.20. Ficus Springs, site JWP146, showing examples of tunnel damage caused by spring flow in the central tunnel section. . . . . . . . . . 147

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xvii Figure 6.21. Oblique aerial view of the tufa cascade in central Jarash showing the tunnel alignment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Figure 6.22. Tufa cascade tunnel profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Figure 6.23. Interior views of the tufa cascade tunnel. . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Figure 6.24. Examples of conduit blocks from a supply aqueduct on an old excavation dump located south of the St Theodore–Cathedral complex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Figure 6.25. Conduit blocks from aqueduct DW01 on the El-Hammar plain north of the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Figure 6.26. Examples of conduit blocks with a narrower specus from the El-Hammar plain north of the city. . . . . . . . . . . . . . . . . . . . . . . 150 Figure 6.27. Examples of conduit roofing types in the city area. . . . . . . . . . . . . . . . . . 151 Figure 6.28. Views of the substructio at site JWP111 carrying the aqueduct from Qairawan spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Figure 6.29. Examples of conduits bordered by dressed and partly dressed masonry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Figure 6.30. Varieties of ceramic pipe found in Gerasa by the Yale Mission in 1930. . 153 Figure 6.31. Examples of water supply pipes intra muros. . . . . . . . . . . . . . . . . . . . . . . . 154 Figure 6.32. Examples of lead piping in the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 Figure 6.33. Evidence of bridges crossing Wadi Jarash near the West Baths in a photo­graph by Guillaume-Rey in 1858. . . . . . . . . . . . . . . . . . . . . . . . 156 Figure 6.34. Evidence of a possible aqueduct bridge pier on the west bank of Wadi Jarash north of the West Baths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Figure 6.35. Hypothetical route of water conduit from Qairawan Cave spring to the West Baths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Figure 6.36. Examples of flow diversion devices at springheads. . . . . . . . . . . . . . . . . . 158 Figure 6.37. Examples of conduit type with a stepped specus sectional profile. . . . . . 160 Figure 6.38. Examples of pressure control devices built into pipelines in the city. . . 161 Figure 6.39. Aqueduct network sector map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Figure 6.40. Estimated peak flow rates for archaeo­logical sites on aqueduct JW01, assuming a water depth of 0.2 m in the canal. . . . . . . . . . . . . . . . 165 Figure 6.41. Types of conduit construction used in the upper Wadi Suf irrigation networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Figure 6.42. Map of the ancient aqueducts and their sources in the central Jarash valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Figure 6.43. Map of the Umm Qahara aqueduct network in the central Jarash valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

xviii Figure 6.44. Map showing the aqueducts supplied from Bisas er Rum and Es Soda springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Figure 6.45. Map of the DE02 aqueduct system from Tell Jarash North spring. . . . 171 Figure 6.46. Map of the ancient aqueduct systems probably sourced from Birketein. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 Figure 6.47. Map of aqueducts sourced from Esh Shawahid and nearby springs. . . . 172 Figure 6.48. Map showing the interpreted spatial relationship of aqueducts in the Birketein area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Figure 6.49. Diagram showing the interpreted disposition of the northern aqueducts approaching the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 Figure 6.50. Map of known and interpreted aqueduct conduits to the west of the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Figure 6.51. Map showing the disposition of extramural aqueduct systems sourced from west and east bank springs located in the city area. . . . . . 177 Figure 6.52. Map of the Qwndeit spring area showing the disposition of ancient aqueduct systems sourced from west bank springs. . . . . . . . . . . 177 Figure 6.53. The alignments of aqueducts JW04 and JW04a and their possible spring source on the western side of the Bab Amman mesa. . . . . . . . . . 178 Figure 6.54. Schematic diagram showing the interpreted alignments of aque­ ducts JW05, JW05a, and JW05b and the possible sources for aqueduct JW05. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Figure 6.55. Partially excavated arched structure adjacent to the South Bridge that may have been a spring house. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Figure 6.56. Details of the possible source for aqueduct JW05 south of the North Bridge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Figure 6.57. Map of the main aqueducts and ancient settlements in the southern Jarash valley between Bab Amman and the Wadi Tannur junction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Figure 6.58. Map of the local Haud Abu el Hajal aqueduct network in the context of the long-distance networks in the Jarash valley. . . . . . . . . . . 183 Figure 6.59. Map of the Jermish–Mesar Tokh valley aqueduct system. . . . . . . . . . . . 184 Figure 6.60. Map of the aqueduct networks in the Jarash–Zarqa River junction sector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Figure 6.61. Map of the layout of aqueducts supplied from Riyashi spring. . . . . . . . 185 Figure 6.62. Map of the aqueduct network supplied from Tannur spring. . . . . . . . . 185 Figure 6.63. Map of civic aqueducts supplying the city area in the Roman– Byzantine period. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

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xix Figure 6.64. Diagram synthesizing the location of the main irrigation aque­ ducts and aqueduct sources in the lower Jarash valley and Tannur valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Figure 6.65. Laminated freshwater carbonate preserved at site JWP128 on aqueduct JW01. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Figure 6.66. Chart of calibrated 14C AMS dates of organic materials from aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 Figure 6.67. Diagram of site JWP 128 on aqueduct JW01 showing a wellpreserved section through alternating layers of laminated carbonate sediment and plaster in the aqueduct specus. . . . . . . . . . . . . . 191 Figure 6.68. Aqueduct at site JWP128 showing evidence of canal bed scouring and a remnant of early carbonate sinter predating the crystallization of carbonate sinter S1. . . . . . . . . . . . . . . . . . . . . . . . . . 192 Figure 6.69. Aqueduct at site JWP128 showing evidence of a scoured channel infilled with P2 plaster cutting through carbonate sinter S1. . . . . . . . . . 192 Figure 6.70. Examples of possible early (pre-Roman) conduits in bedrock downstream of springs shown on satellite maps. . . . . . . . . . . . . . . . . . . . 194 Figure 7.1.

Map showing the location of reservoirs identified in the study. . . . . . . 198

Figure 7.2.

Map showing the location of the intramural reservoirs and storage basins recognized in the study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

Figure 7.3.

Images of Reservoir 1 in the city’s North-West Quarter. . . . . . . . . . . . . . 199

Figure 7.4.

Reservoir 1, showing the location of interpreted overflow canal and possible overflow basin in 2011. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

Figure 7.5.

Modern views of Reservoir 2 in the city’s South-West Quarter. . . . . . . 201

Figure 7.6.

The interpreted north reservoir in the city’s North-West Quarter. . . . . 201

Figure 7.7.

Aerial view of the interpreted central reservoir. . . . . . . . . . . . . . . . . . . . . 202

Figure 7.8.

Location of possible reservoir site in the city’s North-East Quarter. . . 203

Figure 7.9.

Location of possible reservoir sites associated with the northern aqueduct system to the city on 1953 aerial photo­graph. . . . . . . . . . . . . . 203

Figure 7.10. Plan of Birketein precinct showing main archaeo­logical features. . . . . 204 Figure 7.11. The ‘General Plan’ of Gerasa compiled by Charles Barry c. 1820, showing details of the Birketein reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . 205 Figure 7.12. Field sketch of Birketein reservoir drawn by Bankes in 1818. . . . . . . . . 205 Figure 7.13. Late nineteenth-century photo­graph of Birketein reservoir looking east. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Figure 7.14. 1930s photo­graphs of Birketein reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . 206 Figure 7.15. Plan of Birketein reservoir in its final form showing all twelve known outlets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

xx Figure 7.16. Diagrammatic representations of the interpreted construction stages of Birketein reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Figure 7.17. Birketein reservoir, showing elements of the water delivery system to the west wall of the northern compartment. . . . . . . . . . . . . . . . . . . . . 208 Figure 7.18. Example of water delivery mechanism to the slots at the foot of the north wall of the northern compartment of Birketein reservoir. . . 209 Figure 7.19. Water delivery system from spring located north of the Birketein reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Figure 7.20. Birketein reservoir, showing details of water outlet ‘E’. . . . . . . . . . . . . . . 210 Figure 7.21. Chart of calibrated 14C AMS dates of charcoal in mortar samples from Birketein reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Figure 7.22. Diagrams showing examples of Roman two-compartment reservoirs. 212 Figure 7.23. Plan of reservoirs identified near En Busat Zreq spring in the Wadi Suf valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Figure 7.24. The reservoir on the site of the Jarash University. . . . . . . . . . . . . . . . . . . 214 Figure 7.25. Spring basin on the upper east side of the city at site JWP138. . . . . . . . 214 Figure 7.26. Plan showing the location of basins identified in the area west of St Theodore’s Church. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Figure 7.27. The basin below ‘House VI’. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Figure 7.28. Views of ‘Cistern 1’ west of St Theodore’s Church. . . . . . . . . . . . . . . . . . 217 Figure 7.29. Sketch of the basins on the west bank of Wadi Jarash adjacent to aqueduct conduit JW05 based on 1918 aerial photo­graphy. . . . . . . . . . 218 Figure 7.30. View of the arched roof of the South Decumanus basin, looking south. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 Figure 7.31. Location of the west Artemis basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Figure 7.32. Ground views of the west Artemis basin. . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Figure 7.33. Cross-section showing the spatial relationship between the west Artemis basin and the Artemis upper terrace basin, looking north. . . . 220 Figure 7.34. Views of the North Theatre storage basin. . . . . . . . . . . . . . . . . . . . . . . . . . 221 Figure 7.35. The Placcus basin in the context of the Placcus Baths precinct. . . . . . . 222 Figure 7.36. Ground view of the Placcus Baths Basin. . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Figure 7.37. View from the north of the inside of the south wall of the Placcus basin showing key outlet points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Figure 7.38. Detailed view of the possible site of the supply aqueduct inlet in the west wall of the Placcus basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

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xxi Figure 7.39. Plan view of the Artemis lower terrace basin in the context of its supply aqueducts and the downstream castellum. . . . . . . . . . . . . . . . . . . . 225 Figure 7.40. The Artemis lower terrace basin. View looking south, showing the location of the outlets in the south wall. . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Figure 7.41. Profile view of Artemis lower terrace basin, looking west, showing the main architectural elements and the relationship with the later castellum to the south. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 Figure 7.42. Modern views of the Artemis forecourt basin. . . . . . . . . . . . . . . . . . . . . . 228 Figure 7.43. Examples of offtake basins beside aqueduct conduit JSE2 south of Jarash. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 Figure 7.44. Quarry/cave-basin at site JWP147 (site JHS786). . . . . . . . . . . . . . . . . . . 230 Figure 7.45. Plan showing the location of known and possible cisterns on the west side of the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Figure 7.46. Intramural cistern puteals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Figure 7.47. Examples of the necks in intramural cisterns. . . . . . . . . . . . . . . . . . . . . . . 233 Figure 7.48. Cubic cistern beneath Bishop Genesius Church. . . . . . . . . . . . . . . . . . . . 233 Figure 7.49. Views of Byzantine cisterns on Camp Hill. . . . . . . . . . . . . . . . . . . . . . . . . 234 Figure 7.50. Views of the barrel vaults beneath the cella and portico of the Temple of Artemis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 Figure 7.51. Underground views of the central low passage linking the two groups of vaulted chambers beneath the Artemis cella. . . . . . . . . . . 237 Figure 7.52. View of quarry-cistern at site JWP 109 from the east. . . . . . . . . . . . . . . 238 Figure 7.53. Views of quarry-cistern at site JWP 110 (locus 1). . . . . . . . . . . . . . . . . . 239 Figure 7.54. Quarry-cistern at site JWP 110 (locus 1). . . . . . . . . . . . . . . . . . . . . . . . . . 240 Figure 7.55. Bab Amman mesa showing the disposition of cisterns relative to the summit runoff field. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Figure 7.56. View of open cisterns on the summit of the Bab Amman mesa. . . . . . . 242 Figure 7.57. Vertical aerial view showing the disposition of cisterns on the summit of the Bab Amman mesa in the context of the interpreted quarrying area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 Figure 7.58. Oblique aerial view of the closed cistern at site JWP147 ( JHS site 767) at Bab Amman. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Figure 7.59. Views of the draw points of closed cisterns at Bab Amman. . . . . . . . . . 244 Figure 7.60. Examples of the cistern variant with a concave basin-shaped upper inlet shaft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 Figure 8.1.

Location of known intramural bathhouses and their precincts. . . . . . . 247

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List of Illustrations

Figure 8.2.

Location of extramural bathhouses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Figure 8.3.

Aerial view showing the relationship between the Placcus basin, the Placcus Baths, and the Glass Court Baths. . . . . . . . . . . . . . . . . . . . . . 249

Figure 8.4.

Oblique aerial photo­graph of the Central Baths showing the location of the pipe excavated in the South Decumanus in 1975 and possible pipeline alignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250

Figure 8.5.

Views of the suggested alternative water supply alignment to the Birketein Baths (and possibly also the theatre), seen from the east. . . . 251

Figure 8.6.

Sketch map showing the relationship between the two suggested sources of water to the Birketein Baths. . . . . . . . . . . . . . . . . . . . . . . . . . . . 252

Figure 8.7.

Aerial photo­graph showing the main archaeo­logical features in the vicinity of the El-Hammam spa. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253

Figure 8.8.

General views of the El-Hammam spa. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254

Figure 8.9.

Detailed views of the El-Hammam spa. . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

Figure 8.10. Map of the intramural fountain and ornamental basin installations referred to in the text. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 Figure 8.11. Map showing the location of fountain networks referred to in the text. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 Figure 8.12. The interpreted layout of the Cardo and North Decumanus fountain networks in the late second–early third centuries. . . . . . . . . . 261 Figure 8.13. Plan showing the possible supply to the Cardo fountain network and the disposition of known pipelines in the vicinity of the Cathedral Propylaeum and the Nymphaeum. . . . . . . . . . . . . . . . . . . . . . . 262 Figure 8.14. View of the gutter in the South Decumanus paving that carried the Cardo fountain network pipeline, looking south. . . . . . . . . . . . . . . . 263 Figure 8.15. The interpreted layout of the second phase of the Cardo fountain network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Figure 8.16. View of the gutters cut into road pavements carrying the second phase of the Cardo fountain network pipeline. . . . . . . . . . . . . . . . . . . . . 263 Figure 8.17. Aerial view of the western end of the upper terrace of the Artemis Temple (looking east) showing the location of the main basins on and adjacent to the terrace. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Figure 8.18. Views of the Artemis upper terrace basin. . . . . . . . . . . . . . . . . . . . . . . . . . 267 Figure 8.19. Photo­graphs of the cross-wall separating the two compartments of the Artemis upper terrace basin from 1976. . . . . . . . . . . . . . . . . . . . . . 268 Figure 8.20. The interpreted construction stages of the Artemis upper terrace basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

List of Illustrations

xxiii Figure 8.21. The Artemis upper terrace basin showing the relationship between the basin and the stage two north wall that acted as a substructio for the stage two aqueduct. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 Figure 8.22. Views of fill layers in the south-west corner of the Artemis upper terrace showing the location of 14C sample B-476377. . . . . . . . . . . . . . . 270 Figure 8.23. Plan of the Qairawan precinct showing the location of the Qairawan spring basin and the approximate precinct boundary. . . . . . 271 Figure 8.24. The frontal spouts in the Nymphaeum parapet wall, showing the anthropoid features of carved spout 5 and the unique piscine decoration of the basin below it, compared with the carved features for spouts 2 and 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Figure 8.25. Main agricultural zones, irrigation aqueducts, and their sources in the central Jarash valley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 Figure 8.26. An estimate of the distribution of the main intramural farming areas on the west side of the city at the end of the second century. . . . . 277 Figure 9.1.

A map showing the location of intramural springs supplying aqueducts and the elevations of the springs and entry points of extramural aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286

Figure 9.2.

A map showing the relationship between alignments of conduit JW01f and the south-west aqueduct postulated by Stott and others 2018. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286

Figure 9.3.

Views of an early aqueduct passing through the west wall of the city in City Walls project trench 500. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288

Figure 9.4.

A diagrammatical interpretation of the phases of aqueduct conduits constructed in the vicinity of the Artemis upper terrace basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

Figure 9.5.

Locations of recorded aqueduct sites in the city’s North-West Quarter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291

Figure 9.6.

Views of the alignment of a major aqueduct within the NorthWest Quarter of the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292

Figure 9.7.

The alignment of aqueducts SW02a/DW01 in the North-West Quarter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

Figure 9.8.

An aqueduct block exposed in the west wall of the so-called ­basilica (‘site 5’). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294

Figure 9.9.

The alignment of the Qairawan aqueduct ( JE02) in the vicinity of the Large East Baths showing the deviation in the alignment of the second-century aqueduct to connect with the earlier aqueduct alignment from Qairawan at a lower elevation. . . . . . . . . . . . . . . . . . . . . 295

Figure 9.10. The alignments of Qairawan aqueduct JE02 in the context of the eastern side of the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

xxiv Figure 9.11. Sketch showing the relationship between the second-century aqueduct from Qairawan spring and an earlier alignment at a lower elevation based on an interpretation of a 1918 aerial photo­graph. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 Figure 9.12. Evidence of a Corinthian building on the east bank of Wadi Jarash. . . 297 Figure 9.13. The general disposition of conduits sourced from Qairawan Cave spring and interpreted alignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Figure 9.14. A five-metre-long section of lead pipeline exposed in an excavation beside the southern colonnade, South Decumanus. . . . . . . . 298 Figure 9.15. A 1930s photo­graph of a ceramic pipeline and in-line sediment basin laid on the floor of an earlier basin in Room R-28 west of St Theodore’s Church. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Figure 9.16. Plan showing the distribution of Roman–Byzantine castella. . . . . . . . . 300 Figure 9.17. An example of a first-order drain carrying roof runoff to cisterns in the Genesius Church. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Figure 9.18. Aerial view from the east showing the drainage arrangement that carried runoff from the Antonine lower terrace of the Temple of Artemis to the Cardo main drain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Figure 9.19. Views of the drain entrances that carried runoff from the Antonine lower terrace of the Temple of Artemis to the Cardo sub-street drain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Figure 9.20. Views of conduits in the area west of St Theodore’s Church. . . . . . . . . 305 Figure 9.21. Evidence of possible runoff control from the Artemis upper terrace. . . 306 Figure 9.22. Examples of gutters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 Figure 9.23. Examples of street gutter drains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 Figure 9.24. Aerial photo­graph showing the alignment of the thirdand fourth-order drains beneath the Oval Piazza. . . . . . . . . . . . . . . . . . . 308 Figure 9.25. Plan of the known third- and fourth-order drain network on the west side of the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 Figure 9.26. Aerial view of the North Decumanus drain alignment east of the North Tetrapylon, looking north. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 Figure 9.27. Cross-sections through fourth-order drains. . . . . . . . . . . . . . . . . . . . . . . . 311 Figure 9.28. Photo­graphs showing the construction detail of fourth-order drains. . 311 Figure 9.29. View of the primary drain emerging from below the South Gate, looking south-west. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 Figure 9.30. Views of the ‘sewer’ located adjacent to ‘Cistern 1’, west of St Theodore’s Church. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

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xxv Figure 10.1. Map showing the location of intramural reservoirs, storage basins, and castella supplied by spring-fed aqueducts. . . . . . . . . . . . . . . . . . . . . . 318 Figure 10.2. Map of intramural aqueduct-fed water distribution and storage components existing around ad 106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 Figure 10.3. Plan of intramural aqueduct-fed water distribution and storage components existing around ad 150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Figure 10.4. Map of intramural aqueduct-fed water distribution and storage components existing around ad 200. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 Figure 10.5. Map of intramural aqueduct-fed water distribution and storage components existing around the fourth century. . . . . . . . . . . . . . . . . . . . 324 Figure 10.6. Map of intramural aqueduct-fed water distribution and storage components existing around the sixth century. . . . . . . . . . . . . . . . . . . . . . 326 Figure 10.7. Map of intramural aqueduct-fed water distribution and storage com­ ponents existing just prior to the mid-eighth-century earthquakes. . . . . . 32 Figure D.1. Chart of calibrated 14C AMS dates of organic materials. . . . . . . . . . . . . 353 Figure F.1.

Views of Maghasil spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357

Figure F.2.

Views of Mansura spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358

Figure F.3.

Muqbila spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358

Figure F.4.

Fauwara spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359

Figure F.5.

Nabhan spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360

Figure F.6.

Umm Qahara spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360

Figure F.7.

Aerial view of the En Busat Zreq spring locality showing the relative locations of the current and historical spring sites. . . . . . . . . . . 361

Figure F.8.

Esh Shawahid spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362

Figure F.9.

Bisas er Rum spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363

Figure F.10. Plan of Birketein reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 Figure F.11. Birketein South spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 Figure F.12. Birketein West spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 Figure F.13. Es Soda spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Figure F.14. Deir el Liyat spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Figure F.15. Early nineteenth-century plans of the Qairawan spring area. . . . . . . . . 368 Figure F.16. Qairawan pool installation in 2013. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 Figure F.17. Early twentieth-century photographs of Qairawan spring showing the main features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 Figure F.18. Photographs of the reconstructed Qairawan basin in 1944. . . . . . . . . . 370

xxvi Figure F.19. Evidence showing that the masonry wall at the north-western end of the Qairawan basin formed part of the twentieth-century basin reconstruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 Figure F.20. Evidence of curved erosion lines etched into the surface of the monumental wall at Qairawan spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 Figure F.21. Qairawan Cave spring showing spring outlets, aqueducts, and concrete ‘façade’. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372 Figure F.22. Modern views of lower cascade spring site. . . . . . . . . . . . . . . . . . . . . . . . . 373 Figure F.23. Lower cascade spring site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 Figure F.24. Historical photographs of the eastern spring site. . . . . . . . . . . . . . . . . . . 374 Figure F.25. A modern view of the spring at site JWP138, looking north-east, showing the interpreted basin walls and location of the delivery canal from the spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 Figure F.26. The site of the cascade spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 Figure F.27. Views of the South Bridge spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 Figure F.28. A 1926 aerial view of the Bab Amman mesa showing the location of Qwndeit spring in the context of the alignments of ancient aqueducts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 Figure F.29. Kokosi cascade spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Figure F.30. General view of the Ficus Springs locality, looking north, showing the location of the main spring outlets on both wadi banks. . . . . . . . . . 378 Figure F.31. Spring outlets on the east bank of Ficus Springs at site JWP 146. . . . . 379 Figure F.32. Ficus Springs at site JWP140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379 Figure F.33. An overview of the Shallal East spring sites site, looking east. . . . . . . . . 380 Figure F.34. Main features at sites JWP173 and 174. . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 Figure F.35. Overview of the spring site showing the main features. . . . . . . . . . . . . . 381 Figure F.36. Specific features at the spring site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381 Figure F.37. Riyashi springs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382 Figure F.38. Modern aerial overview of the Tannur spring sites. . . . . . . . . . . . . . . . . . 382 Figure F.39. Ground views of Tannur spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 Figure F.40. The Tannur spring precinct, showing the disposition of masonry ruins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 Figure F.41. Modern aerial overview of the Ain Nabi springs, looking south . . . . . . 384 Figure F.42. Detailed aerial view showing the disposition of the Ain Nabi spring outlets and ancient canals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

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xxvii Figure G.1. View along aqueduct SUDW02 at site JWP120, looking west. . . . . . . 388 Figure G.2. Aerial view of SUFW02 aqueduct conduits near site JWP117. . . . . . . 388 Figure G.3. Ground views of SUFW02 rock-cut conduits near site JWP117 on the alignment of aqueduct SUFW02 at site JWP117. . . . . . . . . . . . 389 Figure G.4. Yale Mission plan showing the position of in situ sections of aqueduct DW01 in the context of other aqueducts and JWP site locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 Figure G.5. DW01 conduit blocks at site JWP105. . . . . . . . . . . . . . . . . . . . . . . . . . . . 390 Figure G.6. Detailed views of plastered conduit block with remnant carbonate deposits at site JHS750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390 Figure G.7. Aqueduct conduit blocks from site JWP106 relocated to the Birketein reservoir precinct in 2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 Figure G.8. Aqueduct DW01 at site JWP143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 Figure G.9. The interpreted alignment of the North Gate aqueduct DW01c. . . . . 392 Figure G.10. Conduit block at site JWP107. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 Figure G.11. The evidence of aqueduct alignments at site JHS485. . . . . . . . . . . . . . . . 394 Figure G.12. The merged alignments of DW04 and DW05 at site JHS469. . . . . . . . 395 Figure G.13. Aqueduct conduit DW05 at site JWP144. . . . . . . . . . . . . . . . . . . . . . . . . 395 Figure G.14. Views of aqueduct JSW01 at site JWP175. . . . . . . . . . . . . . . . . . . . . . . . . 396 Figure G.15. Rock-cut section of aqueduct JSW02 recorded at site JWP176a. . . . . 397 Figure G.16. Site JWP155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 Figure G.17. Site JWP115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 Figure G.18. Site JWP112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 Figure G.19. Site JWP114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 Figure G.20. Aqueduct chute at site JWP127. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 Figure G.21. The exposure of aqueduct JW01 in the road cutting at site JWP128. . . . 400 Figure G.22. Detailed view of aqueduct after cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . 401 Figure G.23. The aqueduct at site JHS143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 Figure G.24. Aerial view of site JWP153, looking west. . . . . . . . . . . . . . . . . . . . . . . . . . 402 Figure G.25. View of canal alignment at site JWP153. . . . . . . . . . . . . . . . . . . . . . . . . . . 403 Figure G.26. Diagram showing the interpretation of aqueduct alignments attributed to aqueducts JW03 and JW05 at site JWP147. . . . . . . . . . . . 403 Figure G.27. Views of the main aqueduct conduits at site JWP147, looking south. 404

xxviii Figure G.28. Views of aqueduct JW04. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 Figure G.29. Aerial view of the alignments of aqueducts JW04 and JW04a. . . . . . . . 406 Figure G.30. Aqueduct JW04a. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407 Figure G.31. Aqueduct JW05 at site JWP147a. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407 Figure G.32. Details of the later tomb dromos cut through aqueduct JW05 at site JWP147a. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Figure G.33. 2008 Aerial view of South-West Gate showing the location of aqueduct JW07 at site JWP192. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Figure G.34. Views of aqueduct JW07 at site JWP192. . . . . . . . . . . . . . . . . . . . . . . . . . 409 Figure G.35. Views of aqueduct JW08 at site JWP192, looking west. . . . . . . . . . . . . 410 Figure G.36. Aqueduct SW01 overview map, showing the location of the Esh Shawahid source spring and site JWP124. . . . . . . . . . . . . . . . 411 Figure G.37. The aqueduct recorded at site JWP124, looking north-west. . . . . . . . . 411 Figure G.38. An aerial view of aqueduct SW02 at site JWP164 showing the main features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 Figure G.39. Site JWP165. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 Figure G.40. Aqueduct JW02a sites near the city. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 Figure G.41. Aqueduct SW02a at coordinates 35.89208° E, 32.29965° N. . . . . . . . . 414 Figure G.42. Aqueduct DE01. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 Figure G.43. Alignment of part of aqueduct DE01 and site JHS238 on an aerial photo­graph taken in 1926. . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 Figure G.44. Examples of exposures of aqueduct DE01. . . . . . . . . . . . . . . . . . . . . . . . . 416 Figure G.45. Aerial view of the tunnel carrying aqueduct JE01 from the lower cascade spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 Figure G.46. View of the tunnel at site JWP156, looking north (upstream), showing the higher elevation tunnel floor and the lower elevation trapezoid canal specus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 Figure G.47. Aqueduct JE01 at site JWP169, looking downstream, showing details of the three specus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 Figure G.48. Comparative views of site JWP111 in 2013 and 2015. . . . . . . . . . . . . . . 418 Figure G.49. Evidence of the construction materials in the substructio. . . . . . . . . . . . 418 Figure G.50. Details of the aqueduct channel at site JWP111. . . . . . . . . . . . . . . . . . . . 419 Figure G.51. View of spring outlets and interpreted concrete cover to aqueduct JE02. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419 Figure G.52. Views of the aqueduct channel outside the cave. . . . . . . . . . . . . . . . . . . . 420

L ist of Illustrations

List of Illustrations

xxix Figure G.53. Aqueducts sourced from Qairawan Cave spring. . . . . . . . . . . . . . . . . . . . 421 Figure G.54. Details of aqueduct JE04. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 Figure G.55. 1903 photo­graph showing the half-tunnel carrying aqueduct JE04a running north from Qairawan Cave spring along the foot of the cliff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 Figure G.56. Section of the half-tunnel that carried aqueduct JE04a to the north of Qairawan Cave spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 Figure G.57. Views of tunnel aqueduct and surface rock-cut canals at the southern end of site JWP146. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 Figure G.58. View of the spring tunnel and aqueduct canal at the northern end of site JWP146. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 Figure G.59. Views of the rock-cut canals at the southern end of site JWP146. . . . . 424 Figure G.60. Evidence of early rock-cut canals truncated by later wadi incision at site JWP146. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 Figure G.61. Evidence of aqueduct JSE01 in the Shallal locality. . . . . . . . . . . . . . . . . . 425 Figure G.62. Views of ancient canal remnants at site JWP121. . . . . . . . . . . . . . . . . . . 426 Figure G.63. Views of sites along aqueduct SE05 at site JWP125. . . . . . . . . . . . . . . . . 426 Figure G.64. Aqueduct SE06 at site JWP183. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 Figure G.65. Aqueduct SE06 at site JWP167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 Figure G.66. Aqueduct TE02 at site JWP135. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 Figure G.67. Aqueduct RE01 at site JWP187. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 Figure G.68. Aqueduct TE01 at Tannur spring (site JWP135). . . . . . . . . . . . . . . . . . . 429 Figure G.69. Aqueduct TE01 at site JWP135. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 Figure G.70. Views of conduit TE01 from Tannur spring at site JWP179. . . . . . . . . 430 Figure I.1.

1930s photo­graph of the parapet wall at Qairawan spring. . . . . . . . . . . 436

Figure I.2.

View of the restored Roman parapet wall inside the modern water treatment facility, looking north-east. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436

Figure I.3.

Niche fountains 2a and 2b flanking the staircase to the Odeum portico. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437

Figure I.4.

The North Tetrapylon fountains 3a to 3d. . . . . . . . . . . . . . . . . . . . . . . . . . 438

Figure I.5.

Close-up views of each fountain installation. . . . . . . . . . . . . . . . . . . . . . . 439

Figure I.6.

Evidence of a pressure pipe at the eastern end of the Artemis upper terrace basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439

Figure I.7.

Location plan for fountains 5a to 5f in the vicinity of the Eastern Propylaeum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440

xxx

L ist of Illustrations

Figure I.8.

Views of fountains 5a–5d. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441

Figure I.9.

Views of two pipelines that crossed the Cardo to supply fountains 5c and 5d adjacent to the Eastern Propylaeum. . . . . . . . . . . . . . . . . . . . . 442

Figure I.10. The monumental façade fountain on the west side of the Cardo. . . . . . 443 Figure I.11. View of the fountain basin, looking south. . . . . . . . . . . . . . . . . . . . . . . . . 444 Figure I.12. Details of the frontal spouts set in the parapet wall of the Nymphaeum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 Figure I.13. Views of the large frontal outlet located at the south-east corner of the Nymphaeum basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446 Figure I.14. Fountain 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 Figure I.15. Fountain 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 Figure I.16. Fountain 8 lacus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448 Figure I.17. Fountain 8 viewed from the south. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 Figure I.18. Views of the Arabic inscription cut into the face of the pedestal base. . . 449 Figure I.19. Fountain 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 Figure I.20. Fountain 9 lacus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 Figure I.21. Fountain 10, viewed from the east. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 Figure I.22. View of the rectangular base of fountain 10 showing the location of spouts and evidence of wear from water jars beneath the northern spout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 Figure I.23. Fountain 11 installation in the centre of the Macellum. . . . . . . . . . . . . . 452 Figure I.24. Close-up of the centrally placed fountain base. . . . . . . . . . . . . . . . . . . . . 452 Figure I.25. The author’s hypothetical reconstruction, showing the labrum currently in front of the monumental façade fountain (fountain 6) placed on the base of the Macellum fountain. . . . . . . . . . . . . . . . . . . . 452 Figure I.26. Fountain 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 Figure I.27. Fountain 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454 Figure I.28. Fountain 14. View of the inverted base in a secondary context on the Artemis lower terrace in 2018. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454 Figure I.29. Fountain 15 pedestal at the south-west corner of the South Tetrakionion plaza. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 Figure I.30. Fountain 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 Figure I.31. Fountains 17a and 17b in the atrium of St Theodore’s Church. . . . . . . 457 Figure I.32. Fountain 17a. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458 Figure I.33. Fountain 17b. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458

List of Illustrations

xxxi Figure I.34. Fountain 18. Aerial view of Artemis forecourt basin with water channels highlighted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 Figure I.35. Ground views of the fountain 18 site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 Figure I.36. Fountain 19. View of the plastered basin and possible fountain installation in the centre of the Oval Piazza, looking west. . . . . . . . . . . 460 Figure I.37. Fountain 20. The modern view of Fountain Court, looking east, showing the fountain installation in the centre of the Cathedral atrium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460 Figure I.38. View of the eastern wall of the fountain in Fountain Court when excavated showing missing elements of the installation. . . . . . . . . . . . . . 461 Figure I.39. Details of water supply arrangement to the fountain in Fountain Court, showing the main features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 Figure I.40. Close-up of the water supply inlet pipe in the centre of the basin of fountain 20, as seen in 2011. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 Figure I.41. View of the recess in the north-west corner of Fountain Court that contained a lead pipe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 Figure I.42. Airholes in the pipeline supplying fountain in Fountain Court. . . . . . . 464 Figure I.43. The possible fountain 21 installation in the Synagogue Church. . . . . . 465 Figure I.44. Fountain 22 beside the Church of Bishop Genesius. . . . . . . . . . . . . . . . . 466 Figure I.45. Site of fountain 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466 Figure I.46. Detailed modern view of fountain 24 adjacent to the eastern side of the southern façade of the North Gate. . . . . . . . . . . . . . . . . . . . . . . . . . 467 Figure I.47. Modern aerial view showing the interpreted alignment of the aqueduct DW01c to fountain 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467 Figure I.48. Fountain 25, Birketein reservoir. Photo­graph of the lion’s head outlet of fountain 25 in the south wall of the southern compartment. 468 Figure I.49. West–east cross-section through Birketein reservoir area showing the location of lion’s head spout of fountain 25 near the southwest corner of southern reservoir compartment. . . . . . . . . . . . . . . . . . . . 468 Figure I.50. Fountain 26. View of Qairawan Cave spring from the west showing the location of the natural fountain cascade at the contact between Jarash Conglomerate and Na’ur limestone. . . . . . . . . . 469 Figure I.51. Fountain 27. General view of the installation at site JWP146 on the east bank of Wadi Jarash at Ficus Springs. . . . . . . . . . . . . . . . . . . . 470 Figure I.52. Fountain 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471 Figure I.53. Fountain 28 site viewed from the east in 2014. . . . . . . . . . . . . . . . . . . . . 471 Figure I.54. Detailed views of the fountain 28 installation at site JWP140 in 2014. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472

xxxii

List of Illustrations

Figure I.55. Fountain 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472 Figure I.56. Fountain 30 in the context of other water-related features on the west bank of Wadi Jarash at Ficus Springs (before excavation), viewed from the east. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 Figure I.57. Detailed view of fountain 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475 Figure I.58. Fountain 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476 Figure I.59. Fountain 32. General view of the complex of water-related installations on the eastern wadi bank at JWP site 173, as seen from the Shallal waterfall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476 Figure I.60. View of the components of the fountain cascades above the spring source for a Roman aqueduct. . . . . . . . . . . . . . . . . . . . . . . . . . . 477 Figure I.61. Fountain 33. Details of the reconstructed overflow basin and cascade at the eastern outlet at Tannur spring, viewed from the west. . 477 Figure I.62. Views of the Tannur spring cascade showing the outlet from the basin to the cascade apron. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478 Figure I.63. Historical photo­graphs of the site of fountain 34. . . . . . . . . . . . . . . . . . . 479 Figure I.64. A modern view of the fountain 34 installation. . . . . . . . . . . . . . . . . . . . . 479 Figure I.65. Fountain 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 Figure I.66. Hypothetical reconstruction of the fountain 35 installation. . . . . . . . . 480 Figure I.67. The pipeline across the Cardo that supplied fountain 35. . . . . . . . . . . . 481 Figure I.68. Fountain 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 Figure J.1.

View of Castellum 1 and the adjacent Artemis lower terrace basin that supplied it from the east. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483

Figure J.2.

View of Castellum 1 from the north, showing the supply canal from the Artemis lower terrace basin, the remnant floor of the castellum, and the three primary castellum outlets. . . . . . . . . . . . . . . . . . . 483

Figure J.3.

Detailed view of the outside of the southern wall of the watermill chamber from the south, showing evidence of channelling in the wall to accommodate pipelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484

Figure J.4.

Details of the castellum outlets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485

Figure J.5.

1931 Photo­graph of Castellum 2 in Room B-76, west of St Theodore’s Church, looking north. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486

Figure J.6.

Plan showing the location of the castellum and outlets. . . . . . . . . . . . . . 486

Figure J.7.

View of the Room A-40/42 basin from the north-east showing the large inlet from Castellum 3 entering the Room A-42 basin. . . . . . 487

Figure J.8.

Castellum 4. Aerial view of the site of Castellum 4 taken in 2008 showing remnants of the northern and eastern walls. . . . . . . . . . . . . . . . 487

List of Illustrations

xxxiii Figure J.9.

Plan views of Castellum 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488

Figure J.10. Castellum 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 Figure J.11. Plan showing the location of Castellum 6 in the context of the alignment of the Qairawan aqueduct and ‘Room 13’. . . . . . . . . . 490

Tables Table 2.1. Archaeo­logical chrono­logical chart.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 2.2. Water management-related studies in the Decapolis. . . . . . . . . . . . . . . . . . . . . 10 Table 2.3. Table of ground surveys conducted wholly or partially within the study area.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 2.4. List of town plans of Gerasa drawn by nineteenth-century visitors. . . . . . . . 15 Table 3.1. Strati­graphic classifications within the Jarash valley watershed.. . . . . . . . . . . 39 Table 3.2. Catchment area statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Table 3.3. Valley floor gradient statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Table 3.4. Spring location statistics in the context of the watersheds. . . . . . . . . . . . . . . . 63 Table 3.5. Spring classification according to discharge rates. . . . . . . . . . . . . . . . . . . . . . . . 64 Table 3.6. Published spring flow rates.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Table 3.7. Spring discharge categorization matrix.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Table 3.8. Relative discharge strength statistics (modern springs) in the context of aquifer source.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Table 3.9. Relative discharge strength statistics (relict springs) in the context of aquifer source.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Table 3.10. List of earthquakes with Mw >5.0 within a 150 km radius of Gerasa between 33 bc and ad 750.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Table 4.1. Summary of archaeo­logical (excavation) evidence from the Hellenistic period in Jarash.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Table 4.2. Main public buildings constructed in Gerasa ad 50–100.. . . . . . . . . . . . . . 103 Table 4.3. List of Christian churches in Gerasa. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Table 5.1. Modern rainfall statistics for weather stations within and adjacent to the study area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Table 5.2. Dates of main structures at Birketein.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Table 6.1. Gradients calculated for Gerasa aqueduct JW01. . . . . . . . . . . . . . . . . . . . . . . 164 Table 6.2. Calculated hydraulic parameters for aqueducts JW01, DW01, and JE02. . . 164 Table 7.1. Summary of the main intramural water storage installations.. . . . . . . . . . . . 196

xxxiv Table 7.2. Summary of main extramural water storage installations. . . . . . . . . . . . . . . . 196 Table 7.3. Summary of the interpreted construction stages of Birketein reservoir.. . . 208 Table 7.4. Public monuments and spaces on the west side of Gerasa showing estimated runoff volumes using a runoff coefficient (RC) of 80 per cent.. . 236 Table 7.5. Details of open-type cisterns recorded by JWP.. . . . . . . . . . . . . . . . . . . . . . . . 241 Table 8.1. Estimated maximum flow rates for fountains 6 and 20.. . . . . . . . . . . . . . . . . 265 Table 9.1. Drain hierarchical categories.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 Table 10.1. Area of the city potentially supplied by individual aqueducts in the northern aqueduct network.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Table A.1. List of early European visits to Jarash who recorded water features: 1812–1875. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Table B1. Catalogue of pre-WW2 aerial photo­graphs covering all or part of study area.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Table C1. Jarash Water Project site database.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Table D1. List of 14C AMS dates.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 Table E.1. Summary of seismic damage at Gerasa. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Table F.1. Important springs: statistical summary.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 Table G.1. Aqueduct statistics.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Table G.2. List of aqueducts recorded in the field.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 Table H.1. List of known bathhouses and relevant biblio­graphic references.. . . . . . . . . 431 Table I.1. List of masonry fountains identified in the study together with their information sources.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 Table I.2. List of natural fountains identified in the study together with information sources.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434

List of Illustrations

Author’s Preface

T

he inspiration for the Jarash Water Project and for this book came, firstly, from ancient water-related installations recorded by the Jarash Hinterland Survey and, secondly, the need to understand the city’s well-attested peak period of urban growth in the Roman–Umayyad period in the context of the water management system. Archaeo­logical research spanning more than a century has resulted in a reasonable understanding of the city’s urban history but without a commensurate understanding of the fundamentally important — but largely extramural — water supply and transport system that sustained the city and its agricultural hinterland. This book attempts to fill this knowledge gap by providing answers to fundamental questions in relation to water sources, supply networks, and use. As research progressed, it became increasingly interdisciplinary in scope, which allowed the results to be seen in broader physio­graphical and historical contexts. It is based on seven years of core doctoral research and observations made over a longer period. Like the Jarash Hinterland Survey that preceded it, the activities of the Jarash Water Project have proved timely in providing a permanent record of sites that are rapidly falling victim to the modern development occurring within and adjacent to the ancient city.

Acknowledgements I am indebted to Emeritus Professor David Kennedy for setting me on the path of this research and for his enthusiasm and encouragement since then. The topic was inspired by my participation in the Jarash Hinterland Survey co-directed by David Kennedy and Fiona Baker, and their generosity in making the survey results available is gratefully acknowledged. Likewise, the availability of thousands of aerial photo­graphs taken by many photo­graphers under the auspices of the Aerial Photo­graphic Archive for Archaeo­logy in the Middle East (APAAME) since 1998, under the co-directorship of David Kennedy and Robert Bewley, has been of immense benefit in the completion of this research and is gratefully acknowledged. The field research was partially funded by the University of Western Australia, including two Rodney R. T. Prider Travel Scholarships. The assistance of the director and staff of the Jordanian Department of Antiquities in the facilitation of fieldwork and the issuance of permits is gratefully acknowledged.

Abbreviations Used in the Text AASOR ACOR AdZ ALS AMS AP APAAME ASOR bp d. DAI DOA DHC DST DWhG EAMENA GIS GPS HAS JHS JNWQ JWP LHS MEC PEF RIBA UCL UWA WW1 WW2 YUAG

Annual of the American Schools of Oriental Research American Center of Oriental Research Archiv der Zentrale (DAI) Airborne laser scanning Accelerator Mass Spectrometry (technique to measure radio­carbon in samples) Aerial photo­graph Aerial Photo­graphic Archive for Archaeo­logy in the Middle East American Schools of Oriental Research Before present (1950) Died Deutsches Archäo­logisches Institut Department of Antiquities of Jordan Dorset History Centre, Dorchester, UK Dead Sea Transform Deutschen Wasserhistorischen Gesellschaft Endangered Archaeo­logy in the Middle East and North Africa Geo­graphic Information System Global positioning system Hunting Aerial Surveys Jarash Hinterland Survey Jerash Northwest Quarter Project Units of Measurement Jarash Water Project cm centimetre Left hand side km kilometre Middle East Centre, St Anthony’s College, Oxford L litre Palestine Exploration Fund m metre Royal Institute of British Architects, London, UK mL millilitre University College London mm millimetre The University of Western Australia M million First World War, 1914–1918 Ma million years Second World War, 1939–1945 s second Yale University Art Gallery ka thousand years

Glossary Alluvium Unconsolidated sedimentary material deposited in a river or wadi by a stream of running water. Aqueduct An artificial conduit used to carry water from a source. Calcretization The precipitation of calcium carbonate via chemical processes in the regolith that indurates the unconsolidated material into hard, limestone-like rock. Canal An artificial watercourse or extensively modified natural channel used for the transport and/or control and diversion of water for drainage or irrigation. Carbon 14 A radioactive isotope of carbon with a true half-life of 5730 years. Cement A building material made by grinding calcined limestone and clay to a fine powder, which can be mixed with water and poured to set as a solid mass, or it is used as an ingredient in making mortar or concrete. Cistern A rock-cut subterranean or part subterranean structure with no outlet used to store rainwater. It may be a modification of a natural cave or solution feature. It does not connect to the water table. Colluvium Unconsolidated or weakly consolidated, heterogeneous, and incoherent mass of soil material and/or rock fragments deposited by rainwash, sheet-wash, or downslope creep that collects at the foot of slopes or hillsides (adapted from USGS). Concrete A term used to define a mortar containing coarse aggregate, stones, or rubble used to bind structures, construct stand-alone walls, or as a foundation for plaster. Confined aquifer An aquifer bound by impermeable horizons above and below, causing it to be under pressure. Debris flow An ill-sorted water-laden mass of rock, boulders, gravel, and soil that moves downslope under gravity. Knickpoint A sharp change in the valley floor gradient as a result of rejuvenated erosion following a change in base level. Locus A portion of an archaeo­logical site containing a feature and spatially separate from other contexts and features. Mortar Mixtures obtained by combining a binder, water, and sand in suitable proportions used to bond diverse types of stone materials or bricks in ancient and modern masonry.

xxxviii

Glossary

Orthorectification In remote sensing, the use of elevation data to correct terrain distortion in imagery. Panchromatic image In remote sensing, a single band image generally displayed as shades of grey. Plaster A mixture of lime or gypsum, sand, and water, sometimes with other additives applied to the surface of walls of buildings and hydraulic installations such as aqueducts, cisterns, tanks, and reservoirs. Radio­carbon dating A technique that can provide the age of (mainly organic) materials through the determination of the amount of remnant Carbon 14 present. Regolith Unconsolidated material lying on solid bedrock; it includes alluvium, colluvium, soil, and weathered bedrock. Relict An ancient landform or feature that has escaped destruction. Relief The variation in the physical shape of the earth’s surface. Reservoir A rock-cut or masonry structure, typically supraterranean or part subterranean — with an inlet and outlet — used to store water, typically from a spring or wadi source. Speleothem A structure formed in a cave by the deposition of minerals (mainly calcium carbonate) from water. Spolia The reuse of earlier building material or architectural piece on new monuments. Transmissivity A measure of groundwater movement through an aquifer. Tufa Freshwater calcium carbonate precipitated from cool or near ambient temperature spring waters. Travertine Freshwater calcium carbonate precipitated from thermal-hydrothermal waters. Unconfined aquifer An aquifer that is not confined by pressure. Water channel A naturally occurring feature that carries water. Water table The upper unconfined surface of groundwater. Well An artificial shaft or hole in the ground that connects with the water table.

Chapter 1

Introduction tains evidence of bathhouses and fountains that required a substantial water supply and must have had a water management system sophisticated enough to cater for this need combined with the domestic needs of its population and the water demands of its rural hinterland. However, despite over one hundred years of archaeo­logical study, this water management system — which is taken to embrace the water sources, the water transport, storage, and distribution networks, and the social organization that controlled and managed Figure 1.1. Gerasa in the context of the other cities of the Decapolis and modern political boundaries. it — has received scant attenDrawing N. Ellis. Unless otherwise indicated, all figures are copyright of Jarash Water Project. tion from scholars until recently. 4 The author established the The provincial city of Gerasa (modern Jarash) in northJarash Water Project ( JWP) in 2012 with the aim of ern Jordan has been the subject of historical and archaeo­ resolving this and related research questions through logical research since its rediscovery by the German a comprehensive and critical analysis of the evidence. explorer Ulrich Seetzen in 1806.1 Gerasa was one of the A  study period closing with the end of the Umayyad 2 cities of the Decapolis (Fig. 1.1). Archaeo­logical excavaperiod in ad  750 was selected, as this also roughly tions confirm the creation of a flourishing Roman procoincides with regionally significant earthquake events vincial city in the first and second centuries ad, on the that severely impacted the city and its infrastructure.5 site of a poorly understood Hellenistic settlement established by the second century bc, and contemporary litconducted on the site in the1920s–early 1930s. For summaries of erary sources imply that an urban settlement continued subsequent archaeo­logical activities on the site by various teams, see 3 on the site until at least the tenth century. The city con1 

Seetzen 1810, 32–34. The Decapolis is the name given to a group or league of Hellenistic cities with generally contiguous territories established from colonies founded at various times under Ptolemaic and Seleucid hegemony in the third and second centuries bc in an area known as Coele Syria. Today, the cities lie in northern Jordan and Syria apart from Scythopolis, which lies west of the Jordan River. For the definition of the term Decapolis, see Lichtenberger 2003, 6–20. For a discussion on the origins of the Decapolis, see Graf 1992 and Cimadomo 2019. 3  There is a substantial archaeo­logical corpus covering Gerasa in the Hellenistic and Roman–Byzantine periods. Kraeling (1938a) synthesized the results of archaeo­logical excavations and clearances 2 

Raja 2012, 137–75; Lichtenberger and Raja 2020, especially 7–31. Walmsley (2011, 142) quoted Arabic ninth- and tenth-century sources that referred to Jarash as a district capital in the Jund alUrdunn. This implies that Jarash was an Islamic urban centre until at least the early tenth century. He also suggested that ‘Phase 2 [of the so-called Congregational Mosque] ended sometime in the late tenth/mid-eleventh centuries ad’ (Walmsley 2018, 250). 4  Water-related publications prior to the JWP included studies of bathhouses and fountains, and speculation as to the water sources. On bathhouses, see Lepaon 2008; 2012a; 2012b. On urban fountains, see Seigne 2008. On water sources, see Seigne 2008; Lichtenberger and Raja 2016a. 5  The JWP was inspired by the Jerash Hinterland Survey ( JHS), which recorded many extramural water management installations close to the city during field surveys conducted 2005–2010. The

Chapter 1

2 The c. 108 km2 study area encompasses the ancient city and two valleys that formed its immediate hinterland and constitutes the core of Gerasene territory.6 The JWP was inspired by the Jerash Hinterland Survey ( JHS), which recorded many extramural water management installations close to the city during field surveys conducted in 2005, 2008, and 2010.7 In order to consider broader issues related to water management systems, it is necessary to have an understanding of the system’s components and use. To this end, the initial objectives were to identify and document the water sources and their hydrogeo­logical and palaeoclimatic contexts, to identify and document the water distribution and storage infrastructure, and to identify the public, domestic, agricultural, and industrial water demands in both urban and rural contexts. Once these objectives had been achieved, the data were synthesized and integrated into a reconstruction of the intramural and extramural water supply network in several time periods. This, in turn, provided a diachronic understanding of water availability, water use, and the water management system’s development, particularly in the urban setting. Consideration was given to understanding how the system was managed and the effects of climate change and natural disasters on the water management system, and the impact these factors had on urban and hinterland development. These objectives were achieved by critically evaluating evidence from all available sources: these not only included the records from nineteenth-century visitors and scholars and the extensive, modern published archaeo­logical corpus but also included new studies by the author based on selective field surveys and the interpretation of photo­graphs and remote sensing datasets. Water management system design is a function of the available water supply, the application of techno­logy, and human demand but is strongly influenced by local physio­logical and cultural factors that change over time and requires multidisciplinary and interdisciplinary considerations. A pervasive theme of the study, therefore, was the contextualization of the archaeo­logical evidence. The study breaks new ground in its comprehensive, holistic approach to water management analysis in the author participated in the 2018 and 2010 field seasons. 6  The two valleys are the Jarash valley, in which Gerasa lies, and the parallel Majarr–Tannur valley to the east. 7  For published JHS survey reports, see Kennedy and Baker 2009; Baker and Kennedy 2010; 2011. See also Amman, CBRL, MS Jarash Hinterland Survey 2010 Preliminary Report.

study area and the merging of historical records with current data. While constrained by inevitable gaps in the evidence that result from a landscape modified by natural and human agencies over a long period and limited archaeo­logical exposure through excavation, the pooled results present a core understanding of the water management system. The major water management components inside and outside the city are identified, collated, and integrated for the first time. The results are synthesized to establish the first interpretive plans of the urban system in various periods and provide a database that will hopefully inform ongoing studies of water installations within the city and the area’s settlement history more broadly. The geoarchaeo­logical studies identify fundamental changes in the interpretation of the Quaternary geo­logical history of the Jarash valley and provide insights into climatic and landscape changes in a research field that is rapidly gathering interest but which is currently constrained by the limited availability of absolute dating evidence.8

Volume Content The volume is a significant reorganization, revision, and expansion of the study results presented in the author’s unpublished doctoral dissertation.9 It embodies an interdisciplinary, thematic, and contextual approach, with each chapter building successively on previous chapters. The volume is divided into four parts: Part 1 outlines the sources of evidence and the methodo­logies employed in the study together with an understanding of the physio­ graphical and historical contexts; Part 2 comprehensively details the evidence of the core hydraulic elements that are integrated into Part 3 in a synthesis of urban water infrastructure and a diachronic interpretation of its operation as a functioning water management network. Part 4 includes the appendices. In Part 1, Chapter 2 introduces the objectives and explains the approach and methods used to identify and evaluate evidence from historical and modern sources. These sources include evidence and descriptions drawn from the oft-neglected maps, drawings, and writings of nineteenth-century visitors and scholars. Very little of the voluminous published corpus on Gerasa deals with water management, and what little there is has generally not been critically reviewed in the past. Relevant 8  9 

See Boyer 2018a; 2018d. Boyer 2019.

Introduction water management-related data derived from this corpus are critically analysed and synthesized with new data derived from the analysis of photo­g raphic and remote sensing datasets and focused field research conducted by the author. The JWP studies of terrestrial carbonates are explained, including the study of carbonate sediment in a Roman aqueduct that identified significant climatic and other evidence that reflect on the physical environment in the first and second centuries.10 The absolute dating of water installations outside the city has not been previously attempted and presents challenges. The radio­carbon dating of organic materials was found to be the most cost-effective approach, although not without its limitations, and these limitations are discussed along with the methodo­logy and materials. Chapters 3 and 4 provide broad environmental and historical context to the ensuing chapters in Part 2 and Part 3. Chapter 3 provides the physio­graphic context by describing the critical elements of the physical landscape. This chapter draws and expands on the author’s previous publications but also discusses new data and recent research by others, notably in regolith research. The geo­logy of the Jarash valley is revised by providing evidence that the surface bedrock geo­logy in the city area and the central part of the Jarash valley is a calcretized conglomerate formation ( Jarash Conglomerate) of likely Pleistocene date and not Upper Cretaceous Na’ur limestone as previously supposed. The various roles the Jarash Conglomerate has played in the history of the study area are summarized. The comprehensive section on hydro­log y describes the aquifers and provides the technical background to springs as an essential primary water source. The section on the seismo­logical setting informs the later discussion on earthquake impacts on buildings and the landscape, and the chapter concludes with an interpretative overview of the palaeolandscape history. The historical context in Chapter 4 traces the study area’s settlement history and the progressive increase in water demand and in the sophistication of the water management system put in place to manage that demand, placing the study period in a broader temporal context that had its beginnings at least as far back as the Neolithic period. In Part 2, the hydraulic system components are considered comprehensively and systematically in Chapters 5, 6, 7, and 8, which cover water sources, water transport, water storage, and water use, respectively. These four chapters are mainly descriptive and make up a substantial part of the volume, and the information in the text 10 

See Passchier and others 2021.

3 and related Appendix catalogues establish a resource base for future studies on the water management system. Chapter 5 integrates the available information on surface and bedrock water sources. Springs, the principal water source from the Classical period, if not earlier, are described comprehensively, and settlement locations are discussed in the context of water availability. Chapter 6 describes the means of water transportation and focuses on aqueducts and aqueduct networks. An overview of aqueduct typo­logy and conduit hydraulics is followed by a detailed analysis of the nature and distribution of various aqueduct networks and is followed by commentary on the control and management of these networks. The results of recently published research into the palaeoclimatic proxy data contained in the carbonate sediment lining one of the significant aqueducts to the city are discussed along with the results of a diachronic study based on the radio­carbon dating of charcoal in aqueduct plaster. The comprehensive description of water storage infrastructure in Chapter 7 distinguishes between the various storage installations based on their construction, location (inside and outside the city), size, and water source (aqueduct-fed versus runoff ). Chapter 8 identifies and describes all forms of water use in both urban and rural contexts. Little is known of private water use in the city, and consideration of urban water use focuses on the demand from bathhouses and fountains, but a note is also made of various industrial demands and of ecclesiastical and cultic uses. Outside the city, demand is dominated by agricultural needs, especially for irrigation, although industrial activities such as olive oil production were also carried on inside the city. Part 3 encompasses the urban water network and is divided into two parts. The evidence of the various types of installations that transport, store, distribute, or drain water in the ancient city is presented and discussed in Chapter 9. These components are synthesized in Chapter 10 in a diachronic interpretation of the water management system at various times in the city’s development. Societal changes and changes to the physical environment and their impact on water distribution and management that occurred in the Byzantine period are explained and discussed, and comparisons are made between the components in the Gerasene system and those in other cities. The study’s conclusions are presented in Chapter 11. The Appendices in Part 4 encompass details of aerial photo­g raphs consulted during the study, the JWP site database, radiocarbon dating and seismic event datasets, and catalogues of key hydraulic network components.

Part 1 Study Approach and Contextual Background

Figure 2.1. The regional physio­graphical setting of the study area. Satellite base map data, Google © 2021 Maxar Techno­logies; © 2021 CNES/Airbus.

Figure 2.2. A contoured digital surface model (DSM) of the study area. Fivemetre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

Chapter 2

Information Sources and Methodol­ ogy

The Study Area

Figure 2.3. Map of the study area showing drainage lines and key spring locations within the Jarash valley and Majarr–Tannur valley catchments.

Introduction The holistic study collected evidence from diverse sources using a variety of methods and viewed the evidence in its historical, archaeo­logical, and geoarchaeo­logical contexts. Given the lack of any previous investigation in the subject matter, this study was necessarily comprehensive, as it is only possible to consider the operation of a water management system if there is an understanding of all of the system’s components. It drew on written and photo­ graphic evidence in the published corpus, augmented by unpublished archival material, combined with the collection of new evidence from ground surveys conducted by the author. A similar approach was applied by others to the assessment of the water supply system to Hippos, although the Hippos study did not focus on the water management system. 1 Descriptions of these various sources of evidence are presented below. The application of the combined approach was not uniform within the study area, as preliminary analysis revealed a concentration of evidence of water installations on the lower slopes of the Jarash valley downstream of spring sources, and no systematic ground surveys were conducted inside the ancient walled city itself. 1 

See Tsuk 2018.

The ancient city lies in the foothills of the Ajlun Mountains 50  km north of Amman (ancient Philadelphia), the modern capital of Jordan. These mountains are bounded by the Irbid Plateau to the north, the Zarqa River to the south, and the Mafrak Plateau to the east (Fig.  2.1). 2 The boundary of the area selected for the study is the watershed that defines the combined catchments of the Jarash valley and the adjacent Majarr–Tannur valley to the east. A contoured digital surface map of the study area is presented in Figure 2.2, and a diagram of the main drainage lines is presented in Figure 2.3.3 These valleys co-join 1.5 km upstream of the confluence with the Zarqa River. The natural physical boundary of this watershed was selected as the study boundary as it is clearly defined and encompasses two richly endowed valleys close to Gerasa that formed the city’s immediate agricultural hinterland. In a regional geo­ graphical context, the study area occupies the northern part of the ‘Jerash Basin’, as defined by Kennedy, which forms the western part of the much larger ‘Zarqa River Basin’ (Fig. 2.4).4 2   Cordova 2007, 32. This area is described as the ‘Ajlun Highland’ in Admiralty, Naval Intelligence Division 1943, 407–10. 3  The term ‘Jarash valley’ is applied to the continuous drainage that extends from the town of Suf in the north-west through Jarash to the confluence with the Zarqa River to the south. This valley is labelled on government topo­graphic plans at various points along its length from north to south as ‘Wadi Suf ’, ‘Wadi ed Deir’ (or Wadi ad Dayr), and ‘Wadi Jarash’. The term ‘Majarr–Tannur valley’ is applied to the continuous drainage that extends from the small village of Al Majarr downstream to the junction of Wadi Tannur with Wadi Jarash and includes the tributary Wadi Umm Qantarah. The Majarr– Tannur valley is labelled on government topo­graphic plans at various points along its length from north to south as Wadi al Majarr and Wadi al Tannur (or Wadi er Raiyasha). 4  Kennedy 2000, fig. 13; 2004a, 203–04. For a description of

Chapter 2

8

significant monuments, streets, and archaeo­logical features in this study follow the convention established in Gerasa: City of the Decapolis by Carl Kraeling.7

Previous Studies Related to Water Management

Figure 2.4. The boundary of the study area in the context of the boundaries of the Jarash Basin and Zarqa River Basin. Adapted from . Public Domain.

The boundary of Gerasene territory in the Graeco– Byzantine period is not precisely known, but several rock inscriptions interpreted by Seigne to be possible markers (horos markers) along the south-eastern boundary of Gerasene territory lie roughly along the eastern watershed of the Majarr–Tannur valley.5 Seigne regarded these inscriptions as possibly being of second-century date, but Walmsley considered it more likely that they date to the Islamic period.6 Chrono­logy and Naming Conventions The archaeo­logical chrono­logy adopted in his study is shown in Table 2.1. Unless otherwise stated, all dates in this study are ad. Where possible, the names of the the Zarqa River Basin, see Al-Abed and Al-Sharif 2008, 1204 and fig. 1. 5   The initial discoveries were reported in Seigne 1997c, and generated considerable debate. Descriptions of additional discoveries appeared in Seigne 2019b. Sartre (1997) suggested that the inscriptions might mark property boundaries rather than the boundary of Gerasene territory. Sapin (1998, 118) suggested that the inscriptions were markers demarcating the limit of the rangeland of nomads. Caneva and others (2001, 87) suggested an alternative reading whereby the markers represent termini of the municipality of Gerasa, as distinct to the territory of Gerasa, which they considered to be more extensive to the east. For a discussion on the chora of Gerasa, see Lichtenberger and Raja 2019d. 6  Walmsley 2003a, n. 9.

The present study focuses on the archaeo­logy of past water management in the study area — i.e. the water sources and the techno­logy — as this is where the bulk of the available evidence lies. The social aspects of water management, which include the control, maintenance, and management of the water resources, are not unimportant but have left a small footprint in the local archaeo­ logical record. Broadly based historical overviews have described the progressive changes in water management in response to population and other pressures and draw attention to the changes in water management strategies that followed the move to a more sedentary lifestyle in larger settlements in the Neolithic period.8 There have also been a number of site-specific and regional studies conducted elsewhere in the Decapolis, the Hauran, and the Petra region that are seen as being relevant to the present study (see below). However, the study area was unusual in the context of the Decapolis and the southern Levant in the general availability of abundant, local water supplies of good quality in the study period. Water Management Studies in the Study Area There has been no previous publication relating to the study area’s entire water management system, although studies covering some elements of the system were published prior to the commencement of the JWP. This previous research was primarily limited to studies of bathhouses and fountains, despite the relatively wellpreserved ruins on the west side of the city and intense archaeo­logical scrutiny over an extended period.9 Aspects of the water management system were included in publications by the author during the course of the project.10 Several recent studies published by the Danish-German 7 

Kraeling 1938a. See for example Oleson 2001a; Finlayson and others 2011; Berking and others 2016; Harrower and Nathan 2018. 9   For bathhouses, see Lepaon 2008; 2012a; 2012b. For fountains, see Seigne 2008. 10  For preliminary field reports to the Department of Anti­ qui­ties, see Boyer 2017b; 2018b; 2018c; 2022. For other watermanagement related publications, see Boyer 2016b; 2016c; 2018a, 2019. 8 

Information Sources and Methodo­logy

9

Table 2.1. Archaeo­logical chrono­logical chart (approximate conventional calendar years, except where shown). Series

Period

Subdivision

Years from

Years to

Pleistocene

Palaeolithic

Lower Palaeolithic

>1.5 million bc

250,000 bc

Middle Palaeolithic

250,000 bc

45,000 bc

Upper Palaeolithic

45,000 bc

20,000 bc

Epipalaeolithic

Epipalaeolithic

18,000 bc

8000 bc

Neolithic

Pre-Pottery Neolithic A

Cal. 10,000 bc

Cal. 9000 bc

Pre-Pottery Neolithic B

Cal. 9000 bc

Cal. 7900 bc

Pre-Pottery Neolithic C

Cal. 7900 bc

Cal. 6300 bc

Pottery Neolithic

Cal. 6300 bc

Cal. 4800 bc

Chalcolithic

Cal. 4500 bc

Cal. 3700/3600 bc Rowan 2014, 223.

Cal. 3700 bc

Holocene

Chalcolithic

Al-Nahar 2013a. Simmons 2007, 46.

Rollefson 2008, 71, table 4.1.

Early Bronze Age

Early Bronze Age (EB)

Cal. 1950 bc

Regev and others 2012, 555–56.

Middle Bronze Age

Middle Bronze Age (MB) 2000/1900 bc

1500 bc

Bourke 2014.

Late Bronze Age

Late Bronze Age (LB)

1550/1539 bc

1150 bc

Fischer 2014.

Iron Age

Iron Age I (IA I)

1200 bc

980 bc

Levy and others 2014, table 1.1.

Iron Age II (IA II)

1000 bc

586 bc

Hardin 2014.

Hellenistic

Hellenistic

332 bc

64 bc

Nabataean

Nabataean

300 bc

ad 106

Roman

Early Roman

64 bc

ad 135

Late Roman

ad 135

ad 324

Byzantine

Early Byzantine

ad 324

ad 491

Late Byzantine

ad 491

ad 640

Umayyad

ad 639

ad 750

Abbasid

ad 750

ad 970

Fatimid/Seljuq

ad 970

ad 1174

Ayyubid

ad 1174

ad 1263

Crusader

Crusader

ad 1100

ad 1188

Late Islamic

Mamluk

ad 1263

ad 1517

Ottoman

ad 1517

ad 1918

Modern

ad 1918

Present

Early Islamic Middle Islamic

Modern

Jerash Northwest Quarter Project (hereafter the JNWQ project) focus on water management in the city’s NorthWest Quarter and on the identification of canals based on AP analysis.11 Urban water infrastructure has been briefly discussed, but there is no published study of the city’s water infrastructure comparable to the studies on the water systems that supplied the Decapolis city of Gadara 11   For

Reference

JNWQ project studies relating to the North-West Quarter, see Lichtenberger and Raja 2012; 2017; Lichtenberger and others 2015. For publications relating to AP analysis, see Stott and others 2018, 4–7; Lichtenberger, Raja, and Stott 2019; Kristiansen and Stott 2020, 168–70. For a more general discussion on water sources and management, see Lichtenberger and Raja 2016a.

Kennedy 2004b.

Walmsley 2008

This study

in northern Jordan (see below).12 The investigations into water management in two residential areas in the western part of the city by the Late Antique Jarash project (hereafter the LAJ project) and the JNWQ project will likely expand the findings in this study when published.13 12  For commentary relating to the study area, see Stott and others 2018; Lichtenberger and Raja 2019c. For hydraulic studies on Gadara see Kerner, Krebs, and Michaelis 1997; Al-Daire 2004; Döring 2005. For regional hydraulic studies in northern Jordan see Döring 2004; 2005; 2008; 2016; Kerner 2004; Tsuk 2018. 13  For the LAJ project, see Blanke and Walmsley 2012, 703–04. For the Jerash Northwest Quarter Project, see Lichtenberger and Raja 2012–2019.

Chapter 2

10 Table 2.2. Water management-related studies in the Decapolis. Site

Study Theme

References

Abila

Hydro­logical System Techno­logy

Mare 1995.

Gadara

Water Management Overview

Kerner, Krebs, and Michaelis 1997; Kerner 2004; Döring 2005.

Urban Water Distribution and Management

Al-Daire 2004; Keilholz 2016; 2017.

Supply Aqueduct from Syria

Döring 2004; 2008; 2016.

Nymphaeum

Zens 2006.

Water Supply Overview

Tsuk 2018.

Supply Aqueduct

Ben David 2002.

Hippos

Bathhouses

Kowalewska and Eisenberg 2017; Kowalewska 2019.

Kanatha

Water Supply, Watermills

Ertel 2013.

Pella

Roman Water Installations

Watson 2001.

Philadelphia

Nymphaeum

Khalili 2013; 2014; 2016.

Umayyad Citadel

Arce 2004; 2015.

Public Baths

Mazor 1999.

Water Supply

Fahlbusch 2002.

Scythopolis

The significant monuments on the west side of the city were the main foci of archaeo­logical investigations in the study area by national and international agencies until recently. Published works on water infrastructure in the city’s hinterland include brief commentaries on the ancient rural systems east of Jarash by Jean Sapin and in the Jarash valley by David Kennedy and preliminary observations on Gerasa’s water supply in the context of its hinterland by Jacques Seigne. 14 The largely unpublished JHS results are significant as they include records of many water installations in the city’s immediate hinterland, an area that has seen much damage and destruction to the archaeo­logical heritage from building and agricultural activity in recent decades. The lack of previous research into the ancient water management system left many issues unresolved. The published archaeo­logical corpus records many water infrastructure components within the western part of the ancient city, but there was no attempt to contextualize these components within the overall storage and delivery system before the present study. The thesis by Jordan Pickett described and analysed elements of Gerasa’s intramural water management system — notably several fountains along the main street (Cardo), but was not a comprehensive synthesis. 15 Seigne studied fountains on the west side of the city; however, three of the city’s largest water installations — the Nymphaeum, 14  15 

Sapin 1998, 112; Kennedy 2007, 68–70; Seigne 2008. Pickett 2015.

the West Baths, and the Large East Baths — have yet to be fully excavated and studied.16 The partially excavated Nymphaeum has been dated from a dedicatory inscription to ad 190/91, but its period of use is uncertain.17 The precise dates of construction and use of the West Baths and the Large East Baths have still to be determined.18 There was no published analysis of water sources before the commencement of the JWP. The supply of water to the east side of the city in Antiquity above the elevation of the Qairawan spring was also unknown prior to the JWP. Qairawan spring has long been recognized as an essential intramural source on the east bank of the wadi and remains so to this day; however, its use prior to the Roman period is obscure. The spring lies below the level of the fountains and baths on the west side of the city, and this reality sustained the widely held assumption that water from the spring and the reservoir complex at Birketein, 1.6 km north of the city, supplied the west side of the city, even though little evidence was put 16  Seigne 2008. For details on the West Baths and Large East Baths, see Lepaon 2008; 2012a; 2012b. 17  For the Nymphaeum inscription, see Welles 1938, 406, no. 69. Analysis of the available evidence has identified inconsistencies in the interpretation of the inscribed blocks presented by Welles that leads to the conclusion that the inscribed blocks formed part of more than one inscription. The issue is discussed further in the description of the Nymphaeum (fountain 6) in Appendix I. 18  For detailed descriptions of the bathhouses within Gerasa, see Lepaon 2012b.

Information Sources and Methodo­logy forward to support the contention.19 In contrast, Jacques Seigne posited that the city’s water source probably lay upstream of Birketein.20 Several publications referred to ancient aqueducts in the city’s hinterland; most relate to the Jarash valley, and there were references to several ‘micro-irrigation systems’ in the Majarr–Tannur valley.21 Water Management Studies in the Southern Levant The research approach into Levantine water management systems has to date primarily focused on overviews of one or more components of the system, and usually in the context of more comprehensive studies of a particular site. Such studies also tend to be short-term in their coverage, with a focus on the Roman and Byzantine periods.22 Aqueducts and water supply have been a particular focus across the Levant, and the studies of aqueducts supplying Ephesus and Antioch in the northern Levant and the Decapolis aqueduct supplying Gadara and neighbouring cities in the southern Levant stand out in their comprehensive coverage.23 The Humayma Hydraulic Survey of the area surrounding the Hawara Nabatean settlement is a rare example of a comprehensive, multiperiod, holistic study that encompasses all aspects of a water management system.24 Published water management-related studies in the Decapolis are summarized in Table 2.2. The beststudied area in the Decapolis is Gadara, together with its extended supply aqueduct network from sources in southern Syria that also supplied the cities of Adra’a and Abila. The water supply system to Hippos has also been reasonably well studied. The water management system of Philadelphia (modern Amman) in the Classical period is poorly understood, but research has provided valuable insights into the Citadel’s water management system in the Umayyad period. An important regional, long-term water management overview of the Hauran region in Syria that adjoined the Decapolis includes 19  For commentary on Birketein as the water source for the city, see Fisher 1932, 11; McCown 1938a, 162; Browning 1982, 213; Watts 1984, 23; Freeman 2008, 21. 20  Seigne 2004, 176. 21  For references to aqueducts, see Seigne 2004; Baker and Kennedy 2011. For ‘micro-irrigation systems’, see Sapin 1998, 112. 22  Although lying on the periphery of the southern Levant, studies from Yemen provide a useful long-term view of water management; see for example Harrower and Nathan 2018. 23  For Ephesus, see Wiplinger 2019. For Antioch, see Döring 2020. For the Decapolis aqueduct, see Döring 2004; 2008; 2016. 24  Oleson 2010.

11 commentary on the water supply to Bosra, the provincial capital of Arabia Petraea.25 There have been numerous aqueduct studies on sites west of the Jordan valley. Details of twenty-eight systems were published in The Aqueducts of Israel: the urban systems include Graeco-Roman and Hasmonean/ Herodian types, while the so-called desert systems are Hasmonean/Herodian. 26 Of the urban systems, the aqueducts supplying Caesarea Maritima and Jerusalem have been particularly well studied.27 Many more systems were described in the Cura aquarum in Israel volume.28 Significant regional water management studies have been conducted on areas west of the Jordan valley, notably by John Oleson, while Nabataean water management has been studied comprehensively at Petra and nearby Humayma.29

Past Field Surveys A core element of the present study was the recording of archaeo­logical sites related to the ancient water management system in the city’s hinterland using focused fieldwalking surveys. The JHS used a similar approach and recorded a total of 1141 archaeo­logical sites within a 3.8 km2 area immediately surrounding the ancient city.30 Ten per cent of the JHS sites were water-related; however, the present study was the first to focus on waterrelated installations. Many archaeo­logical ground surveys have been conducted in north-west Jordan to date, and some of these partially cover the study area (Fig. 2.5 and Table 2.3). The study divided the previous ground surveys into two groups based on the intensity of coverage and recording detail. 31 The first (regional non-selective) group 25 

Braemer and others 2009. 26  Amit, Patrich, and Hirschfeld 2002. A useful overview of water management in this volume is provided in Patrich and Amit 2002. 27   For Caesarea maritima, see Peleg 2002b; Porath 2002; Siegelmann 2002. For Jerusalem, see especially Amit 2002; Billig 2002; Mazar 2002, but see also Wilkinson 1974; Gurevich 2020. 28  Ohlig, Peleg, and Tsuk 2002. 29  For regional studies, see Oleson 2001a; 2001b; 2018; Shqiarat 2008. For studies of Petra, see Ortloff 2005; Lavento and others 2004; Bellwald 2008; Plekhov 2021. For Humayma, see Oleson 2010. 30  See Kennedy and Baker 2009; Amman, MS Jarash Hinterland Survey 2010 Preliminary Report; Baker and Kennedy 2010; 2011. 31  This grouping differs in some respects from the grouping of ground surveys in north-west Jordan adopted by Kennedy (2004a, table 1).

12

Chapter 2

Figure 2.5. The boundaries of geo­graphically selective regional surveys and more detailed surveys impacting the study area.

Figure 2.6. A map of a 5 km2 area west of the modern village of Umm Qantarah Al Gharbiyya in the Majarr valley showing the modern expansion of rain-fed olive orchards and farm estates onto south- and west-facing slopes with thin soils in the context of ancient field walls. Satellite base map data, Google, Landsat Copernicus © 2021 CNES/ Airbus.

Information Sources and Methodo­logy

13

Table 2.3. Table of ground surveys conducted wholly or partially within the study area. Survey Name

Type

Reference

Schumacher

Regional non-selective

Steuernagel 1924; 1925; 1926.

Eastern Palestine

Regional non-selective

Glueck 1934a; 1934b; 1935; 1939a; 1939b; 1942; 1951.

Mittmann

Regional non-selective

Mittman 1970.

Jarash-Tell El Husn Highway

Local, geo­graphically selective

Leonard 1987.

Wadi as-Zarqa

Local, chrono­logically selective

Sala 2008.

Kirkbride

Local, chrono­logically selective

Kirkbride 1958.

Jarash Region Survey

Local, chrono­logically selective

Hanbury-Tenison 1987.

East Jarash

Geoarchaeo­logical, locally intensive

Sapin 1998.

Jarash Hinterland Survey

Local, intensive

Kennedy and Baker 2009; Baker and Kennedy 2010; 2011.

focused on the preliminary recording and dating of individual rural occupation sites of all ages identified from wide-ranging, regional-scale surveys through the study of sherd scatters. The Jarash-Tell El Husn Highway Survey is an example of a more localized regional survey within this group. The majority of sites recorded appear to have been small settlements: the largest were generally small villages, and the smallest perhaps hamlets or even individual farms. The second (local, chrono­logically selective) group recorded similar information as the first group but focused on sites relating to specific occupation periods within a smaller geo­graphic area. The two locally intensive surveys produced quite different results. Sapin’s study of the Ajlun–Jarash district pioneered the geoarchaeo­logical approach in the district,32 and he used a similar approach in a later study of an area east of Jarash that included the Majarr– Tannur valley.33 While still focused on settlement sites, his valuable study east of Jarash compared ‘l’intégration spatiale des populations agro-pastorales sédentaires et semi-nomades’ in two adjoining areas: the Majarr– Tannur valley (Sector XI) and the Wadi Sahban basin to the east (Sector XII) that lies outside the present study area. Sapin viewed human use of these areas in the context of the physical environment (climate, geomorpho­ logy, soils, and water availability). He saw agriculture being focused on areas with deeper soil, with areas of what he considered to be strongly eroded soils on steeper 32 

Sapin 1985. Sapin 1998. Sapin divides his study area into nineteen sectors (1985, fig. 2): Sector VII is almost identical with the boundary of the Jarash valley used in this study and Sector XI broadly coincides with the Majarr–Tannur valley. Sapin’s survey results (and others) were included in a comprehensive critical review and analysis by Bradbury, Braemer, and Sala 2014. 33 

slopes and upland areas being used for pastoral pursuits. He classified ‘agricultural structures’ as villages, farms, or villas, while religious sites (convents, sanctuaries) and military posts were also recognized. A revealing intensive study of a 4 km × 4 km area around Umm Qantarah identified networks of field and terrace walls that were attributed to the first-century bc and first-century ad period.34 Much of the evidence has since disappeared, but it is interesting to note the recent introduction of rain-fed olive orchards and farm estates into the same field areas on the south- and west-facing slopes, even where soils are thin. An example of a 5 km2 area west of the modern village of Umm Qantarah Al Gharbiyya is shown in Figure 2.6. In contrast to all the other surveys, which focused on settlement sites, the JHS study surveyed a broad range of archaeo­logical sites in the city’s immediate hinterland encompassing all occupation periods. It provides baseline data for an area that has experienced a significant loss of archaeo­logical sites to modern development and is a valuable addition to the archaeo­logical corpus in the near-city area.

Primary Literary and Non-Literary Sources The study identified four types of primary sources (viz. literary, epi­graphic, mosaic, and numismatic), but these sources yielded little evidence relevant to water management. Few primary literary sources from the Classical period mention or refer to Gerasa, and none of the primary texts mentions the city’s water management system or 34  Sapin 1998, 129. For an alternative explanation that the ancient field walls were on built slopes already depleted of soil, see Lucke 2017, 136.

Chapter 2

14 its components.35 Several primary texts from the first to sixth centuries record Gerasa’s inclusion in the Decapolis but provide no details about the city or its territory.36 Jarash is mentioned by the Arab geo­g rapher Al-Ya’kûbi (d.  897/98) in c.  ad  891 and by Yâkût (d.  1229) in ad 1225. Both were writing after the study period, but their observations provide rare contemporary insights into conditions in the city. Al-Ya’kûbi noted that the population in the town was half Greek and half Arab,37 yet less than 250 years later, Yâkût reported

consumers.43 Much of the numismatic material recorded since the commencement of the Jarash Archaeo­logical Project has yet to be published.44 There are no examples of Gerasa’s water infrastructure or water monuments represented in published numismatic material, but river gods are commonly depicted on coins from the second half of the second century and the early third century.45

Jarash is the name of what was once a mighty city but is now a total ruin. This I am told by those who have seen it. There are wells of the ‘Adite days to be seen here. Through its midst runs a river, which turns at the present day several mills.38

Published secondary literary sources were examined for evidence relating to water management. There is an extensive and rapidly expanding published corpus relating to archaeo­logical investigations conducted in the twentieth century, but the review also encompassed literary sources relating to visits to the area by foreigners in the nineteenth century. In the course of the review of the published corpus, relevant archives were visited in the USA (Yale University), UK (Dorchester, London, and Oxford), and Germany (DAI, Berlin).

Mosaics have been recorded from various buildings in Gerasa.39 Water-related scenes include the representations of waterbirds and fish in mosaics from the Church of St Cosmas and Damian, the Church of the Apostles Prophets and Martyrs, and the Church of Saints Peter and Paul.40 Perhaps the most significant depiction is a riverine landscape with ducks and fish in the mosaic from the Church of St  John the Baptist.41 Such landscapes elsewhere in the Levant are generally taken to be Nilotic scenes, but in Gerasa, the scene also resonates, perhaps, in the context of Wadi Jarash and the city’s Hellenistic toponym, Antioch on the Chrysorrhoas.42 More information on the city’s water management system was revealed in a review of the published corpus of inscriptions, which identified six Greek inscriptions relating to water installations or water 35  For a summary of references, see Kraeling 1938a, 28–63; Cohen 2006, 248–53. 36   They include the philosopher Pliny the Elder and the historian Josephus in the first century, the geo­grapher and scientist Ptolemy in the second century, the historians Eusebius of Caesarea and Ammianus Marcellinus in the fourth century, and the Greek grammarian Stephanus of Byzantium in the sixth century (Cohen 2006, 248–53). 37  Al-Ya’kûbi, cited in Le Strange 1890, 462. 38  Yakut, cited in Le Strange 1890, 462. 39   See Crowfoot 1931a, 39–48; Biebel 1938, 297–352; Piccirillo 1993, 272–300. 40  Biebel 1938, 327–37. 41  Biebel 1938, 327. 42  Hachlili (1998, table 1) provided a list of ‘Nilotic elements on Byzantine Mosaic Pavements’ in Israel, Jordan, Syria, and North Africa. Nilotic scenes had long been a feature of Roman decoration: see for example Meyboom 1995, 350–52.

Secondary Literary Sources

Nineteenth-Century Sources The study found evidence of recorded water-related features in nineteen visits to Jarash by outside parties before the Circassian settlement in 1878 in published and unpublished accounts. The details are presented in Table A1 in Appendix A. The establishment of the Circassian colony c. 1878 resulted in significant damage to the extant ruins, and details of the city area recorded by visitors before this date are, therefore, precious, and in some cases are unique.46 The importance of these con43  Welles (1938, 355–494) remains a key epi­g raphic reference, with more recent information provided by Agusta-Boularot and Seigne (2002; 2005), Agusta-Boularot, Seigne, and Mujjali (2004), and especially by Gatier (1982; 1988; 2002). The inscriptions relating to water installations or water consumers comprise a firstcentury dedication to a reservoir or pool in the Artemis complex (Welles 1938, 389, no.  28), two second-century dedications to fountains (Welles 1938, 404, no. 63; 406, no. 69), two early thirdcentury dedications from an association of fullers (Gatier 1985, 308), an association of gardeners (Gatier 1985, 310–12), and two sixth-century dedications to a ‘pool, bath or canal’ (Welles 1938, 469–70, nos 277–78). 44  See Bellinger 1938; Spijkerman 1975; Walmsley 1999; Birch and others 2019. 45  See Spijkerman 1975, 77–82. 46   For an over view of nineteenth-century visitors, see Mortensen 2018. For specific commentary on the contributions by William Bankes and Charles Barry, see Boyer 2015; 2016a.

Information Sources and Methodo­logy Table 2.4. List of town plans of Gerasa drawn by nineteenth-century visitors. Author

Visit Date

First Publication Date

Burckhardt

1812

1822

Burckhardt*1

1812

1824

Bankes

1816

Unpublished

Buckingham

1816

1821

Barry

1819

Unpublished

1820

Unpublished

Barry

*2

1820

2019

Rey

1858

1859

Warren

1867

1870

Kiepert

1868

1870

1891–1902

1902

Vidua

*3

Schumacher

Hybrid plan in German edition (Burckhardt 1824) combines Burckhardt’s plan with Buckingham’s 1821 plan. *1

*2

Compilation from Bankes and Barry visits 1818–1819.

*3

Variant of Burckhardt’s 1812 plan.

tributions is variable due to the knowledge, skill sets, and experience of the party, the size of the surveying party, and the length of time the party spent on the site, but even observations by tourists can provide corroborative evidence. Many visits to Jarash were of short duration, typically one or two days, notable early exceptions being those by the classicist and explorer William Bankes. 47 The records of the nineteenth-century visitors typically included written descriptions that were occasionally augmented with plans and other visual presentations and, from 1844, photo­graphs. Ground plans of the city area are valuable sources of archaeo­logical evidence, and a list of published and unpublished plans by nineteenthcentury visitors is given in Table 2.4.48 For commentary on contributions by James Buckingham, see Boyer 2017a. A comprehensive assessment of the contributions by nineteenth-century visitors will be provided by Lichtenberger and Raja (eds) (forthcoming). 47  Details of the duration of important visits between 1805 and 1819 are given in Boyer 2015, 37–38, fig. 4.1. 48  These plans are discussed further in Boyer 2016a, 288–96. Koch (2013, 42) posited that Catherwood ‘managed to find the time to make the first detailed map of Gerasa’ during his visit in 1834 and that this map ‘became part of the Robert Hay collection that was bestowed to the British Museum’. Koch is incorrect; the map attributed to Catherwood, now in the British Library (London, BL, ADD.M.29859_f. 44), is a hand-drawn coloured copy of the plan of the city published by Buckingham (1821, 342).

15 Detailed plans of monuments and buildings were recorded by Bankes, Buckingham, Barry, Warren, and Schumacher.49 Before the introduction of photo­graphy, the appearance of the site was preserved in landscape drawings, watercolours, and litho­g raphs; foremost among these are the drawings and plans by Bankes and Barry in the DHC and RIBA archives, and the drawings by William Tipping in 1842 in the Victoria and Albert Museum archive. Well-executed litho­graphs of views of the western side of the city were published by Léon de Laborde, who visited the site briefly in 1827.50 The first known photo­g raphs were taken in 1844, and by the 1870s, views of Jarash were regularly being taken by the leading contemporary Levantine photo­graphers.51 Taking into account site descriptions, plans, and drawings, the most significant archaeo­logical contributions from nineteenth-century visitors come from three sources: (i) the records of private visits made before 1820; (ii) the Palestine Exploration Fund (PEF)-sponsored expedition by Warren in 1867; and (iii) the PEF-sponsored expeditions by Schumacher between 1891 and 1900. The first known European visitor to Jarash was the German geo­g raphic explorer Ulrich Seetzen, who was sponsored by the fledgeling Palestine Association. His one-day visit in March 1806 provided a brief description of the ruins and the first confirmation that the site was Gerasa but did not refer to water-related infrastructure.52 He was followed six years later by the Swiss explorer and orientalist Johann Burckhardt, who spent only a few hours on the site but completed a circuit around the city walls and provided the first published ground plan of the city.53 Burckhardt was also the first to note details of springs in the Jarash valley and aqueducts in the city. The period 1816–1819 saw six visits by English parties, three of which were led by William Bankes. Very little of Bankes’s commentary on these visits has survived, 49  For descriptions of the plans and drawings of Bankes and Barry, see Boyer 2015; 2016a. Buckingham’s plans and drawings published in 1821 are virtually identical to plans and drawings by Bankes that relate to the visit on 31 January–1 February 1816 (Boyer 2017a), although Buckingham later claimed that they were drawn during a later separate visit by him (Boyer 2017a, 188–89). For the plans and drawings by Charles Warren, see London, PEF, Charles Warren Archive. For Schumacher, see Schumacher 1902. 50  de Laborde 1837, 94–98. 51  The photo­g raphs taken in 1844 were published as litho­ graphs in Keith 1848. 52   Seetzen 1810, 32–34. For commentary on the Palestine Associ­ation, see Kark and Goren 2011, 264. 53  Burckhardt 1822, 251–65.

Chapter 2

16

Figure 2.7. Plan de Djérasch (Gérasa) by Gottlieb Schumacher. From Meistermann 1909, 321. Public Domain.

and we must rely on published descriptions by several of his travelling companions — especially Buckingham, Finati, Irby, and Mangles, and on the plans and drawings in the DHC and RIBA archives.54 Barry was responsible for compiling the results of Bankes’s 1816 and 1818 visits onto detailed and accurate plans and architectural 54  For Bankes’s commentary, see Bowsher 1997. For descriptions by Bankes’s travelling companions, see Buckingham 1821, 349–405; Irby and Mangles 1823, 308–18; Finati 1830, 148–51.

drawings for inclusion in a publication project that was never completed.55 A detailed plan of the city titled ‘General Plan of the Rvins [sic] of Djerash’ (hereafter the General Plan) compiled by Barry in 1820 shows a level of detail and accuracy that was not surpassed in the nineteenth century. 56 In addition to recording several water installations within and adjacent to the city, the General Plan includes the first known representation of the B i r ke t e i n r e s er v o i r north of the city. Close study has found Bankes’s water­c olours to be factually accurate, and they provide valuable contemporary evidence of site conditions a quarter of a century before the first photo­g raphs of Gerasa by George Keith published as engravings by his father, Alexander Keith, in 1844.57 The significance of Charles Warren’s fourday sur vey of Gerasa conducted in August 1867 lies in his photo­graphs and drawings of individual monuments, now in the PEF archives, rather than in the brief published description and his survey sketch of the city.58 Warren felt that he could add little to the descriptions of the site published by Burckhardt and Buckingham; however, this may have been an after55  Boyer 2015. Contrary to March (2009, 260), Barry did not travel with Bankes but led a separate party to the site in May 1819. 56   Dorchester, DHC, D-BKL/H/J/7/3/1. The plan was published in Boyer 2015, 44, fig. 4.3. 57  Keith 1848. 58  See Warren 1870.

Information Sources and Methodo­logy thought, as he admits that he failed to take copies of these publications with him on his field visit.59 Warren’s drawings of the Artemis Temple include the first detailed plan of the massive vaults beneath the cella, and his detailed plan of the Large East Baths contains unique detail. Gottlieb Schumacher made many visits to Jarash between 1891 and 1900, and his descriptions of the site and immediate hinterland were consolidated in his 1902 publication Dscherasch.60 His city plan lacked some of the detail contained in Barry’s General Plan but was the first to contain elevations and detailed topo­graphic cross-sections of the city based on a theodolite survey (Fig. 2.7).61 Schumacher was also unique among nineteenth-century visitors in that he published detailed plans and drawings of the Birketein reservoir and the adjacent theatre. Post-Nineteenth-Century Sources The corpus of archaeo­logical literature on various sites within and adjacent to Gerasa is substantial. Archaeo­ logical activities at Gerasa in the quarter of a century following the publication of Schumacher’s Dscherasch were limited mainly to epi­graphic studies, especially by Lucas and Thomsen.62 A party led by Otto Puchstein spent a month on the site in 1902, but the publication of the findings was limited to brief commentary and several photo­graphs and drawings.63 The first systematic field-based archaeo­logical activities in Gerasa were initiated and supervised in 1925 by George Horsfield, an architect employed by the newly formed Department of Antiquities of Palestine. The work in this early phase focused on urgent repairs and the need to conserve major monuments to make the site accessible and appealing to tourists.64

See Warren 1870, 301. Schumacher 1902. For Schumacher’s extensive travels in Jarash’s broader hinterland, see Steuernagel 1924; 1925; 1926. 61  Schumacher 1902, pls 6–7. 62  See Lucas 1901; Thomsen 1917. For commentary on late nineteenth–early twentieth-century excavations and exploration, see Stinespring 1938. 63  Puchstein’s visit was referred to by Stinespring (1938, 2). For the photo­graphs and drawings, see Krencker 1934, 25–27, figs 4–14. The sites in Jarash visited by Puchstein’s party are listed in Puchstein and others 1902, 106. See also the discussion in Lichtenberger and Raja 2020, 13–14. 64  See Horsfield 1926.

17 Further systematic archaeo­logical excavations were carried out by a joint team from Yale University and the British School in Jerusalem under the field direction of John Crowfoot, and later by a joint Yale-American Schools of Oriental Research (ASOR) team under the direction of Clarence Fisher in a series of field campaigns conducted between 1928 and 1934 (hereafter collectively referred to as the Yale Mission).65 The work was confined mainly to urban sites. The team initially focused on excavating the Christian churches under Crowfoot; however, the focus shifted to the pre-Christian monuments under Clarence Fisher. The results were published in a series of annual reports by John Crowfoot, Clarence Fisher, and Chester McCown and ultimately compiled into a mono­g raph, Gerasa: City of the Decapolis, edited by Carl Kraeling, which remains an essential archaeo­ logical reference.66 Separate studies were published on the churches, inscriptions, and coins; however, much of the work conducted between 1928 and 1934 is unpublished, and the records are retained in the Yale University Art Gallery (YUAG) Gerasa Collection.67 Clearance and conservation work continued in the late 1930s and resumed in the post-WW2 period under the direction of Lankester Harding.68 Archaeo­logical activities in the 1950s, 1960s, and early 1970s were mainly limited to restoration work on several monuments; for example, the work by Diana Kirkbride on the South Theatre and clearance and restoration work by the Department of Antiquities of Jordan (DOA) supervised by Haroutune Kalayan.69 Plans for the creation of the Jarash National Park in the 1960s stimulated renewed interest in the site, and a ‘Master Plan’ was prepared for the Jordanian government.70 The late 1970s saw a move towards a better understanding of the occupational and strati­graphic historio­graphy of the city with the instigation of excavations in the city’s South-West Quarter in 1975–1977 by Asem Barghouti.71 This work identified new buildings of Hellenistic date and a revised under-

59 

60  

65  In 2020 ASOR changed its name to the American Society of Overseas Research. 66  Kraeling 1938a. For the annual reports, see Crowfoot 1929b; Fisher 1930; 1931; 1932; 1934; McGown 1931. 67   For the Christian churches, see Crowfoot 1929a; 1930; 1931a; 1931b. For the inscriptions, see Jones 1928a; 1928b; 1930. For the coins, see Bellinger 1938. 68  Harding 1949. 69  Kirkbride 1960; Kalayan 1981, 1982. 70  Jordan, Jordan Planning Team 1968. 71  Barghouti 1982.

Chapter 2

18 standing of street layout in the South-West Quarter. Archaeo­logical momentum was sustained with an evaluation of the Artemis Sanctuary by an Italian team under Roberto Parapetti in 1977.72 The Jarash Archaeo­log y Project ( JAP) initiative launched by the Jordanian government in 1982 was the most significant advancement of archaeo­logical activity since the Yale Mission. The focus was on the excavation and preservation of the pre-Islamic buildings and monuments and the western side of the city, which was partitioned into excavation areas divided between various international archaeo­logical teams. These excavation areas had ceased to have much meaning by the end of the 1990s, and research horizons expanded. Outcomes of this approach included the ‘Jerash City Walls Project’, and the discovery of the remains of a sixth-century watermill-powered stone saw in the Artemis Sanctuary.73 The DOA continued to carry out excavation and restoration activities throughout this period; however, very little of this work has been published. By the end of the 1990s, the main JAP excavation activities had been completed, and attention turned to restoration. The practice has been for the international teams to publish only interim and occasional reports on their projects, with the result that no comprehensive reports synthesizing the activities and the results have yet been published for the larger projects such as the Zeus and the Artemis Sanctuaries and the ‘Islamic Jerash Project’. By the end of the 1990s, archaeo­logical knowledge of Gerasa had materially advanced, but the results were strongly prejudiced in favour of the archaeo­ logy of the Classical period, especially the significant monuments. Less than 15 per cent of the city area had been excavated, and nearly all of this was on the west side. Minimal work had been directed towards the suburban living areas before the excavations in the SouthWest Quarter by Barghouti, and the eastern side of the city was terra incognita in terms of its archaeo­logical historio­g raphy.74 These prejudices were reflected in the review of the city’s urban setting expressed in Gerasa: City of the Decapolis and continued to constrain the better-informed interpretations of the city’s urban plan and historio­graphy published in the 1980s and 1990s.75 72 

See Parapetti 1983–1984; 1989; 2012. For a summary of the results of the Jerash City Walls project, see Kehrberg-Ostraz and Manley 2019. For the stone saw, see Seigne 2002a; Seigne and Morin 2007; 2008. 74  Barghouti 1982. 75   See Fisher 1938a, 14–15. For the city’s urban plan and 73 

Two significant subsequent developments record welcome changes to the archaeo­logical focus within the city. The first, the work by the Islamic Jarash Project team on the Umayyad Congregational Mosque initiated in 2002 under the direction of Alan Walmsley, was the first major project within the city to focus on the archaeo­logy of the Islamic period. The mosque was constructed over an earlier bathhouse, the Central Baths, and investigations have conclusively demonstrated that the city continued as an urban centre into at least the tenth century. 76 The second was the JNWQ project initiated in 2011, directed by Rubina Raja and Achim Lichtenberger. This comprehensive project focuses on the domestic settlement history of a part of the city away from the major monuments and has already yielded valuable information on the area’s settlement history and the water supply network.77

Visual Sources The changing landscape in the project area brought about by natural weathering processes and the passage of time was exacerbated with the resumption of permanent occupation of the city area by Circassian colonists in 1878, and significantly accelerated in the late twentieth century with the growth of the modern town and administrative centre of Jarash. Investigations demonstrated that these changes could be traced in the records, plans, and drawings of the early nineteenth-century visitors, but the development of photo­graphy — and in particular the use of aerial photo­graphy during WW1 — introduced a valuable new information-recording medium for researchers. The development of remote sensing in the form of satellite imagery has added new perspectives, mainly when applied in a Global Information System (GIS) context, with the airborne laser scanning (ALS) survey results published by the JNWQ project being the most recent manifestation.78 All of these information historio­g raphy, see Barghouti 1982; Parapetti 1983–1984; Seigne 1999a; 1999b. 76   See Walmsley and Damgaard 2005; Blanke and others 2007; Blanke 2015. The LAJ project is investigating the domestic settlement history in the South-West Quarter of the city (Blanke and Walmsley 2012). 77  For the settlement history, see Lichtenberger and Raja 2015; 2016b; 2018a; 2018b; 2019a, 2019b. For the water supply network, see Lichtenberger and Raja 2017; 2019c. 78  See Stott and others 2018; Lichtenberger, Raja, and Stott 2019.

Information Sources and Methodo­logy

19

Figure 2.8. Engraved photo­ graph of the western side of Gerasa, one of three views taken by George Keith in 1844. Reprinted from Keith 1854. Public Domain.

Figure 2.9. Litho­graphed photo­graph of the western side of Gerasa taken in 1858. Reprinted from Rey 1861, fig. XX. Public Domain.

sources were utilized in the evaluation of the evidence relating to the water management system in the present study. Ground Photo­graphy The study made extensive use of historical (pre-1977) ground photo­g raphs. There had been a selective use of such photo­g raphs by several researchers in the Gerasa area previously, and the present study found that these photo­g raphs to be a valuable record of archaeo­logical evidence in the city area.79 79 

For an example of the previous use of early photo­graphs, see Seigne 1989a.

The first ground photo­g raphs of Gerasa were three daguerreotype views taken by George Keith in 1844 and published by his father, the Reverend Alexander Keith, as litho­g raphs (Fig. 2.8).80 They provide an early visual snapshot of the ruins on the west side of the city and can be used to corroborate the statements made by early nineteenth-century travellers. Fourteen years later, the young French surveyor Emmanuel Guillaume-Rey took several daguerreotype photo­g raphs of monuments on the west bank of the city, including a detailed panorama that is presented in Figure 2.9.81 80  81 

See Keith 1848; Howe 1997, 23. Rey 1861, pl. XX.

Chapter 2

20 Litho­g raphs of original photo­g raphs were used in publications in this early period, as the reproduction of daguerreotype photo­graphs proved difficult. GuillaumeRey’s photo­graphs, together with a series of eight photo­ graphs taken in 1864 by Louis Vignes and photo­graphs taken later by Henry Phillips and Tancrède Dumas, form a valuable historical photo­g raphic corpus of the city in the fifteen years preceding Circassian settlement.82 While these photo­g raphs mostly depict views of the western side of the city, background views also provide visual records of the eastern part of the city before the establishment of the Circassian village in 1878.83 The photo­g raphic corpus rapidly expanded in the late nineteenth century–pre-WW2 British Mandate period, with material from visitors and professional photo­graphers such as Bonfils, Dumas, and others from the American Colony in Jerusalem.84 Abamelek-Lazarev, Schumacher, and Libbey and Hoskins were notable contributors to the photo­g raphic corpus around the turn of the twentieth century.85 The number of photo­graphs increased exponentially during the first half of the twentieth century with the addition of the photo­graphs taken during the clearances and archaeo­logical excavations conducted by the Yale Mission. The dearth of archaeo­ logical activity in the post-WW2 period before 1977 is reflected in the reduction in published photo­g raphs from this period. While some ground photo­graphs were published,86 most were not and were retained in scattered archives around the world. Many photo­g raphic archives were accessed during the present study, including repositories in the United Kingdom (UCL, MEC, and PEF), USA (YUAG), and Germany (DAI). The largest archival repositories are the Library of Congress, YUAG, and UCL; however, relevant photo­g raphs are also located in smaller archives, notably those of Howard Butler and Harry Philby.

Aerial Photo­graphy Many researchers in the study area have used historical aerial photo­g raphy, and the present study made extensive use of this resource.87 A catalogue of relevant pre-WW2 aerial photo­g raphs (APs) is provided in Appendix B. Except for three German APs published by Gustaf Dalman and random images published by modern researchers, the majority are unpublished and held in various archival repositories.88 When available, a combination of vertical or oblique APs and ground photo­ graphy provides a three-dimensional view that aids interpretation. The AP technique was pioneered in the Near East by German archaeo­logist Theodor Wiegand in WW1 in his capacity as Inspector of Monuments in Syria and Palestine under the Turkish administration. 89 Wiegand was followed by Gustaf Dalman, Osbert (Guy) Crawford, and Père Poidebard in the 1920s.90 The RAF flew several AP sorties over Transjordan in the inter-war British Mandate period, and the use of APs also became an established practice in this period by some archaeo­ logists, including Sir Aurel Stein in the Jarash area.91 The first APs of Jarash were taken in WW1 by the German and Australian air forces.92 Only a single photo­ graph of Jarash has been located in the Australian archives; however, the German air force flew at least three sorties in early 1918 that included nine vertical and thirteen oblique photo­g raphs taken at various altitudes.93 With one exception, the vertical photo­g raphs were taken in two separate runs and provide stereoscopic overlap.94 These photo­graphs are generally of good quality and provide a detailed snapshot of the condition of the ruins and landscape just forty years after the estab87 

Stott and others 2018. Dalman 1925, figs  91–93. For more recent examples, see Segal 1981; Kennedy 1998; 2004a: 2004b; Lucke and others 2007. 89  See Gerster and Trümpler 2005, 11–12. 90  See Dalman 1925; Crawford 1929; Poidebard 1934. 91  See Gregory and Kennedy 1985. For an overview of the use of historical aerial imagery in the Middle East, see Bewley and Kennedy 2012. 92  It is likely that the RAF also flew photo­graphic missions over Jarash in WW1 but none have been published and none have been located in archives to date. 93  These photo­g raphs are retained in Berlin, DAI, Archiv der Zentrale, Nachlass Theodor Wiegand. They are listed in Table B1 in Appendix B. 94   For an example of one of the vertical photo­g raphs, see Rattenborg and Blanke 2017, fig. 13. 88 

82  For a description of the history of photo­graphy in Jarash, see Mortensen 2018, 174–78. For the work by Vignes, see Luynes 1874. For photo­g raphs taken by Phillips and Dumas, see Abujaber and Cobbing 2005, figs 55–77. 83  It is generally accepted that the first Circassian refugees arrived in Jarash around 1878 (Kraeling 1938a; Watts 1984; AlSoub, Haddad, and Atiyat 2015); however, Mackey (1979) estimates that the first settlement was as late as 1885. 84   For Bonfils, see Gavin 1982. For Dumas, see Hallote, Cobbing, and Spurr 2013, 49–70. 85  See Abamelek-Lazarev 1897; Schumacher 1902; Libbey and Hoskins 1905. 86  See, for example, Kraeling 1938a.

Information Sources and Methodo­logy lishment of the Circassian village on the eastern side of the city and, importantly, before the modifications to the site brought about by the clearances and archaeo­ logical excavations during the British Mandate period. They, therefore, provide a baseline that, when compared with later photo­graphs, allows changes in the local landscape to be monitored. The Hunting Aerial Surveys (HAS) APs taken in 1953–1954 provide complete coverage of the study area, although they are at a scale of about 1:25,000 and are less detailed than the pre-WW2 photo­g raphs. They formed the basis of the Remote Sensing for Archaeo­logy in the Middle East (RSAME) project initiated by David Kennedy. In the Jarash area, HAS photo­g raphs were analysed in some detail by Kennedy in his studies of the ‘Jerash Basin’ and surrounding areas and, more recently, by the JNWQ team.95 The RSAME project was supplemented by the commencement of aerial photo­g raphic sorties flown in Jordan in 1997 under the Aerial Archaeo­logy in Jordan project, a sub-project of the Aerial Photo­graphic Archive for Archaeo­logy in the Middle East (APAAME) project.96 APAAME commenced taking APs in the Jarash area in 1998, with >4000 APs taken in the study area to date. They are generally oblique photo­graphs taken at low altitudes and are the most detailed in the AP corpus. They are invaluable aids as targeting, recording, and monitoring tools in support of field surveys and provide an unrivalled record of landscape change in the study area over more than twenty years. Satellite Imagery Aircraft and satellite-borne remote sensing is now routinely employed as an interpretational tool in archaeo­ logy and is particularly useful in the assessment of large areas. The study used both publicly available and specially commissioned satellite imagery products. Publicly available colour imagery products with a generally good resolution, such as Google Earth and Bing, were used in conjunction with old black and white APs as aids in interpretation, fieldwork planning, and base map creation. They provide three-dimensional photo­g raph-like images of the earth’s surface on a flexible internet-based GIS platform. Such products have been used before in

95  96 

See Kennedy 2000; 2004a; Stott and others 2018. For APAAME, see Kennedy and Bewley 2009.

21 the Jarash area; the JHS survey, for example, used Google Earth imagery as base maps for field surveys.97 Also, two separate satellite-based commercial imagery packages were acquired to provide the digital surface model and other digital products for use in the study. ALOS World 3D topo­g raphic data (AW3D). Com­ mercially available, high-resolution 2.5  m panchromatic and digital surface model topo­g raphic data were acquired over an area of 584 km2 from AW3D satellite imagery collected between 2005 and 2011. The raw data were processed by Geoimage Pty Ltd to generate 5 m contours and enhancements such as slope and aspect images to aid landscape analysis. Pleiades satellite imagery. Detailed, very high resolution (0.5 m panchromatic; 2 m multispectral) orthorectified satellite imagery was captured from the Pleiades satellite in one swathe of 179  km 2 encompassing the study area on 19 June 2013. The data were processed into images by Geoimage Pty Ltd and used to provide highresolution baseline multispectral coverage to assist in the identification and interpretation of archaeo­logical sites and field targeting.

New Field Surveys The use of new pedestrian field surveys to identify and record water-related installations and infrastructure was an essential empirical element of the overall study. Field survey techniques were applied to parts of the study area in the past, notably by the JHS; however, the present study was the first survey to focus on water-related sites. The technique involved the identification of actual and potential archaeo­logical sites of interest derived from desk-top studies of the literary corpus and visual sources and drawing up prioritized lists of targets to be ground-checked and recorded. The resultant targets were not evenly spread throughout the study area but were generally concentrated downstream of known water sources, usually springs, where localized intensive field surveys were conducted in areas identified as being of particular interest. The survey areas were, therefore, often defined by geomorpho­logical boundaries. Water sources are typically located close to valley floors or in the adjacent wadi banks and lower foothills in the Jarash and Majarr–Tannur valleys, which resulted in intensive surveys being conducted preferentially in these areas; 97 

Baker and Kennedy 2011.

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22

Figure 2.10. Topo­ graphic plan showing the location of Jarash Water Project sites. Five-metre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

Figure 2.11 (left). Location of Jarash Water Project sites in the central part of the study area in their topo­graphical and hydro­graphical contexts. Fivemetre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

less extensive surveys were conducted on the upper valley slopes and upland areas. The author was a member of the JHS team that surveyed the city’s immediate hinterland, and the 114 water-related archaeo­logical sites recorded during that survey formed a useful base for the current study.98 Key water installations recorded by JHS were revisited and, in some cases, reinterpreted and recorded in more detail. No archaeo­logical excavations were attempted during the study apart from occasional small test pits allowed under the DOA survey permits. The field survey methodo­logy employed was generally similar to that employed by JHS, with the additional intensive use of historical photo­g raphs and total station surveying of selected sites. Walkover field surveys were conducted along traverses, and intensive walkover surveys were conducted in specific localities or areas of archaeo­logical interest identified from photo­graphic and 98 

2011.

See Kennedy and Baker 2009; Baker and Kennedy 2010;

Information Sources and Methodo­logy

23

Figure 2.12. Chart showing the breakdown of structural types recorded during the study (n = 172).

satellite imagery analysis. At each new archaeo­logical locality, the main features were measured, recorded onto plans and Mega-Jordan field sheets, and photo­g raphed digitally. Field sketches were drawn, and the physical location of each locus was determined by a hand-held Garmin GPS instrument to an accuracy of 4 to 6 m, and total station surveys were conducted at twelve sites of particular archaeo­logical interest.99 Sherd and flint lithic materials were collected at several sites, and samples of mortar, plaster, and carbonate deposits were collected from water installations for further analysis and dating. Geo­logical and landscape data were also noted. Data were entered into an Excel spreadsheet-based database that recorded site type, location, photo­g raphic reference, and samples collected. Site details are presented in Appendix C. Archaeo­logical structures from ninety sites ( JWP102– 192) were recorded during four seasons of the ground survey. Nine main structural types were identified during the survey, and the results are listed in Table C1 in 99  

These sites were JWP114, 140, 142, 145–48, 156, 164, 177–78, 183.

Appendix C.100 Site locations are identified in Figures 2.10 and 2.11, and a chart showing the breakdown of the main structural types recorded at these localities is presented in Figure 2.12. The use of less-intensive surveys over parts of the study area means that the study did not capture every recordable water installation; however, the coverage was sufficient to ensure that the recording of visible remnants of the larger water installations (i.e. the main conduits, reservoirs, and basins) was comprehensive in key parts of the Jarash and Tannur valleys. The small number of cisterns recorded in the field survey certainly does not reflect the total number of cisterns in the study area observed on the ground and from APs and satellite imagery. The study focused on water management prior to ad 750; however, water-related installations can be difficult to date from observation alone, and, in practice, all such installations were recorded in the field unless they were obviously modern constructions. 100 

Two sites ( JWP193–94) were added during the course of data compilation.

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24

Terrestrial Carbonate Studies Background

Terrestrial Carbonates in Natural Settings Spring tufa and speleothems are examples of terrestrial carbonate deposits that precipitate from karst water sources in natural settings. Samples were collected during the JWP field survey as these materials may be amenable to radio­carbon dating and are potentially a source of palaeoclimate proxy and geohydro­logic data. Water in karstic aquifers contains carbon dioxide (CO2) and dissolved calcium carbonate. When calcium carbonate-saturated water emerges into the atmosphere, the CO2 is removed, a process that is known as degassing, and the dissolved carbonate precipitates on surfaces as tufa.101 The amount of tufa deposited depends on factors that include temperature, amount of dissolved carbonate, and the speed of CO2 degassing, so that rapid degassing — as occurs in cascades and waterfalls — will result in greater thicknesses being deposited.102 The tufa cascade in central Jarash described in Chapter 6 is a good example, but tufa is more typically found as minor encrustations around spring outlets in the study area. Speleothems are formed from calcium carbonate-saturated drip-water in caves and voids above the water table, and the only known speleothem locality in the study area is the tufa cascade in Jarash. Kurnub sandstone is a quartz arenite that typically contains no primary calcium carbonate, and the presence of tufa at springs that emerge from this formation, such as at the Ficus Springs and Shallal localities in the lower Jarash valley, is attributed to hydraulic connectivity with overlying Na’ur limestone or Jarash Conglomerate formations.

Terrestrial Carbonates in Artificial Settings Calcium carbonate may also precipitate on the internal walls of aqueducts and other constructed installations supplied from karstic springs, where it forms laminated deposits known as carbonate sediment.103 Much of the palaeoenvironmental research into terrestrial carbonates to date has focused on laminated speleothems, especially 101  Spring tufa is also referred to as sinter or travertine in some publications. 102  See Ford and Pedley 1996, 117–18. 103  Carbonate sediment is known as calcareous sinter in some publications.

stalagmites, but recent research has highlighted the potential of laminated carbonate sediments in Roman aqueducts as a valuable source of climate proxy and other environmental data. Compared to speleothems, flow rates in aqueducts are more substantial and more continuous. The carbonate sediments accumulate rapidly and are often well laminated, and the thicker laminae offer the potential of higher-resolution data analysis compared to the generally thinner laminae in speleothems. This, together with the relatively controlled flow regime within an aqueduct, makes carbonate sediment an attractive research focus. Research of Roman aqueducts around the Mediter­ ranean region has shown that many contain carbonate sediment.104 Several aqueduct sites have been studied in some detail, including a very recent study on a Jarash aqueduct ( JW01) identified by the JWP.105 Carbonate sediment is rarely preserved in aqueducts in the study area, and JW01 is the only aqueduct to date from the Classical period found to contain hard, coarsely laminated carbonate sediment.106 Carbonate thickness generally decreases with distance from the source owing to the gradual dissipation of contained CO2, but rapid CO2 degassing due to water turbulence in aqueducts with steep gradients will generally create thicker deposits, even some distance downstream of the source as in the case of several sites along aqueduct JW01. The overall steep gradient and the propensity for turbulent flow conditions in JW01 probably account for the thicker development of carbonate lining this aqueduct compared to others in the study area.

104 

Sürmelihindi and Passchier 2013, 270. For the Jarash study, see Passchier and others 2021. For aqueduct sites in France, see Garczynski, Foucras, and Dubar 2005; Levret and others 2008; Volant and others 2009; Bobée and others 2011; Sürmelihindi and others 2018; Benjelloun and others 2019. For aqueduct sites in Italy, see Carlut and others 2009; Keenan-Jones and others 2015. For aqueduct sites in Turkey, see Sürmelihindi and others 2013a; 2013b. 106   Carbonate sediment was found at all six sites recorded along aqueduct JW01, but was best-preserved at site JWP128. Thin deposits of finely laminated porous carbonate sediment were noted on several channel blocks of aqueduct DW01 and in a Birketein reservoir channel outlet. The study also found carbonate sediment lining the arubah (a vertical, cylindrical plaster-lined water tank) in the penstock tower of several watermills in the Jarash valley that likely date to the Middle Islamic period. 105 

Information Sources and Methodo­logy Materials and Methods

Tufa Samples of spring tufa were removed from cleaned surface outcrops using a hammer and chisel and placed in sealed, airtight plastic bags. Two samples from site JWP177 on the tufa cascade on the east bank of the wadi in central Jarash were submitted for radio­carbon (14C) AMS carbonate dating as part of an ongoing JWP study embracing the archaeometric and palaeoclimatic proxy potential in local freshwater carbonates.107

Carbonate Sediment Research on laminated carbonate sediment in aqueduct JW01 and other Roman aqueducts has focused on high-resolution studies of stable isotopes δ13C and δ 18O and trace elements coupled with petro­g raphic studies. In the case of aqueduct JW01, laminated carbonate sediment at site JWP128 was found in discrete depositional sequences separated by plaster layers in a secure strati­graphic context. In the field, the surfaces of the laminated carbonate were cleaned, and vertical sections of the carbonate strati­graphy were photo­graphed, annotated to show orientation, removed using a hammer and chisel, and placed in sealed plastic bags. In the laboratory, the sections of carbonate were sawn in half using a diamond saw. One half was used for thin and polished section preparation, and the other half for laboratory analysis. Stable isotope samples were collected over intervals of 0.2 mm along a micro-milled track cut into the surface of the slab and analysed using an isotope ratio mass spectrometer. Trace-element samples were collected at intervals of 300 μm along a parallel track to the stable isotope samples and analysed by the laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) technique.108 The results of the study are discussed in Chapter 6. Absolute radio­carbon dates were obtained from samples of the plaster layers separating the carbonate sediment sequences.109

Other Materials Speleothems were identified in a cave and voids in the exposed tufa cascade on the eastern wadi bank in central 107 

Samples B-425329 and B-425330. See Appendix D. Detailed analytical methods and results are provided in Passchier and others 2021. 109  The results are listed in Appendix D, Table D1. 108 

25 Jarash. A 47 cm long stalactite fragment was recovered from the cave for later scientific study. Terrestrial molluscs also contain calcium carbonate and are a potential source of palaeoenvironmental proxy data, and can potentially be radio­carbon dated.110 Bivalve and gastropod mollusc shells were identified in plaster used in water installation construction and in spring tufa at a total of twelve sites, and samples were taken for future schlerochrono­logical and palaeoenvironmental study.

Archaeometry Overview It is highly desirable to be able to establish the chrono­ logy of the water installations identified in the study. Many of the urban water installations recorded in the published corpus were found in strati­g raphic contexts that permitted the dating of their construction and use through the application of ceramic typo­logy, although it is not always possible to confirm the security of these contexts from the available evidence. Installations can also be dated from inscriptions, and examples include the dedication of the Nymphaeum (ad 190–191) and fountains on the Cardo (mid-second to the early third centuries).111 The only water installation outside the city that was dated prior to the present study was the Birketein reservoir, the largest water installation in the study area, which had an early third-century terminus ante quem deduced from an inscription dated to ad 209–211 on a column fragment.112 There are several potential options available for the absolute dating of structures and depositional sequences, although all are subject to limitations. Radio­carbon dating of organic and carbonate materials is a widely used and cost-effective method and was adopted in the present study whenever datable materials were found. However, datable materials were not commonly found associated with water installations from the study period. The aqueducts outside the city are particularly challenging as they do not lie in strati­graphic sequences amenable to ceramic dating in the majority of cases, but are cut into surface 110 

See Pigati, Rech, and Nekola 2010. For the dating of the Nymphaeum, see Welles 1938, 406, no. 69. For the dating of the Cardo fountains, see Seigne 2008, 49. 112  Welles 1938, 428, no. 153. The column fragment was found in a secondary context but is supposed to have come from a column that formed part of a colonnade around part of the reservoir. 111 

Chapter 2

26 bedrock and have either bare, exposed internal bedrock surfaces or are filled with transported materials in insecure contexts. Where preserved, organic carbon (usually charcoal) embedded in lime-based plasters and mortars was radio­carbon dated, and a small number of charcoal samples were recovered from depositional sequences. The radio­carbon dating of lime plasters, mortars, and terrestrial carbonates is also possible in some circumstances and is discussed further below.113 The dating of lime plasters is an important consideration because of the potential to identify the construction or repair date of the installation. The OSL dating technique has been widely applied in the dating of suitable quartz or feldspar grains in unconsolidated materials, and there are several examples of unconsolidated sediments associated with water installations being dated using this technique.114 The archaeo­logical environment of the majority of extramural aqueducts in the study area — i.e. unburied canals cut directly into surface bedrock — is not amenable to the application of the OSL technique.115 The application of the technique to hard materials such as plasters and mortars presents challenges.116 Several successful examples of the OSL dating of single quartz grains in mortars and plasters have been reported from sites in Europe; however, the application of this technique is not yet widespread.117 The U-Th radiometric technique has been attempted elsewhere to date carbonate sediment lining Roman aqueducts, where it was found to be generally unsuccessful due to poor resolution.118 The technique is prone to problems related to low initial uranium concentrations and contamination from detrital thorium. The technique has been applied more broadly to the dating of tufa but

113 

A pilot JWP 14C AMS dating study of lime lumps and lime plaster was conducted with the assistance of ANSTO (see Boyer 2019, Appendix F). Mortar dating was applied at several sites in the city’s North-West Quarter by the JNWQ (Lichtenberger and others 2015) but the majority of JNWQ radio­carbon dates were obtained from charcoal (Philippsen and Olsen 2020). 114  For an example from South America, see Aiuvalasit, Neely, and Bateman 2010. 115  The OSL technique is potentially applicable to later earthen canals from the Middle Islamic–Ottoman period, but such a study remains a desideratum. 116   See Urbanová and Guibert 2017; Urbanová and others 2018. 117  Guibert and others 2020. 118  See Wenz and others 2016.

with mixed results.119 Further research is needed to see if locally sourced materials have the necessary chemical criteria to produce reliable U-Th isochrons. Radio­carbon Dating The results of thirty-three AMS dates from the radio­ carbon dating programme are reported in Appendix D (Table  D.1).120 Organic materials were dated in the majority of cases; however, three samples of bulk lime plaster, two samples of terrestrial carbonate, and one sample of carbonate sediment were also dated using conventional pretreatment and AMS protocols. Organic materials can be dated using the conventional radiometric method or the AMS method, depending on sample size, but the small quantities of organic material in plaster and mortar samples meant that only the radio­carbon AMS (14C AMS) dating method could be employed on the JWP samples. The lime binder material in mortar samples frequently contains limestone contamination, which makes reliable 14C AMS dating of lime mortar almost impossible unless lime lumps can be extracted and dated separately.121 In addition to the thirty-three samples mentioned above, a pilot 14C AMS dating programme using a modified hydrolysis protocol was conducted by ANSTO in Australia on three lime lump samples and eight bulk plaster samples.122 The results from seven samples were unacceptable due to limestone contamination, while three samples (two lime lump and one bulk lime plaster) produced inconclusive results, and the programme was discontinued.123 Samples containing organic material were, therefore, preferentially selected for 14C AMS dating. Where there was sufficient datable 119  For examples of the U-Th dating of tufa, see Garnett and others 2004. 120  AMS dates from sites JWP114 and JWP128 were previously reported in Passchier and others 2021 (supplementary data S3). 121  This problem was identified in 14C dating studies conducted on mortar samples from the city’s North-West Quarter: see Lichten­ berger and others 2015. For a detailed review of mortar sampling issues, see Daugbjerg and others 2020. The presence of limestone contamination in lime plasters is demonstrated by the pre-Holocene dates obtained from sites JWP 142 and 164. 122  The modified hydrolysis protocol includes the collection of multiple CO2 samples and follows the procedure in Heinemeier and others 2010. 123  See Boyer 2019, appendix F. The financial support from the Centre for Accelerator Science at ANSTO through the Australian National Collaborative Research Infrastructure Strategy (NCRIS) is acknowledged in connection with Project N10082.

Information Sources and Methodo­logy material, two samples were dated from each sampling site. The dating of such materials has been reported from many sites in the city’s North-West Quarter and from several sites in southern Jordan.124 Samples of dry, unweathered materials were collected in the field using a hammer and chisel and placed in sealed, airtight plastic bags. Samples were inspected under a binocular microscope, and, where possible, organic material was separated prior to shipment to the dating laboratory, but some bulk samples containing friable organic material were also shipped for pretreatment. The quantity of friable organic material in several samples was found to be insufficient for dating after pretreatment. Samples were shipped to either the Beta Analytic laboratory, Miami (B-prefix) or the Waikato Radio­ carbon Dating Laboratory, Hamilton, New Zealand (Wk-prefix) for AMS radio­carbon dating. At both laboratories, each sample was subjected to conventional laboratory ABA pretreatment. Conventional Radio­carbon Age results from both Beta Analytic and Waikato have been calibrated into calendar years using the IntCal 20 atmospheric curve and the online OxCal v4.4.4 calibration program. 125 Plots for the twenty-seven AMS radio­carbon dates for organic samples are presented in Appendix D (Fig. D.1), and the results are discussed in relevant sections of the text.126 The 14C AMS date of organic inclusions and the construction date of the installation may not be coincident because of what is known as the ‘old wood’ effect, due to the age of the wood used to make the charcoal and the possibility of delayed use and reuse of the wood prior to carbonization. Some species, such as olive trees, are longlived, and their age may exceed one hundred years. The fragments of carbonized material in the samples were often found to be too small for reliable species identification. Where possible, short-lived material such as olive pits or twigs was selected for dating, although choice was usually limited by the small amount of available organic material. Charcoal samples were collected from the base of poorly consolidated gravel sequences at sites located on 124  For results from the North-West Quarter, see Lichtenberger and others 2015; Philippsen and Olsen 2020. For results from southern Jordan, see Al-Bashaireh 2013. 125  For IntCal 20, see Reimer and others 2020. For the OxCal calibration program, see Bronk Ramsey 2017. 126  AMS dates from sites JWP114 and JWP128 were previously reported in Passchier and others 2021 (supplementary data S3).

27 the Artemis upper terrace and Birketein to constrain the timing of the gravel deposition. These gravels are redeposited material collected from the ground surface during high-intensity rainfall events. Whilst the samples were recovered from an in situ stratified context, the possibility that the charcoal may have been ‘old’ charcoal lying in the soil prior to the gravel deposition event means that it may yield a date older than the gravel event. Radio­carbon AMS dating of carbonate was also conducted on two tufa samples from the relict tufa cascade in the centre of Jarash.127 Uncertainty can arise in the dating of tufa carbonate from factors that include the socalled freshwater reservoir or ‘hard water’ effect and contamination from secondary calcite crystallization from groundwater. The hard water effect has the potential to make the sample result appear older than it actually is due to the inclusion of dissolved calcium carbonate from older limestones through which the karst water passes.128 Secondary calcite crystallization has the potential to make the sample age to be older or younger than its actual age, depending on its provenance. The age difference may be in terms of hundreds or several thousands of years.129 The low strati­graphic position of the sample site at the base of the tufa cascade means that secondary calcite crystallization may be contributing to the age of sample B-425330.

127 

The results are presented in Table D.1, Appendix D. For a discussion on the freshwater reservoir effect, see Philippsen 2013. 129  See the discussion on recrystallization contamination in Lindroos and others 2007 and Nonni and others 2018. 128  

Figure 3.1. Contour map of the study area showing the disposition of the plateau segments within the eroded terrain. Five-metre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

Colour Plate 1. Slope map of the study area. Five-degree slope classes by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

Chapter 3

Natural Environmental Contexts

T

his chapter investigates the physio­graphic contexts to gain an understanding of the background to the water management system’s creation, the nature of the physical landscape in which it was constructed, and changes to the landscape over the study period.1

Physio­graphy and Geomorpho­logy Topo­graphy and Relief The ancient city lies in the south-eastern foothills of the Ajlun uplands within the ‘highland’ physio­g raphic region described by Al-Bilbisi.2 Using the definitions outlined in the MEDSCAPES LCA protocol, the topo­ graphy of the northern highlands comprises a dissected upland formed over uplifted Cretaceous limestone basement rocks and is bisected by the Zarqa River valley.3 A contour plan of the study area shows it to be an eroded upland plateau that is divided by the main wadi drainages into several plateau segments (Fig. 3.1). Within the Jarash valley, the Wadi Suf/Wadi ed Deir/ Wadi Jarash drainage separates the northern and central plateau segments and the hills of the central watershed (central hills) from the eastern plateau in the Majarr– Tannur valley. The overall drainage pattern is dendritic, but there is significant spatial variation in the level of wadi incision, with the plateau segments being more deeply dissected by tributary wadis north of 32.31 N and south of 32.26 N. The periodic rejuvenation of wadi erosion is evidenced by knickpoints in the beds of the principal wadis. Knickpoints represent the upstream extent of headward erosion resulting from recurrent base-level changes related to regional structural uplift events in the Tertiary and Quaternary periods and are the sites of active or relict waterfalls (see Figure 3.1 for location).4 1  For overviews of the physio­graphic contexts, see Boyer 2018a; 2018d. 2  See Cordova 2007, 32; Al-Bilbisi 2013, fig. 1.3. 3  The MEDSCAPES LCA protocol is outlined in Abu-Jaber and others 2015. 4  The most significant waterfall today is at the Shallal locality in

At least four phases of wadi rejuvenation can be identified in the Jarash valley. Overall, the topo­g raphic relief can be described as undulating. Slope analysis shows that slopes over the plateau remnants and valley floors are generally gentle (25°) are found on some lower wadi slopes (especially Wadi Tannur, southern Wadi Jarash, and parts of Wadi Suf ) and the northern watershed areas. Palaeolandscape History

Overview The analysis of field evidence provides insights into the area’s geomorpho­logical history and an understanding of its diachronic evolution, although absolute dating is currently lacking for many events.5 The last major preHolocene sedimentation event in the study area was the deposition of the Jarash Conglomerate that is described below. 6 The Jarash Conglomerate was deposited in the ancestral Jarash valley that had been incised into a weathered Upper Cretaceous limestone plateau in earlier erosive cycles. This plateau had been modified by faulting and structural flexing in the Eocene–Oligocene periods.7 The erosion of the flat-lying Cretaceous strati­ graphy highlights the variability in the hardness of the layers, resulting in the creation of many natural terraces Wadi Jarash, 2.1 km south of the city, which has an estimated height of 20–25 m, but the relict cascade above the modern Maghasil spring at Suf may have been higher. 5  Boyer 2018a; 2018d. 6   This event has not been accurately dated but a tentative correlation with the Dawqara Conglomerate in the upper Zarqa River area based on similarities in litho­logy, landscape setting, and the presence of flint lithics, suggests an early Pleistocene terminus ante quem. Scardia and others (2019, 12) considered that ‘A weighted mean age of 1.98 ± 0.20 Ma is considered the best estimate of the caliche formation and represents an ante quem chrono­logic constraint for the Dawqara Fm’. 7  Abdelhamid 1995, 31.

Chapter 3

30 and a ‘stepped’ or ‘benched’ landscape profile. One or more phases of calcretization established a calcareous duricrust on top of the bedrock. Calcretization of the Jarash Conglomerate resulted in the creation of distinctive sheet-like landforms of exposed duricrust that drape the lower slopes of the main valleys and form prominent terraces at Khirbet esh Shawahid and Bab Amman in the Jarash valley. Evidence of post-depositional structural deformation was observed in outcrops of Jarash Conglomerate at Bab Amman, and later earth movements resulted in brittle fracturing of the calcrete duricrust along the wadi flanks and the creation of multiple scarps and landslips on the steeper slopes. Low and mid-level terraces in the southern Jarash valley are the benchtops of ancient landslides. The palaeolandscape underwent erosion subsequent to the deposition and calcretization of the Jarash Conglomerate. Base level changes resulted in deeper erosion in Wadi Suf, southern Wadi Jarash, and Wadi Tannur, which is reflected in the steep slopes associated with these wadi sections. The erosional conditions described above also impacted the palaeolandscape at higher elevations, as evidenced by the incision of runoff gullies into bedrock along the western and eastern watersheds of the Majarr–Tannur valley. The erosion took place under pluvial climatic conditions and would have been accompanied by strong runoff and attendant soil erosion and strong flows from springs supplied from recharged aquifers. The timing of pluvial events is unknown but may date to a Palaeolithic pluvial period, and the establishment of the major groundwater discharge sites at Suf, the city area, Ficus Springs, and Shallal in the Jarash valley may also date to the same events. Palaeohydro­logical details are lacking, but it is supposed that these flows, in turn, would have established a strong surface flow regime in the wadis that, when combined with the valley gradients, would have kept the valley floors essentially free of sediment. This flow regime would have varied with the seasons, but the combined flow would have made the combined Jarash and Majarr–Tannur valleys a significant tributary to the Zarqa River. The strong overland flows would have also triggered landslides in susceptible areas and dumped colluvial sediments into the wadis, but the prevailing flow regime would have prevented these sediments from accumulating in the wadis. Subsequent climatic change reduced runoff and spring flow, and ultimately many previously strong springs dried up as a result of lowered water tables. The timing of this significant climatic change is uncertain, but the working hypothesis is that it followed the end

of the early Holocene wet phase around 5050 cal bc (‘7 cal. ka bp’).8 The geomorpho­logical history of the study area in the period between the fifth millennium bc and the Hellenistic period is very uncertain. Studies in Wadi Ash-Shallaleh east of Irbid found evidence for an aggradation phase in the fourth millennium bc that was followed by a stream incision phase between c. 2550 bc and c. 2050 bc.9 It remains to be determined if contemporaneous events prevailed in the study area, but evidence of an entrenched wadi incision phase that removed preexisting rock-cut canals at the Ficus Springs locality (site JWP146) south of the city may reflect the third-millennium bc wadi incision phase recorded in Wadi AshShallaleh.10 Notwithstanding the end of the Holocene wet phase, the city’s appellation ‘Antioch on the Chrysorrhoas’ implies that strong perennial wadi flow continued into at least the Hellenistic period, and there is photo­graphic evidence of a good flow over the southern watergate waterfall into the first quarter of the twentieth century.11 The subsequent change in the flow regime that resulted in the accumulation of sediments in the main wadis is discussed further below in the context of recently published OSL dates of wadi sediments.12 Based on the above, the final stages of the significant erosional developments in the landscape visible today were being established during the Neolithic occupation of Tell Abu Suwwan, which lasted from the late ninth millennium cal. bc until at least the early sixth millennium cal. bc.13 The landscape would have seen many topo­graphical and vegetative changes in response to changes in the climatic regime in the subsequent period up to the second century bc. Increasingly from the Neolithic period, there would have been landscape 8 

Robinson and others 2006, 1536–37. Cordova 2008, 443. 10   A preliminary review of the landscape history of Ficus Springs appeared in Boyer 2018d (68–70); however, new evidence subsequently came to light and the palaeolandscape study of this site is the subject of ongoing research. The rock-cut canals at site JWP146 are described in the aqueduct catalogue in Appendix G. 11  For images of water flowing over the south watergate waterfall in the twentieth century, see photo­g raphs LC-DIG-matpc-05344 and LC-DIG-matpc-06463 (Washington, D.C., Library of Congress Matson Photo­graphic Collection) and photo­graph GX17 (Greifswald, Institut Greifswald Gustaf Dalman Collection). 12  See Holdridge and others 2017; Cresswell and others 2018; Lichtenberger and others 2019. 13  For descriptions of the Tell Abu Suwwan site, see Al-Nahar 2006; 2010; 2013b; 2018. 9 

Natural Environmental Contexts

31

modifications resulting from new farming practices, and the redirection of spring flows to agricultural and urban use in later periods further reduced the perennial flow regime in the main wadis. The effects of post-Early Islamic landscape changes need to be taken into account when considering the nature of the landscape in the study period. While historical ground and aerial photo­graphy can assist in informing an interpretation of the area’s palaeolandscape history, only data from archaeo­ logical excavations can yield proof, and these proofs are currently confined to the west side of the city and to several points in the Jarash valley.

Palaeolandscape of the City The palaeolandscape history of the city has only recently attracted academic attention.14 The city area occupies the lower slopes of a hilly terrain that stretches beyond the city walls. The cityscape is dominated by hilltop spurs that project into the Wadi Jarash valley, separated by wadis (Fig.  3.2) — the most significant being the Figure 3.2. Map of the location of wadis in the city area in the pre-Roman period. north-west wadi and the eastern Adapted from Stott, Raja, and Lichtenberger 2019. wadi — and a substantial natural terrace on the lower east side or moderate.15 A major fault backscarp on the eastern of the city (henceforth eastern lower terrace) (Fig. 3.3). side of the wadi separates the eastern lower terrace from Evidence presented below shows that these spurs an upper terrace (henceforth, eastern upper terrace). were bounded by angular fault escarpments in Antiquity, although today, the slopes are, for the most part, gentle Headward erosion following a base level change established a major knickpoint in the bed of Wadi Jarash on the site of the city’s southern watergate, and a second less 14  For brief commentaries, see Seigne 1992; 1997a; 2002b; significant knickpoint was probably established at the Parapetti 2007; Lichtenberger and Raja 2016a, 99–101. For site of the northern watergate in the city wall. The wateran overview of the history of human interaction with the palaeolandscape, see Boyer 2018a. For a description of the key landscape components, a diachronic view of landscape changes, and discussion of the impacts of these change on settlement patterns, see Boyer 2018d.

15 

For a description of the formation of the escarpments. see Boyer 2018d, 63–64.

Chapter 3

32

Figure 3.3. Diagram showing the location of key topo­graphical landscape features in the city area. Drawing N. Ellis.

fall site at the southern watergate is currently c. 10 m high but was likely at least 15 m high before the plunge pool below it was filled with wadi sediments.16 The smoothing of the landscape since the Roman period has come about for two reasons: firstly, excavations have shown that virtually the entire western side of the city is mantled by colluvium that buries or obscures the pre-existing landscape; secondly, the original topo­ graphy was locally modified in the Early Roman period by artificial benching, infilling, and the construction of terraced platforms. The hilltop spur in the city’s North-West Quarter is the most significant landform on the western side of the city and formed an integral part of the Early Roman city plan. Recent excavations in the North-West Quarter by the JNWQ team have shown that the northern edge of this spur was marked by an escarpment, and an escarpSchumacher (1902, 119) recorded a waterfall height of 10.5 m at the end of the nineteenth century. The estimated original height is taken from the existence of a buried watermill arubah beside the plunge pool; arubah are constructed within penstock towers that are typically 4–6 m in height (see Avitsur 1960). This is the lowermost mill in a complex of at least three watermills established on the wadi bank at this location.

ment also marked its southern edge where it forms the north wall of the Bishop Genesius Church.17 Karstic cascade springs were established on these escarpments early in the area’s landscape history; the escarpments gave the hills greater prominence, enhancing their usefulness as high-visibility locations for high-status buildings such as temples and churches.18 The north-western spur was the site of the cella of the Artemis Temple, which was placed on a projecting natural terrace on its eastern side, and both spurs on the western side of the city were used for the placement of critical water infrastructure. The most significant landform on the east side of the city is the north-eastern spur with Qairawan spring at its foot. Today, the southern edge of this spur is marked by a scarp; however, in the study period, the scarp was even more prominent and extended southwards, where it would have formed a natural constraint to the spread of settlement on this side of the wadi.

16  

17 

Kalaitzoglou, Lichtenberger, and Raja (2013) reported a 6.5 m high cliff in trench ‘H’ to the south of the supposed alignment of the North Decumanus. 18  Byzantine churches are located at high points on all the hilltop spurs within the city.

Natural Environmental Contexts

Figure 3.4. Climate classification map. Inset shows the study area in more detail. Adapted from Beck and others 2018. CC BY 4.0 [accessed 1 December 2021].

There is archaeo­logical evidence at several locations on the city’s west side that the Roman engineers were prepared to modify the existing terrain to suit their plans. The upper and lower terraces of the Antonine Artemis Sanctuary were earthworks constructed on the north-western spur, and the eastern end of this spur was benched to accommodate the construction of the Cardo and the West Propylaeum façade.19 To the south, the wadi immediately west of Camp Hill was filled to a depth of at least 8 m to accommodate the Oval Piazza. Even though the archaeo­logical evidence is currently missing, it is reasonable to assume that a similar level of consideration would have gone into planning the major constructions on the east side of the city.

propylaeum on the west side of the Cardo leading up to the Artemis Sanctuary is referred to as the West Propylaeum, to distinguish it from the propylaeum facing it on the east side of the Cardo, which is referred to as the East Propylaeum. For a crosssection through the Artemis lower terrace, see Brizzi 2018, fig. 6.13. 19 The

33

Climate Modern Climate The climate is typified by wet winters and warm, dry summers, but elevation and topo­g raphy create significant local variations. Using the latest Köppen-Geiger climatic classification map published by Beck and others, the study area straddles several climate zone boundaries (Fig. 3.4).20 The northern half, including the Jarash valley upstream of the city, lies in the ‘temperate-dry summer Mediterranean zone’ (‘CSa’), the southern Jarash valley lies in the ‘Arid-steppe cold’ zone (‘BSk’), with mean annual temperatures 18° C. Between 1950 and 2008, Jarash’s annual rainfall averaged 355.72 mm.21 Annual rainfall, however, reduces rapidly eastwards from the Ajlun Mountains, averag20 

Beck and others 2018. This compares with average rainfall of 303.7 mm in the period 1937–1992 (Zaid 1997, table 2) and average rainfall of 372.4 mm at Jarash Bridge Gauge Station in the period 1980–2013 (Shammout and Abualhaija 2019, 3044, table 1). 21 

Chapter 3

34

Figure 3.5. Average rainfall map based on data from 1977. From Ababsa 2013, fig. I.12. © Presses de l’Ifpo, 2013. Reproduced with the permission of Ifpo.

Figure 3.6. Bar chart showing Jarash rainfall in the period 1942–2008. Drawn from data in Al-Qaisi 2010.

Natural Environmental Contexts

35

Figure 3.7. Jerash Bridge Weather Station data 1980–2013. (a) Bar chart showing total rainfall; (b) Scatter plot chart showing the relationship between total annual rainfall, the number of rain days, the average rainfall per rain day, and the trend line of rainfall per rain day. Drawn from data in Shammout and Abualhaija 2019.

ing 543.35 mm at Kitta 4 km west of Jarash and only 220.47 mm at Medwar 10 km east of Jarash, resulting in a 150–200 mm variance in annual rainfall across the width of the study area (Fig. 3.5).22 The rainy season occurs between October and April, with 80 per cent of annual rainfall typically falling between December and March.23

22  Data from Al-Qaisi 2010, table.11.1. See also Boyer 2018a, 224; 2018d, 62. 23  Al-Shorman, Al-Bashaireh, and Bani Doomi 2011.

There are two main influences on the amount and reliability of the rainfall in the study area. Firstly, the number, intensity, and track of rain-bearing depressions from the Eastern Mediterranean that cross the Ajlun Mountains and, secondly, oro­g raphic effects that result in a rapid reduction in rainfall with increasing distance eastwards. The Ajlun Mountains lie close to the typical northerly track of the rain-bearing depressions, and annual rainfall decreases southwards with increasing distance from this track.24 Figure 3.6 shows the significant year-on24 

For commentary on the Jordanian climate, see Shehadeh

36 year variation in annual rainfall for Jarash in the period 1942–2008, and Figure 3.7a shows the annual rainfall for the weather station at Jerash Bridge on the Zarqa River for the period 1980 to 2013.25 Rare extreme weather events are a feature of the present climate, and evidence presented in Chapter 10 suggests that such events were more prevalent in the Byzantine period. Zaydoon Zaid studied Jarash rainfall records for the period 1937–1992 and found that while rainfall intensities >25 mm/day occurred on only 8 per cent of rainy days, or around five days per year on average, these events contributed 32.4 per cent of the total rainfall.26 Zaid found that the average number of rain days per year between 1937 and 2008 was 52, which compares with an average of 37.6 rain days between 1980 and 2013 recorded at the Jerash Bridge.27 The data from the Jerash Bridge station shows a weak relationship between total annual rainfall and the number of rain days and, with few exceptions, rainfall intensity (average rainfall per rain day) is relatively constant at c. 8–12 mm/rain day (Fig. 3.7b). Palaeoclimate An understanding of the climatic conditions that prevailed during the study period is integral to understanding the environment in which the water management system operated. The timing, frequency, and intensity of the rainfall, the duration of the wet season, and the amount of evaporation determined the water table levels and the quantum of water available to recharge the aquifers that supplied the springs. These were critical factors in the success or failure of the local agricultural economy down the ages. However, climatic considerations need to go back even further in time. The main physical landscape features were established by the end of the early Holocene, and the use of the spring sources and other elements of the area’s water management system probably had their foundations in the prehistoric period. There have been considerable advances in recent years in regional Levantine palaeoenvironmental studies based on the analysis of various proxy data.28 However, 1985; Ababsa 2013, 64–67. For a description of climatic mechanisms in the Levant, see Kushnir and others 2017. 25  For the Jarash Bridge weather station date, see Shammout and Abualhaija 2019, 3044, table 1. 26  Zaid 1997, 35. 27  Shammout and Abualhaija 2019, 3044, table 1. 28  For a summary of results from various studies, see Robinson and others 2006; McCormick and others 2012. For commentary

Chapter 3 with few exceptions, these studies are confined to sites within or to the west of the Dead Sea/Jordan valley, with a marked concentration in the Dead Sea/Lake Lisan/ Lake Kinneret basin.29 While regional studies span the period up to c. 400,000 bc, the majority relate to the Holocene period.30 The resolution of the studies has been steadily improving, but the results have so far failed to deliver a comprehensive understanding of the region’s palaeoclimatic history.31 There are apparent differences in the pre-Holocene reconstructed palaeoclimatic histories between the northern and southern Levant: in the northern Levant, humid phases coincide with interglacial periods, whereas the opposite is the case in the Dead Sea region. There is also variability in high-resolution results within the Dead Sea basin, which may reflect differences in elevation, oro­g raphic effects, the impact of the north–south climatic gradient established in the Levant since the last glacial period and tropical climatic influences in the southern Levant. 32 It is concluded that the Levantine studies point to a number of wetter climatic periods in the Palaeolithic period between 248 and 48 ka bc and between 8 ka and 5 ka bc in the Holocene period.33 In the Near East context, a common theme among palaeoclimate researchers is that climatic change contributed to the decline of the Roman and Byzantine Empires, but there is disagreement concerning the actual research findings. There is also a tendency to compare high-resolution proxies (from speleothems and other sources) with low-resolution Dead Sea level data. Orland and others showed that annual rainfall declined overall from c. 2100 bp to c. 700 bp,34 but other studies show on Levantine climatic reconstructions from speleothems, see BarMatthews and others 2017. 29  For a list of speleothem sites, see Burstyn and others 2019, 3–4, table 1. 30  The longest high-resolution records come from pollen studies. Miebach and others (2019) studied a continuous pollen record in a Dead Sea core from c. 88,000–14,000 bp, while Gasse and others (2015) studied a discontinuous core record from Yammouneh in the northern Levant from c. 400,000 bp. 31  For general discussion on the region’s palaeoclimatic history, see Enzel and others 2003; 2008. 32  For a discussion on climatic gradients, see Rambeau 2010. 33  Bar-Matthews and others 2017, 159. Robinson and others (2006, 1535–37) noted that ‘The early Holocene [c. 9.5 to 7.0 cal ka bp] appears to have been the wettest phase of the past 25,000 years across much of the Levant and eastern Mediterranean’ (i.e. since the last glacial maximum). 34  Orland and others 2009.

Natural Environmental Contexts that there was significant rainfall variability within this date range. The results presented by Rambeau and Black suggested that the period of Hellenistic colonization of the Decapolis coincided with the onset of wetter climatic conditions that persisted, with periodic variations, until around the sixth century. Within this period, sharp reductions in rainfall occurred around ad 100 and in the mid-fourth century.35 McCormick and others broadly agreed, based on Dead Sea levels, and concluded that The Roman and late Roman periods were separated by a low stand. The high stands provide a strong signal of increased precipitation in the Levant. The first Roman high stand of the Dead Sea lasted a long time, four centuries or so, from about 200  bc to about 200  ad. The ensuing low stand lasted more than a century; it was succeeded by a sharp increase in precipitation that continued for about 200 years.36

Izdebski and others refined the timing of the second high stand to a period spanning the sixth and early seventh centuries.37 This period coincides with a significant climatic cooling event in the northern hemisphere, termed the ‘Late Antique Little Ice Age from 536 to around 660 ad’, which is thought to have been triggered by a series of major volcanic eruptions.38 The study area lies in the Dead Sea catchment area, and the general palaeoclimatic trends reflected in the changes in lake levels observed in the Dead Sea can probably also be applied to the study area, but with the reservation that the impact of regional microclimatic differences on the palaeoclimatic history of the study area remains to be determined. Research on speleothems from caves in northern Jordan produced comparable palaeoclimatic data to that obtained from caves west of the Jordan valley and confirmed that Mediterraneansourced rainfall and similar mean annual temperatures to today existed throughout the Holocene.39 The study area’s position on the climatic gradient suggests that local microclimatic differences may be significant. Just how significant is not currently known, but the record of climate proxies in calcium carbonate sediment lining one of the north-west aqueducts to the city at site JWP128 provides confirmation of a prevailing bi-seasonal climate with variations in spring flows in the first–second cen35 

Rambeau and Black 2011. McCormick and others 2012, 218. 37  Izdebski and others 2016. 38  Büntgen and others 2016. 39  Robinson and others 2009. 36 

37 turies period.40 The interpretation of ‘a low-flow period in response to a drought’ associated with laminae 25 (‘L25’) in the calcium carbonate proxy record at site JWP128 may possibly relate to the sharp reduction in rainfall noted by Rambeau and Black around ad 100.41 Aside from temperature considerations, an overall decrease in rainfall has commonly been regarded as having the most significant impact on agriculture. Lucke, however, argued that flooding from an ‘exceptionally high number of heavy rainfalls’ in the Late Byzantine to Early Islamic period could have had an equally dramatic effect (see discussion in Chapter 10).42 The reliability and variability of rainfall also impact the level and scope of human activity, and Shehadeh emphasized the link between successful dry farming and early rainfall.43

Geo­logy The geo­logical strati­g raphy of the study area was first briefly described by Blake, Burdon, and Quennell and more comprehensively in Bender’s Geo­logy of Jordan and the regional study of sedimentary basins by Nairn and Alsharhan.44 The 1995 geo­logy plan by Abdelhamid remains the most detailed published plan available for the area.45 Pre-Quaternary Geo­logy The area forms part of a tilted and dissected limestone plateau formed from units of the Upper Cretaceous Ajlun Group (100.5–93.9 Ma), which comprise bedded limestone, marl, and marly limestone.46 These marine sediments were laid down on a shallow platform during the marine transgression that followed the deposition of the Lower Cretaceous Kurnub Formation sandstones and were subsequently uplifted into the Ajlun Dome.47 40  Passchier and others 2021. For radio­carbon dating results for site JWP128, see Table D1, Appendix D. 41  Passchier and others 2021, 11. 42  Lucke 2011, 593. For a broader discussion on the impact of extreme weather events on land use and erosion, see Lucke 2017. 43  Shehadeh 1985, 30. 44  See Blake 1939; Burdon 1959; Quennell 1951; Bender 1974; Nairn and Alsharhan 1997, 358–60. 45  Abdelhamid 1995. Geo­logical plans published by Hammouri and El-Naqa (2008) and Abu-Jaber, al-Saad, and Smadi (2009) rely on data published by Abdelhamid. 46  Abdelhamid 1995. 47  Quennell 1951, 106.

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Quaternary Geo­logy The Quaternar y period comprises the Holocene and Pleistocene epochs and encompasses the last 2.588  Ma of the earth’s history. 50 Surficial Holocene to recent geo­logical units (alluvium, soil, and minor calcrete) were mapped in the study area by Abdelhamid; however, the study recorded additional Quaternary depositional events and weathering processes tentatively dated to the Pleistocene epoch that are described below.

Calcrete

Figure 3.8. Simplified bedrock geo­logy map. Drawing N. Ellis.

The incision of the Jarash and Majarr–Tannur valleys into Cretaceous basement rocks sequentially exposes the entire sequence from the Balqa Group at the top to the Lower Cretaceous Kurnub Formation at the base over the length of these valleys. A plan showing the bedrock geo­logy of the study area is presented in Figure 3.8.48 The formational litho­logies are listed and briefly described in Table 3.1.49 Aquifers are found in all of the Cretaceous formations and are discussed in the Subsurface Hydrogeology section, beginning on p. 60. These aquifers sustained the springs described that were a major water source in the study period. 48 

Figure 3.8 is based on the geo­logical mapping of Abdelhamid (1995) and the author’s observations. 49  For a recent regional appraisal of the strati­graphic and struc­ tural context focusing on the pre-Quaternary geo­logy, see Holdridge 2020.

Within the study area, calcrete occurs as a secondary (authi­genic) deposit precipitated from carbonatesaturated solutions that have formed on Cretaceous and some Quaternary formations.51 It is particularly well developed as a hard, massive duricrust on marls and limestones of the Upper Cretaceous Na’ur and Fuheis Formations and on Quaternary Jarash Conglomerate. The exposed karstic surface of the duricust is typically smooth and marked by depressions and solution features, which produces rock pavement landforms with a distinctive dimpled appearance when viewed from above. In gently dipping Upper Cretaceous domains, the calcretized surface has a characteristic stepped appearance that reflects compositional differences in the strati­ graphy (Fig.  3.9a). In Jarash Conglomerate domains, the calcrete forms a sheet-like duricrust that follows the natural surface slope and is a remnant palaeosurface (Fig. 3.9b). In both Cretaceous and Conglomerate 50 

Gibbard and Head 2009. For descriptions of calcrete typo­logy and discussion on calcrete formation, see Nash and McLaren 2007, 10–46; Itkin and others 2012. 51  

Natural Environmental Contexts

39 domains, the smooth duricrust surface creates ideal runoff conditions but supports only thin, fragile soils that are susceptible to erosion.

Jarash Conglomerate

Figure 3.9. Aerial views of karst calcrete landscapes in the Jarash valley. (a) Calcretized Upper Cretaceous, Ar Rashayidah village, adapted from APAAME_20130428_ DDB-0732, photo­grapher D. Boyer, courtesy of APAAME; (b) Calcretized Jarash Conglomerate duricrust at sites JWP122/123, Khirbet esh Shawahid. Adapted from APAAME_20101021_DDB-0270, photo­grapher D. Boyer, courtesy of APAAME.

Table 3.1. Strati­graphic classifications within the Jarash valley watershed. Epoch

Group

Formation Symbol Rock Type (Simplified)

Upper Cretaceous

Balqa

Amman

B2

Chert/limestone

Ghudran

B1

Chalk/marl/limestone.

Ajlun

Wadi Sir Shueib Hummar

Lower Cretaceous

Kurnub

A7

Hard limestone/chert layers

A5/6

Limestone/marl

A4

Hard limestone

Fuheis

A3

Marl/limestone.

Na’ur

A1/2

Limestone/marl

 

K

Sandstone/shale layers

The study identified remnants of a fluviatile unit, informally named the Jarash Conglomerate, over a c.  5  km 2 portion of the central Jarash valley that includes the entire city area (see Figure 3.8).52 The unit was also identified in the Majarr–Tannur valley, but its extent there has yet to be mapped. The unit lies unconformably on Cretaceous Na’ur limestone and Kurnub sandstone.53 In the Jarash valley, the unit’s basal contact with Na’ur limestone is preserved at Qairawan Cave in the city (Fig. 3.10) and has an observed true thickness of up to 8 m near the city’s North Gate. The most extensive exposure is at Bab Amman to the east of the Hippodrome, where the unit caps a terrace on a ridge summit (hereafter Bab Amman mesa) c. 700 m long and up to 120 m wide (Fig. 3.11). The conglomerate contains rounded rock fragments (clasts) that occasionally exceed 1.0 m in length. The clasts are dominantly limestone, with minor flint, chert, and basalt, and the sedimentary structures and fabric point to fluviatile deposition in a high energy environment. The unit’s uppermost surface has been calcretized to form a hard duricrust 1–3  m thick.54 The conglomeratic fabric is often difficult to discern in the duricrust, particularly in conglomeratic zones dominated by Cretaceous limestone clasts but is more readily identifiable in exposures below the crust. The broad distribution of Jarash Conglomerate in the city area had not been recognized prior to the present study. Holdridge noted the occurrence of the fluviatile conglomerate at low elevation in the 52   See Boyer 2018a; 2018b; 2018c; 2018d. This unit was described as the ‘Abu Suwan Conglomerate’ in Amman, MS Jarash Hinterland Survey 2010 Preliminary Report. 53   For an alternative view on the nature and distribution of the Jarash Conglomerate (‘fluviatile conglomerate’), see Holdridge 2020, 59–60. 54  Calcrete is also known as caliche. It can form as a result of pedo­logical processes or from groundwater, but it is not clear which processes were active locally.

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Figure 3.10. The unconformable contact between Pleistocene Jarash Conglomerate and the underlying Upper Cretaceous Na’ur Formation at Qairawan Cave spring on the eastern bank of Wadi Jarash in the city.

Figure 3.11. Oblique aerial view of the Bab Amman mesa, looking north-east. Adapted from APAAME_20101021_DDB-0349. Photo­grapher D. Boyer, courtesy of APAAME.

Natural Environmental Contexts

41 Figure 3.12. Exposures of Jarash Conglomerate in the vicinity of Gerasa. The circles are the locations of exposures of Jarash Conglomerate shown in photo­graphs in Figure 3.13. Base plan from Stott, Raja, and Lichtenberger 2019.

Bab Amman area and suggested that it formed part of an older wadi terrace.55 The present study showed that the conglomerate is not limited to lower elevations: it has been observed up to elevations of at least 600 m in the city area and even higher elevations in the city’s hinterland. The difficulty in distinguishing the duricrust over Jarash Conglomerate from Upper Cretaceous Na’ur limestone probably accounts for the bedrock of the city area being shown as Na’ur limestone on the 55 

Holdridge 2020, 59.

available published geo­ logical maps. 56 These maps correctly identify the Cretaceous basement geo­logy, but they do not correctly reflect the uppermost g eo ­ logical bedrock unit in the strati­ g raphy. Examples of outcrops in the city area exhibiting Jarash Conglomerate fabric are located in Figure 3.12, and photo­ graphs of these sites are presented in Fig ures 3.13a–3.13h. The dating of the Jarash Conglomerate is conjectural but based on strati­g raphic and compositional similarity ; the working hypothesis is that it is contemporaneous with the Dawqara Conglomerate in the Zarqa valley, c.  20  km to the south-east of Jarash. The preliminary conclusion from research in the 1990s was that the Dawqara Conglomerate and the lithics that it contained were dated to the Lower–Middle Acheulian period, around 0.9–1.0  Ma  bp. 57 Recent research, however, has shown that the formation has a terminus ante quem of 1.98 ± 0.20 Ma — close to the beginning of the Pleistocene epoch — and contains hominin lithics, some of which show evidence of fluvial 56  See Abdelhamid 1995; Hammouri and El-Naqa 2008, fig. 2; Holdridge 2020, fig. 2.1. 57  Parenti and others 1997, 19–20.

42

Figure 3.13. Photo­graphs of sites showing exposures of Jarash Conglomerate in the vicinity of Gerasa identified in Figure 3.12. (a) Cascade spring, North-West Quarter (scale 20 cm); (b) Below ashlar wall, north of Odeon; (c) Western wall of rock-cut reservoir, North-West Quarter; (d) Scarp, west of Genesius Church (scale 20 cm); (e) Below column, South Decumanus (scale 20 cm); (f ) Cistern in a cave beside Mortuary Church (scale 1 m); (g) Qairawan Cave spring (scale 2 m); (h) Surface north of Hadrian’s Arch (scale 20 cm).

Chapter 3

Natural Environmental Contexts

43

Figure 3.14. Examples of possible flint lithic artefacts embedded in the Jarash Conglomerate at Bab Amman. (a)–(c) Examples embedded in calcretized Jarash Conglomerate; (d) Flint lithics (arrowed) within the Jarash Conglomerate exposed in a cave.

transport. 58 Possible flint lithic artefacts have been observed in situ within the uppermost levels of the Jarash Conglomerate at several locations in the Bab Amman but have not been evaluated in detail (Figs 3.14a–3.14d). The Jarash Conglomerate has impacted human communities in the area in a variety of practical ways for an extended period. The unit’s porous nature made it an ideal aquifer host, and, although small, these aquifers supplied many important strong-flowing low-elevation springs 58  Scardia and others 2019, 12. For an overview of the evidence of hominin presence in the Levant in the Lower and Middle Palaeolithic, see Rollefson 2019b.

in the central Jarash valley until relatively recently. 59 The concentration of flint cobbles in the Bab Amman and Tannur spring localities may have encouraged the Neolithic settlements established at these locations, and the many natural caves in the city and Bab Amman localities were modified for use as tombs in extensive necropoleis established in the Hellenistic–Early Roman period. The unit’s massive duricrust, known locally as nari, was quarried extensively in Antiquity for use in arches and domes because of its significantly lower relative density 59 

The aquifers and springs are discussed in the Subsurface Hydro­geology section, pp. 60ff.

Chapter 3

44

Figure 3.15. Soil characterization map. Satellite base map data, Google © 2021 CNES/Airbus.

(1.96) compared to crystalline limestone (2.5).60 Nari was used, for example, in the construction of the South Bridge and the vaults beneath the Artemis Temple cella. The inherent strength of the duricrust allowed for the natural roofing of tombs and cisterns and often obviated the need for slab or arch-supported roofs.61

Spring Tufa Spring tufa deposits are found at many of the spring cascade (waterfall) sites in the study area, especially the relict karst springs. Their significance lies not in their strati­ graphic thickness — most are thin incrustations — but 60 

Blake 1939, 127–28. A similar use of natural limestone roofing of cisterns built in the underlying softer chalk has been noted in the settlement of Oboda in the Negev; see Oleson 2010, 464, 477. See also Kloner (2002) regarding the natural roofing of cisterns at Maresha in the Judaean Highlands. 61 

in the information that they can potentially provide on palaeoclimate and hydro­logy. The most extensive known tufa deposit is the relict tufa cascade exposed over a 200 m long section of the east bank of Wadi Jarash south of the South Bridge, although it probably extended over a greater distance along the wadi bank in Antiquity.62 It lies at the western edge of a tufa terrace that covered around 20 ha at the southern end of the eastern lower terrace. The tufa terrace would have extended westwards from the presumed water source at the foot of the escarpment (scarp) that now roughly follows the 575 m contour. The southern half of the late nineteenthcentury Circassian village was built on this terrace and over the relict source, and the terrace is now overbuilt by the modern town. The tufa is at least 3 m thick at the foot of the cascade, and this thickness implies spring flow over an extended period. JWP radio­carbon dating 62 

The true strati­graphic thickness of the tufa in the cascade is probably only a few metres.

Natural Environmental Contexts

45

produced tentative dates that ranged from Iron Age at the top to Upper Palaeolithic at the base.63 The Upper Palaeolithic date suggests that the tufa cascade may be roughly contemporaneous with the extensive ‘Bet Shean travertine’ on the west side of the Jordan valley dated to 41,000–22,000 bp; however, the tufa sample (a soda straw) from Jarash may have been affected by calcite recrystallization, and further sampling and analysis are required for verification.64 Despite the tufa cascade’s prominence as a landform, the only published reference is by Vita-Finzi, who considered it analogous to preNeolithic tufas at Ain Fasayil and Ain Auja.65 While the study found most examples of spring tufa at the sites of spring cascades, traces of tufa can also be found at several fountain outlets along the Cardo.

Regolith The term regolith refers to unconsolidated material lying on solid bedrock. It includes weathered bedrock and many kinds of residual and transported material, but the study focused on the soil and colluvium components. Soils A detailed discussion of soils and their physical properties is outside the scope of this study, but the soil resources summary below provides contextual background to the discussion of settlement patterns and water demand. No detailed study of soils covering the whole project area has been published to date; however, soil characterization data collected by the National Soil Map and Land Use Project (NSMLUP) and published as 1:50,000 scale plans provide a useful basis for discussion.66 This project characterized the local soils as xerochreptic Inceptisols under the USDA (1990) classification, with differences 63   The upper sample is B-425330, and the lower sample is B-425329: see Table D1, Appendix D. 64  For the dating of the Bet Shean travertine, see Kronfeld and others 1988. 65  Vita-Finzi 1964, 22. 66  See Ministry of Agriculture 1989–1995. For recent pilot studies that include soils within the city, sediment profiles in the Jarash valley, and commentary on important research questions that need to be answered, see Holdridge and others 2017; Kristiansen, Holdridge, and Simpson 2017; Cresswell and others 2018; Lichtenberger and others 2019; Holdridge others 2020; 2021. For an overview of soils in Jordan, see Lucke, Ziadat, and Taimeh 2013. For earlier brief commentary on soils in the city area, see Lucke 2007, 52–53. For a more detailed study of Jordanian soils, see Lucke 2017, esp. 19–69.

Figure 3.16. Profile through the base of a terrace east of the Hippo­ drome at Bab Amman showing an anthrosol and cultural deposits lying on natural Red Mediterranean Soil (vertical pole 2 m).

defined by elevation, topo­graphy, rainfall, parent material, moisture regime, presence of stones and bedrock, particle size, and soil depth: current land use was also noted. A modified presentation of generalized soil characterization boundaries within the study area from the LSMLUP data is shown in Figure 3.15.67 Inceptisols are known as Cambisols in the World Reference Base of Soil Resources and as Red Mediter­ ranean Soils (RMS) — or terra rossa if developed over limestone — in older soil classifications.68 Similar distinctive soils cover Cretaceous bedrock throughout the Ajlun Dome. Possible Calcisols were also observed on some limestone slopes during the field survey, but their distribution is unknown. 67  The Jerash map dataset was based on analysis of Landsat satellite data (TM bands 4, 5, 3 collected 5 April 1992, and SPOT satellite Panchromatic data collected 3 May 1992). 68  See Lucke, Ziadat, and Taimeh 2013; Ziadat and others 2015.

Chapter 3

46

they were formed and whether they are still forming, but recent research argues convincingly that these soils are mainly aerosols and were likely developed in the pre-Holocene period.70 Terra rossa soil profiles in the city area are usually only observed in archaeo­logical excavations, as they tend to be covered by later colluvium, cultural deposits, and anthrosols: it was also common for building foundations in the city to be taken down to bedrock. An example of a profile showing an anthrosol and cultural deposits overlying natural RSM soil is shown in Figure 3.16. Na t ur a l R M S p r o f i l e s described from sites below or adjacent to the ancient city wall in the city’s North-West Quarter (trench ‘Q’) refer to a red A horizon in sharp contact with an underlying B horizon, which is underlain in turn by a stony B/C horizon. 71 The existence of the yellow B horizon may be unusual in the local context. Elsewhere in the study area, the author has noted that natural RSM soils preserved in depressions and solution features in the bedrock surface typically comprise a red A horizon grading into an underlying B/C horizon Figure 3.17. Examples of in situ Red Mediterranean Soil profiles developed on limestone. that becomes increasingly stony (a) On a slope west of the walled city at site JWP127, adjacent to aqueduct JW01; (b) Soil profile in the eastern part of the modern city (vertical pole 1 m). with depth (Figs 3.17a–3.17b). The relative thinness and distinctive red colouration of the A horizon in natural soils Field observations show that soil distribution and contrast with deeper soil profiles observed elsewhere thickness is determined by topo­g raphic relief, with on natural and constructed terraces, where a relatively thicker accumulations in depressions on plateau surfaces, homogenous dark brown or red A/B horizon sits directly on terraces, and on valley floors. There is no general agreement as to whether RMS soils are residual (developed from the dissolution of the underlying bedrock or 70  See Lucke and others 2014; Vingiani and others 2018. by metasomatic replacement) or are aerosols blown in 71  Cresswell and others 2018, 3. A similar soil profile is shown from elsewhere.69 There is also disagreement about when 69 

For a discussion on the various origins, see Singer 2007, esp. 102–06; Lucke and others 2014; Lucke 2017.

in Kristiansen, Holdridge, and Simpson 2017, fig.  2a. Optically Stimulated Luminescence (OSL) dating results from the city area suggest that the soil surface was covered in the Hellenistic period (450 bc–250 bc); see Cresswell and others 2018, 11.

Natural Environmental Contexts

47

on, and in sharp contact with, bedrock (R horizon) (Figs 3.18a–3.18b). These terrace soils are not considered to be natural in situ soils; instead, they are likely to be accumulations of eroded soil deposited by creep and runoff and have been mixed by anthroturbation and faunalturbation. An example of such an RMS profile that accumulated in an ancient quarry that is presumably of Hellenistic or later date is presented in Figure 3.18c. In some cases, soils may have been brought in by farmers from elsewhere, such as the anthrosols identified in trenches in the city’s NorthWest Quarter.72 The NSMLUP survey results identify soils in diverse geomorpho­logical and climatic conditions. Soils with a wet Xeric moisture regime are limited to the Jarash watershed. Soil texture varies; most soils have a stone component, which is typically concentrated near the bedrock interface, and soils on the plateau immediately west of the city have an important clay component. There are apparent differences between the soils of the Jarash and Majarr–Tannur watersheds, with thin, skeletal, rangeland soils more suited to pastoral use being much more widespread on the rocky ridgetops and upper slopes within the Majarr–Tannur watershed. When conditions are suitable, rainfed (dryland) farming is possible in soilcovered areas over the entire study area, but production is affected by soil texture; deeper soils permit better root formation, and clayey soils are better able to retain moisture.73 Verheye and de la Rosa noted, ‘Amongst the cultivated perennials there are few trees like olives, figs, almonds and pistachios, as well as grapes which are able to survive under Mediterranean 72   See Holdridge and others 2017, fig.  4; Holdridge and others 2020. 73   Verheye and de la Rosa 2009. For a discussion on the definition of dryland agriculture, see Stewart, Koohafka, and Ramamoorthy 2006. For commentary on the impact of the physical properties of soil on evapotranspiration, see Duffková 2013.

Figure 3.18. Examples of homogeneous RMS soils (not in situ) sitting directly on bedrock. (a) Thick soil profile developed on mid-level terrace overlying Upper Cretaceous limestone in upper Wadi Suf; (b) Thick soil profile developed on a terrace in the southern Wadi Jarash lying on Jarash Conglomerate; (c) Soil infilling ancient quarry on the west bank of Wadi ed Deir valley (pole 2 m).

Chapter 3

48 rain fed conditions without damage’. Crop selection, therefore, often depends on water availability, with supplementary irrigation increasing the cropping options. The NSMLUP land use data demonstrate the close association of dryland farming intensity with thicker soil accumulations and a wet xeric moisture regime, which is limited to the Jarash watershed and, in particular, to the area west of a north–south line along Wadi Asfur, Wadi ed Deir, and Wadi Jarash. Given the evidence of similar or wetter local climatic conditions, it is likely that the same would also have been the case for much of the Hellenistic–Byzantine period, and this theme is revisited in the context of the settlement history in Chapter 4 and irrigation in Chapter 8. The fragile soils in upland areas are prone to erosion, particularly on steep slopes in calcrete-karst areas. Extensive pavements of exposed bedrock are testament to severe past erosion on the west and south-facing slopes, such as are found on the eastern sides of the Jarash and Majarr–Tannur valleys and the reworked soils were carried by runoff into nearby wadis and accumulated on the valley floors. Just when this erosion occurred, the nature of the original natural vegetation, and to what extent erosion and perhaps deforestation was exacerbated by agropastoral activities are open questions. Soils in these eroded areas are preserved in the many small pockets in the karst surface and in larger terrace-like areas that are often the benchtops of stabilized landslides. Some of the reworked soil material would have initially found its way into the main wadi drainages, but this source of wadi sediment was progressively eliminated by the establishment of slope terraces and cross-wadi walls in the tributary wadis. These tributary wadis have long since ceased to contribute sediment to the main wadis, and ephemeral flows are limited to small superficial streams. Analysis of early twentieth-century aerial photo­graphs reveals consistent evidence of old cross-wadi walls in tributary wadis being in a well-maintained and stable condition, which suggests that reworked soil movement had been effectively managed over a long period, although their construction date is unknown. The condition of the adjacent slope terraces is less easy to determine as they are difficult to distinguish from natural terraces, but there is no obvious evidence of negligent management. The tradition of maintaining terrace and cross-wadi walls continues to this day. Terraces are poorly preserved in Wadi Jarash south of the city, particularly on the east bank, which is particularly prone to landslides, but APs show that ancient terraces were still preserved on the west bank of Wadi Jarash in the Shallal locality in the mid-twentieth century.

Relict ancient rectangular field walls on the upper slopes and hilltops on the east side of the Majarr–Tannur valley were considered by Sapin to date to the Classical period.74 Examples of these walls can be found throughout the Majarr–Tannur valley and are particularly visible on APs from the 1920s. Many of the walls run downslope and cannot have had a soil-retention or runoff control function. The majority of the enclosed and part-enclosed areas are devoid of soil except where it has accumulated in depressions and potholes or on natural terraces. Sapin considered that the lack of soil reflected erosion that took place after the walls were built; however, the lack of significant soil accumulation against the walls indicates that the walls were built on terrain already soil-depleted. Sapin also argued that the general absence of walled fields on the soil-depleted lower slopes was evidence that the erosion on the lower slopes occurred prior to the Classical period and attributed it to agricultural activities and deforestation in the Late Chalcolithic–EB1 period. However, the removal of soil in these areas may just as plausibly have occurred before prehistoric occupation and be due to non-anthropogenic causes. The slopes are surfaced with hard calcretized limestone. Soil retention is poor; such soils are easily erodible under natural conditions and it is not necessary to invoke anthropogenic causation. It is posited that the walls enclosed areas of patch and pothole farming used for the cultivation of crops such as olives or vines after the natural vegetation had been removed. The walls may have delineated land ownership and/or served to control grazing animals, a conclusion also reached by Lucke in his study of field walls in northern Syria.75 The cultivation potential of such apparently barren land is demonstrated in Figure 2.6, which shows a successful reafforestation project and modern olive orchards developed in an area of rocky slopes and ancient field walls in the Majarr valley. Soil-filled potholes observed on a flat ridgetop at site JWP186, 1 km west of Riyashi spring, are around 4 m in diameter and frequently show signs of human modification. Specimens of Quercus were growing in several potholes, and bedrock mortars and cupholes found on adjacent surfaces demonstrate that the condition of the prehistoric land surface was essentially the same as the modern-day surface. Examples of patch fields dated to the Chalcolithic period have been described from sites west of the Jordan River.76 74 

Sapin 1992, 171–73. Lucke 2017, 136. 76  Gibson and Lewis 2017. 75 

Natural Environmental Contexts

Colluvium

Colluvium in the City Many of the lower slopes and ruins in the city area were once covered by colluvium, although much of it on the western side was subsequently cleared away by archaeo­ logical excavations and clearances, and colluvium on the eastern side is obscured by the modern town.77 The colluvium was derived from material sourced from the upper slopes within the city area after the city walls were built. These walls formed an effective barrier to the introduction of colluvium into the city area from outside sources; however, colluvium also accumulated on the hillslopes beyond the walls, as is attested in the regolith profile exposed in the excavations of the South-West Gate (Fig. 3.19).78 77  For an early contemporary observation on colluvium in the Jarash area by sheet erosion, see Lowdermilk 1948, 10–11. 78  The western city wall was built on an east-facing slope with an extensive catchment to the west. The relative thinness of colluvium built up against the outside of the city wall contrasts with the thicker accumulation of colluvium on more gentle slopes within the walls

49

Figure 3.19. Regolith profile at the South-West Gate (looking west) showing the development of sheet-wash gravels at the base of the profile exposed outside the gateway.

The commonest visible form of colluvium on the western side of the city is sheet-wash gravel, which is preserved as poorly consolidated, ill-sorted gravel layers. These gravels are typically clast-supported and exhibit a wide range of clast sizes. Examples of sheet flow gravels in the city area are shown in Figures 3.20a–3.20b. While some colluvium accumulated after the abandonment of the city as an urban centre in the tenth century, there is archaeo­logical evidence that colluvial gravels were already accumulating against the west wall of the Odeum in the fourth century and over the North Decumanus by the fifth century.79 Additional evidence for gravel accumulation in the city area by the fourth century comes from the dating of charcoal in gravels in and demonstrates the importance of local environmental factors on colluvial sedimentation. 79  For the North Decumanus, see Ball and others 1986, 353–57. For the Odeum, see Bowsher 1986, 243–47.

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Figure 3.20. Examples of deposits of colluvial gravels from the western side of the city area. (a) View of the southern colonnade of the Artemis upper terrace during excavation. From Kraeling 1938, pl. XXVc. Public Domain; (b) Gravels deposited against the wall of the lower terrace of the Temple of Zeus.

the south-west corner of the Artemis upper terrace in the present project, and there is also a case for drawing an analogy between the Artemis upper terrace gravel sequence with the sequence on the west side of the Odeum on textural grounds (Figs 3.21a–3.21b). At both locations, there is evidence that the onset of climatic conditions around the fourth century that triggered the colluvial gravel deposition occurred abruptly. Further corroboration of the accumulation of gravels by the fourth or early fifth century comes from the Birketein Baths, 1.2 km north of the city, where charcoal in gravels deposited over the bathhouse hypocaust give similar dates to the sample from the Artemis upper terrace, despite the fact that in both locations the charcoal is in redeposited material (Fig. 3.21c). The timing of the influx of sheet-wash gravels into the city area and the wadis is revisited in the context of changes in the physical environment in the Byzantine period in Chapter 10. A detailed study of these gravels remains a desideratum. A recent study of regolith profiles in the NorthWest Quarter by the JNWQ team found evidence of colluvium horizons alternating with introduced anthrosols in ‘Area R’, which appear to be early examples of a tradition of introducing transported terra rossa for farming purposes that continues in the study area today.80 80 

Holdridge and others 2017. Transported anthrosols from

Of particular interest in this trench is an OSL date of 1010±200 bc (SUTL 2877) from colluvium deposited just above bedrock, which is considerably older than the OSL date of 250±190 bc (SUTL 2962) from a sample of the basal colluvium to the west of the Odeum.81 These dates suggest that colluvium was accumulating in the city area as early as the Iron Age II–Hellenistic period.

Colluvium in Wadis Today, the beds and banks of the main wadis are lined with thicknesses of colluvial and alluvial sediments, with narrow active channels in the main wadis. The dominant flow regime is intermittent, with perennial flow limited to trivial flows in southern Wadi Jarash. Wadi sediment transport under the present intermittent flow regime is minimal other than during rare episodic flood events. Wadi baseflow is provided by the surplus discharges from springs close to the wadi alignment. The Jarash valley would have carried a much stronger flow in Antiquity, although the quantum of this flow, the uses to which the water was put, and the extent the baseflow was reduced in the dry season by aqueduct offtakes remain open questions.

the Islamic period have also been recorded in the city’s South-West Quarter; see Rattenborg and Blanke 2017, 329. 81  Cresswell and others 2018.

Natural Environmental Contexts

51

Figure 3.21. Evidence of the deposition of gravels in the fourth century. (a) West side of the Odeum, showing layer dating from Bowsher 1986; (b) The south-west corner of the Artemis upper terrace, showing the location of radio­carbon samples; (c) A comparison of 14C AMS dates obtained from gravels on the Artemis upper terrace and at the Birketein Baths.

The flow regime in the wadi is determined by natural factors (climate, tectonics, and geomorpho­logy of the wadi and its catchment) but may also be influenced by anthropomorphic impacts on water availability and soil distribution. Following the early cessation of colluvium contributions to the main wadis from tributary wadis

noted above, colluvium entered the wadi stream directly from slope wash (soil creep) and mass-wasting colluviation events on the wadi banks triggered by rainfall and seismic events (collectively, wadi bank colluvium). The nature of these colluviation events is largely determined by wadi geomorpho­logy: slope wash can enter the wadi

52

Chapter 3

Figure 3.22. Slope map of the study area, highlighting areas of steep slopes within the main valleys. Slope data (five-degree classes) by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

stream at virtually any point along its length, but wadi bank colluvium from mass-wasting events such as earth slumps, debris flows, and landslides only occurs in areas with steep unstable slopes. These unstable slope conditions are particularly prevalent in southern Wadi Jarash and Wadi Tannur, where the steepest slopes in the study area are to be found, and to a lesser extent in Wadi Suf (Fig. 3.22). Mass-wasting events continue to be a problem in the southern Wadi Jarash and Wadi Tannur, as is discussed in the Seismic History section below. Notwithstanding the steepness and instability of these lower wadi slopes, there have been attempts since historical times to construct terraces on them because of the richness of the soil and the availability of water for irrigation. The efficiency of terrace management in these areas has a bearing on ongoing slope stability and on containing colluviation events such as soil creep, but some mass-wasting events were so rapid and on such as scale as to overwhelm even well-managed terraces. There are, therefore, limits in the way human intervention can mitigate mass-wasting colluviation events. The steep unstable lower slopes in the main wadis offer particular challenges to terrace farmers: they are not typical of terrace farming conditions elsewhere in the study area, and

failure of terraces on such extreme slopes cannot, on its own, be taken to imply a general failure of terraces across the hinterland. It is thought unlikely that the deep, stable soils in valley floor positions contribute much colluvium to the main wadis except in exceptional runoff conditions. The wadi bank colluvium mixes with fluviatile alluvium already in the wadi (itself essentially reworked colluvium from upstream) to form unstratified or poorly stratified sequences that reflect multiple successive degradational and aggradational (cut and fill) events. Sediment accumulation would not have been consistent throughout the main wadis due to the differences in gradient and wadi geomorpho­logy. The change from a degradational to an aggradational regime may have been gradual and may have included periods when the accumulating sediments were essentially flushed through the valley by flood events without leaving an archaeo­logical trace.82 A study of the Ficus Springs site in Wadi Jarash, 1 km south of the city, provides an example of the complex 82  An alternative explanation of the absence of sedimentation is that it reflects better management of water and soil resources; see for example Holdridge and others 2021.

Natural Environmental Contexts

53

Figure 3.23. Colluvium deposits at Ficus Springs. (a) View upstream showing the positions of the top of the historical debris flow that buried the wadi channel and the top of the slope wash; (b) View of slope wash and earth flows on the west bank of the wadi.

interplay of degradational and aggradational regimes. The locality was once the site of a narrow, eroded wadi channel confined by steep sandstone cliffs, but the channel has since been largely filled with colluvium. The site has many relict rock-cut water-management installations, but many more are obscured by subsequent colluviation events, especially on the west bank. Here, there is evidence of a debris flow event that filled the wadi channel and many of the water management installations to a depth of at least 7 m (Fig. 3.23a). The debris flow was largely exhumed by subsequent degradational events, and, finally, the debris flow remnants and the wadi channel were partially covered with slope wash and

earth flows. (Fig. 3.23b). The debris flow contains artefacts, including a stone hammer (Fig.  3.24a) and covers an inscription that has yet to be formally identified and dated (Fig. 3.24b). Recent pilot studies by the JNWQ team have looked at regolith profiles at several sites close to the wadi bed within the Jarash valley, and OSL dating yielded important absolute dates.83 These studies of wadi sediments in the so-called ‘Wadi Suf ’ ( Jarash valley in this volume) identified alternating horizons of colluvial and fluviatile sediments at three widely separated sites.84 OSL dates were obtained at the 83  For regolith profile studies in the North-West Quarter of the city, see Lucke 2007, 52–53; Holdridge and others 2017; 2020; Cresswell and others 2018. For regolith studies in the wadi, see Holdridge and others 2017; Kristiansen, Holdridge, and Simpson 2017; Cresswell and others 2018; Lichtenberger and others 2019; 2021. 84  ‘Profile 1’, ‘Profile 2’, and ‘Profile LW1’; see Lichtenberger and others 2019. These sites are all located in sections of the valley

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Figure 3.24. Debris flow deposits at Ficus Springs. (a) Section through debris flow and overlying slope wash in bulldozer cut on the west bank of Wadi Jarash (insert shows stone hammer in debris flow); (b) Close up of debris flow and slope wash over a weathered bedrock slab bearing an inscription (insert shows inscription).

base of the sedimentary sequence at each location and at several higher levels within each profile. The samples from the base of the sequences returned OSL dates of ad  640±240 (‘Wadi Suf Profile’) at upper Wadi Suf, 2740±1690 bc (‘Wadi Suf Profile 3’) just south of the city, and 510±310 bc (‘Wadi Suf Profile LW1’) in the lower wadi. 85 These results show that the long-term aggradation phase did not occur uniformly throughout the valley, which is to be expected, given the variabilwhere slopes are moderate to severe. 85  See Cresswell and others 2018, 11; Lichtenberger and others 2019, 10.

ity in the geomorpho­logy of the valley, and in particular, the variation in valley floor gradient, which allows for the possibility of aggradation to be occurring in one section of the valley while scouring is co-occurring at another. 86 The sequence above the basal horizon (510±310 bc OSL date) in Wadi Suf Profile LW1 was dated at 33600±5900 bc (sample SUTL 2966), which suggests a strati­g raphic inversion, a phenomenon that was also recognized in geomorpho­logical studies in Wadi Ziqlab.87 The authors of the OSL studies interpret 86  87 

See the valley floor gradient data in Table 3.4. Field and Banning 1998.

Natural Environmental Contexts the results largely through the prism of human influence, positing that the deposition of the wadi sediments reflects ‘land degradation with declining maintenance of agricultural installations’.88 The upper Wadi Suf site results are particularly important. This site lies in a very narrow section of the wadi downstream of many very strong springs and in a channel with a gradient of 4.5 per cent. This should have ensured that it was one of the last places in the valley to allow wadi sediments to accumulate, but the OSL results show that sediments were accumulating around the seventh century ad. This change represents a substantial reduction in available water in the wadi, which must surely have been a direct result of climatic change. The errors in the OSL dating do not allow a precise estimation of when this climatic change occurred, but it occurs around the time of the onset of the long dry phase that followed the Late Byzantine wet phase of the sixth–seventh centuries.89 The colluvial sedimentation record in the wadis provides proxy evidence of past climate, the landscape, and human activities in the vicinity of the wadi but requires careful interpretation. There is no denying the potential influence of human activities on the water flow (and hence on fluvial sedimentation) in the wadi through control of water sources in the watershed, and the influences of agricultural practices such as terracing on overland water flow and soil creep on the potential supply of colluvium. However, the evidence of landslides and debris flows on steep slopes adjacent to the wadi bed points to significant periodic colluvial sedimentation resulting from sudden natural events probably unrelated to human activities.90

Vegetation Vegetation type distribution in northern Jordan is closely related to elevation and rainfall, and this gives rise to discrete vegetation zones in the study area.91 There are no comprehensive, published vegetation studies relevant to the study area, but there are several that include descriptions of vegetation in the northern highlands. Perhaps 88 

Lichtenberger and others 2021, 404. See Izdebski and others 2016. 90  Studies in Wadi Ziqlag on the eastern side of the Jordan valley, which has a similar geomorpho­logical environment to the study area, found that annual slope wash made only a small contribution to accumulation of sediments in the wadi; see Field and Banning 1998. 91  For a description of the bioclimatic zones, see Palmer 2013. 89 

55 the most detailed study to date is that by Atkinson and Beaumont, which, despite being fifty years old, remains relevant as it recorded remnant stands of tree species on a plan.92 A recent vegetation map of Jordan identifies four vegetation types that apply to the study area: (i) ‘Evergreen Oak Forest’ is found in the north-western part of the study area above an elevation of between 800 and 1000  m, where the annual rainfall is >375  mm; (ii) ‘Mediterranean non-forest Batha type’ covers c. 68 km2 in the Jarash valley and the western part of the Majarr– Tannur valley; (iii) ‘Batha-Steppe vegetation type’ is found on the east side of the Majarr–Tannur valley where average annual rainfall is currently less than c. 325 mm; ‘Deciduous Oak Forest’ is limited to the extreme southeastern corner of the study area (Fig.  3.25a). 93 The Mediterranean non-forest Batha and Batha-Steppe vegetation types are generally regarded as being degraded forest areas. The combined effects of climate change and human demands on natural resources means that only small remnants of the original arboreal vegetation are preserved, and it is difficult to understand the original extent and nature of the original cover. Observations by nineteenth-century visitors to the area help in identifying the nature of the natural vegetation cover before the onset of the significant changes wrought initially by the felling activities of Circassian settlers and subsequently by modern agriculture and urban expansion. These visitors described the forests around Ajlun and Suf and noted that the hills immediately surrounding the city were covered with sparse, scrubby maquis vegetation with occasional pollarded oaks.94 This commentary is confirmed by photo­g raphs of the city area taken in the 1850s to 1870s, which also show the area within the walls away from the wadi bed to be essentially treeless garrigue.95 Added to this, several place names that mention Butm (the pistachio tree) point to historical stands of pistachio woodland near Deir el Liyat.

92  Atkinson and Beaumont 1971. For later descriptions of tree species in the bioclimatic zones, see Al-Eisawi 1985; Cordova 2007, 62–94; Palmer 2013. 93  Palmer 2013, 87. 94  See, for example, Oliphant 1881, 166–73; Schumacher 1889, 292–98. 95  For early commentaries, see for example Buckingham 1821, 406–07; Lindsay 1838, 101; Tristram 1865, 559. For early photo­ graphs, see Rey 1861, pl. XX; Abujaber and Cobbing 2005, 86–101.

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Atkinson and Beaumont found that natural forests and woodlands in the northern highlands are restricted to areas with >400  mm of annual rainfall (Fig. 3.25b). They identified remnants of natural Aleppo pine forest (Pinus halepensis, with Arbutus andrachne) and mixed pine and evergreen oak forest (Quercus coccifera, with Pistacia palaestina) in the central plateau area between Deir el Liyat and Suf, and satellite imagery shows that fragments of these areas remain today. They also recorded more extensive areas of Q. coccifera forest bordering the northwestern and northern watersheds of the Jarash valley and regarded this forest to be a secondary or degraded forest replacing original pine and deciduous oak woodland. Small remnant stands of deciduous oak (Quercus ithaburensis) exist regionally at elevations below that for the evergreen oak forest, but seemingly not within the study area. Apart from this evidence, there is little factual data to inform a discussion on the vegetational history of the study area; however, the control on species distribution exerted by climate and elevation assists the process. Pine and evergreen deciduous forests are limited to the wetter, higher elevations, with optimal conditions for P. halepensis being rainfall of 350–700 mm and minimum temperatures of minus 2 to 10 degrees C.96 Research in Lebanon has shown that climatic impacts dominated in the pre-Holocene period. Recent pollen studies from Yammouneh on the eastern slope of Mt Lebanon have highlighted strong arboreal growth in the wetter interglacial periods, with steppetype vegetation advancing in the drier glacial periods. A sharp increase in arboreal vegetation occurred at the end of the Pleistocene (13–9 ka bc) with the onset of moist, warm Mediterranean climatic conditions.97 Figure 3.25. Natural vegetation maps. (a) Distribution of vegetation types based on data from Palmer 2013; (b) Arboreal species distribution based on data from Atkinson and Beaumont (1971, 309, fig. 2) in the context of modern isohyets. Five-metre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

96  97 

Chambel and others 2013. Gasse and others 2011; 2015.

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57

that reflects Aleppo pine afforestation. The authors note that, taken together with other pollen records in the southern Levant, the period after c. ad 450–950 is marked by the advance of garrigue species and of the replacement of original deciduous oak woodland (Q. ithaburensis) by evergreen oak woodland (Quercus coccifera).99 Today, dry-farmed olive cultivation extends over the whole of the Jarash valley catchment up to the elevation of the remnant Q. coccifera forest and over much of the garrigue-covered mid-slope areas in the Majarr–Tannur valley up to the level of the pine afforested areas. Allowing for the probability that this reflects a similar situation in Antiquity, it is easy to imagine that the expansion Figure 3.26. Map showing the revised position of the eastern boundary of the Jarash Basin of olive cultivation and agro-pastoalong prominent watersheds in the context of the original basin boundary defined by ral activities in the Hellenistic–Early Kennedy (2004a) and Gerasa territory boundary markers identified by Seigne (1997c). Byzantine period led to the expanAdapted from Kennedy 2004a, 205, fig. 8. Reproduced with permission. sion of garrigue vegetation at the expense of arboreal vegetation, especially in the Majarr– The Holocene pollen record from Lake Kinneret proTannur valley, but the composition and historical distrivides some insight into likely past vegetation conditions 98 bution of this displaced arboreal vegetation is not curin the study area. This record is dominated by pollen rently known. It is assumed that the boundary between from olives, evergreen and deciduous oak, and to a lesser extent, pine. The results show an expansion of steppe the arboreal and steppe vegetation would have oscillated in line with changes in rainfall and ambient temperature. vegetation in the Neolithic period that coincides with Both P. halepensis and Q. coccifera are resilient species increasing cultivation of olives and possibly related forthat, with certain topo­g raphic and rainfall limitations, est clearances, but population levels were seemingly low can grow over the entire Mediterranean climatic range, and climatic influences are also likely to have contributed. The greater concentration of olive growing in the and either or both may have formed the arboreal vegetation before the expansion of the garrigue.100 Chalcolithic–Early Bronze Age period (5000–3000 bc) has no obvious impact on native trees and shrubs in the pollen record. The significant drop in olive cultivation in Hydro­logical Setting the period between 3000 bc and the explosion in olive production in the Hellenistic–Early Byzantine period The local hydro­logical setting was assessed to contextu(c. 350 bc–ad 450) is marked by a concomitant increase alize the study of water sources and overall water manin deciduous oak pollen and to a lesser extent evergreen agement. The study area falls within the boundaries of oak pollen, but this situation is markedly reversed with the ‘Jerash Basin’ as defined by Kennedy, which is a subthe increase in olive cultivation in the Hellenistic–Early basin within the Amman–Zarqa hydro­logical basin.101 Byzantine period. The total oak pollen count recovers rapidly thereafter, but evergreen oak grows at the expense of deciduous oak. The pine pollen count remains roughly 99  Schiebel and Litt 2018, 588. constant throughout, other than a rapid modern increase 100  For research on Q. coccifera, see Al-Qaddi and others 2017. 98 

Schiebel and Litt 2018.

101 

Kennedy 2004a. The Amman–Zarqa hydro­logical basin is defined in Jordan. Ministry of Water and Irrigation 2000.

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Colour Plate 2. Map of drainage catchments and current dendritic drainage lines in the study area. Five-metre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

Kennedy described the Jerash Basin as a natural basin; however, while the watershed to the north and south-west is well defined, the eastern limit of the Jerash Basin is less obvious, and several interpretations are possible. Arguably, the prominent watershed lying immediately east of the Wadi Tannur– Wadi umm Qantarah drainage forms a more natural eastern boundary to the Jerash Basin and also coincides with a section of the Gerasa territorial boundary interpreted by Seigne from inscribed stone markers (Fig. 3.26).102 This eastern watershed also marks the limit of well-settled land watered by 102 

Seigne 1997c; 2019b.

Table 3.2. Catchment area statistics. Drainage Basin

Area (km2)

Jarash valley

54.7

Majarr–Tannur valley

43.5

Wadi al Abbarah

5.2

Wadi el Mabara

2.2

Wadi Abu Kalkha

3.0

Total

108.6

Natural Environmental Contexts

59

Table 3.3. Valley floor gradient statistics. Wadi

Start

SUF

Headwaters

End

Designation

Elev. (m) Elev. diff (m) Dist. (m) Gradient

Headwaters

1160

Headwaters

Suf Spring

Wadi Suf — Upper

875

285

3650

7.8%

Suf spring

Wadi Asfur Junction

Wadi Suf — Lower

630

245

5430

4.5%

ED DEIR

Wadi Asfur Junction

North Watergate

Wadi ed Deir

568

62

2450

2.5%

JARASH

North Watergate

South Watergate

Wadi Jarash — City

538

30

900

3.3%

South Watergate

Shallal

Wadi Jarash — North

475

63

2150

2.9%

Shallal

Tannur Junction

Wadi Jarash — Central

265

210

4210

5.0%

Tannur Junction

Zarqa

Wadi Jarash — South

235

30

1380

2.2%

Subtotal

925

20,170

4.6%

MAJARR– TANNUR

WADI UMM QANTARAH

Headwaters

Headwaters

990

Headwaters

Road Junction

Majarr Upper

743

247

2360

10.5%

Road Junction

Ain Al-Mayita

Majarr Lower

555

188

5670

3.3%

Ain Al-Mayita

Riyashi spring

Majarr–Riyashi

515

40

1645

2.4%

Riyashi spring

Tannur spring

Riyashi–Tannur

480

35

955

3.7%

Tannur spring

Wadi Jarash Junction Tannur

265

215

3895

5.5%

Subtotal

725

14,525

5.0%

385

8230

4.7%

Headwaters

 

 

900

Headwaters

Riyashi spring

Wadi Umm Qantarah

515

strong springs from the drier (Wadi Qunnayah) catchment to the east. Surface Hydro­logy Gerasa lies in the centre of the 20 km long Jarash valley that drains southwards to the Zarqa River. The study area encompasses the Jarash valley catchment and the adjacent 14.5  km long Majarr–Tannur valley catchment to the east. Three small adjoining catchments to the south-east were also included as they lie within the Gerasa horos markers described by Seigne. The disposition of the main drainage catchments and wadis is shown in Colour Plate 2, and catchment area statistics are provided in Table 3.2. The average gradient profiles of the valley floors within the Jarash and Majarr–Tannur valleys are c. 5.0 per cent (Table 3.3); however, the profiles in both valleys can be broken down into separate sections or stages based on knickpoints (sharp changes in slope) marked by waterfalls.103

The profile of the Jarash valley is shown in Figure 3.27. The drainages typically have steep sides and narrow floors, the exceptions being the broader floor of Wadi ed Deir immediately north of the city named el-hammar (hereafter the El-Hammar plain), and the floor of Wadi Majarr.104 These flatter-lying areas are up to 0.5 km wide, have deep soils, and would have been intensively farmed in Antiquity, as is the case today. The natural constriction at the southern end of the El-Hammar plain at the point where the wadi enters the city near the North Gate is a notable physio­graphic feature. This constriction reduces the width of the wadi to 60–80  m, and water flow has cut a shallow gorge into Jarash Conglomerate and Na’ur limestone bedrock up to 20 m deep through the ancient walled city, with knickpoints (waterfalls) at either end of the gorge. Flash-flood events in the Jarash valley catchment would tend to pond immediately upstream of this constriction, and potentially damaging high-velocity water flows would be funnelled through the gorge within the city.105 104 

103 

See n. 4 on p. 29 in this volume.

105 

For the naming of el-hammar, see Schumacher 1902, 163. Seigne (2004, 176 n. 24) recorded just such an event in the

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60

Figure 3.27. A longitudinal profile of the Jarash valley. Drawing N. Ellis.

The placement of bridges and other infrastructure in Wadi would have triggered the need for a flood control strategy in Jarash in the Roman period. This control strategy is attested by the strength of the bridge abutments, the placement of cutwaters on the upstream side of the South Bridge, the placement of a flow diversion wall on the downstream side of the South Bridge, and the existence of the southern watergate. Streamflow through the southern watergate was controlled via converging masonry walls 8 m apart.106 There must have been a gate structure controlling water entry to the city in the northern city wall, but there is a 32 m wide gap in the known alignment of the city wall at this point, and the design of the structure is, therefore, unknown.107

1990s. 106  The footprint of the southern watergate is shown on a 1:500 scale plan in the University Art Gallery Gerasa Collection (Negative 938.5999.5004.24). 107  The dimensions of the gap in the city wall are taken from a 1:500 scale plan in the YUAG archives (Yale, Gerasa Archive, Negative 1938.5999.5004.29).

Subsurface Hydrogeo­logy

Basic Principles of Water Flow in Karst Landscapes A proportion of the precipitation that falls within the study area ends up as surface runoff, and the deeply incised nature of the surface drainages is a testament to the past erosional power of this water flow. The balance of precipitation either evaporates or infiltrates the earth’s surface, where it may accumulate in aquifers. Bedrock in the study area typically comprises limestone that has undergone a chemical and mechanical weathering process known as karstification, which creates an irregular, undulating rock surface with occasional solution openings that aid rainwater infiltration and aquifer recharge.108 Some solution openings penetrate the substrate where they form conduits that can allow rapid water movement — also known as conduit flow — in an otherwise less permeable host rock.109 In hilly parts of the study area, karstification and the absence of continu108  For a detailed overview of karst hydrogeo­logy and geo­ morpho­logy, see Williams and Ford 2007. 109  For a description of conduit flow, see Palmer 1991.

Natural Environmental Contexts ous soil cover results in a distinctive landscape of ‘pavements’ of exposed bedrock.

Aquifer Characteristics Measures of hydraulic conductivity such as permeability and transmissivity may be determined from the analysis of pump tests conducted on water bores intersecting aquifer formations. In relative terms, published permeability estimates demonstrate, predictably, that the karst limestone aquifers of the Na’ur and Hummar Formations are more permeable than aquifers in the underlying more massive and homogeneous Kurnub Formation sandstone.110

Amman–Zarqa Groundwater Basin The Amman–Zarqa Basin is the highest-yielding groundwater basin in Jordan, and its hydrogeo­logical characteristics have therefore attracted considerable research attention and a growing corpus of publications. The first modern detailed assessments were conducted in the 1980s, and many useful hydrogeo­logical contributions have been made to the study area since then.111 The study of aquifers in the Jarash valley by Hammouri and El-Naqa was one of the few studies to deal directly with the present study area, but its usefulness is impaired by the small number of water wells and springs included in the study (ten and fourteen respectively).112 This number compares with four water wells and thirty-three springs in the present study area investigated by Al-Mahamid and 332 spring sites recorded during the present study.113 Three aquifer systems are recognized in the Amman– Zarqa Basin.114 The Upper System comprises aquifers contained in Upper Cretaceous units B2–A7 (refer to Table 3.1) and has the highest yield from water wells of the three systems regionally according to Al-Mahamid, but only underlies a small portion of the study area.115 The Middle System comprises carbonate aquifers hosted in the Hummar and Na’ur limestone formations. These 110 

See Hammouri and El-Naqa 2008, fig. 2. Al-Abed and Al-Sharif 2008; Al-Qaisi 2010; AlRawabdeh and others 2013. Al-Rawabdeh and others is a particularly important data source on climatic, geo­logical, and hydrogeo­logical aspects of the basin. 112  Hammouri and El-Naqa 2008. 113  Al-Mahamid 2005. 114  Al-Mahamid 2005, 81. 115  Al-Mahamid 2005, 105. 111   See

61 formations include marls and marly limestone units, and the main aquifers are limited to areas of karst limestone where solution openings provide both water pathways and storage capacity. The Lower System is wholly contained within the Lower Cretaceous Kurnub Formation sandstone, which is exposed in the southern Jarash valley and Wadi Tannur. This system is hydraulically confined but receives leakage from overlying aquifers. The rock is a well-bedded quartz sandstone unit, and aquifers are limited in capacity to relatively small, tight structural features (fractures, faults, and bedding planes). The highly permeable and locally cavernous Jarash Conglomerate formation contains an additional aquifer system to those previously recognized. Al-Mahamid recognized small Pleistocene gravel aquifers elsewhere in the Amman–Zarqa Basin, but they have not been previously described in the study area.116 The Jarash Conglomerate aquifers are unconfined and are recharged from rainfall falling on the limited exposed area (c. 5 km2 in the Jarash valley). The unit is almost certainly hydraulically connected to the underlying and adjacent Na’ur Formation aquifers. Springs Strong springs were noted in the study area by many early nineteenth-century European visitors. Qairawan spring within the city was frequently mentioned, and Burckhardt was particularly impressed by the strong springs at Suf.117 Today, despite a significant reduction in water flows in recent decades as a result of the impact of excessive extraction from water bores, springs still play an important role in the local agricultural economy. A detailed analysis of the springs was included in the present study as part of a broader analysis of water sources supplying the ancient water management system. Spring locations were identified from published topo­g raphic plans, aerial photo­graphy, satellite imagery, and field surveys. The coverage was comprehensive, particularly concerning the stronger springs, but was not exhaustive. Each spring was classified according to its aquifer source and an estimate made of its flow strength.118 Additional characterization was the separation of the dataset into modern springs (for which there is evidence of activity since the nineteenth century) from relict springs (that, from the available evidence, had probably become inactive before 116 

Al-Mahamid 2005, 81. Burckhardt 1822, 249. 118  The geo­logical mapping is by Abdelhamid 1995. 117 

62

Chapter 3

Figure 3.28. Map showing the location of modern springs based on data from Table 3.4. Satellite base map data, Google © 2017 CNES/Astrium; © 2017 DigitalGlobe.

Figure 3.29. Map showing the location of relict springs identified, based on data from Table 3.4. Satellite base map data, Google © 2017 CNES/Astrium; © 2017 DigitalGlobe.

Natural Environmental Contexts

63

Table 3.4. Spring location statistics in the context of the watersheds. Catchment

Modern Springs

Relict Springs

Modern and Relict Springs

Name

Area (km2)

Number

% total

Density/ km2

Number

% total

Density/ km2

Number

% total

Density/ km2

Jarash

54.7

179

62.2

3.3

17

38.6

0.3

196

59.0

3.6

Majarr–Tannur

43.5

97

33.7

2.2

26

59.1

0.6

123

37.0

2.8

Wadi al Abbara

5.2

7

2.4

1.3

1

2.3

0.2

8

2.4

1.5

Wadi el Mabara

2.2

2

0.7

0.9

0

0.0

0.0

2

0.6

0.9

Wadi Abu Kalkha

3.0

3

1.0

1.0

0

0.0

0.0

3

0.9

1.0

108.6

288

100

2.7

44

100

0.4

332

100

3.1

Totals

the nineteenth century). The identification of relict springs was, to a degree, subjective, and the total number in the study area is almost certainly understated. A summary of the spring study has been published, and the methodo­logy and results are discussed in more detail below.119

Distribution The locations of modern and relict springs are shown in Figures 3.28 and 3.29, respectively. Spring location statistics in the context of the various watersheds are summarized in Table 3.4. The Jarash valley has almost twice the number of modern springs as the Majarr–Tannur valley, but this concentration is reversed when considering relict springs. The smaller number of relict springs in the Jarash valley is likely influenced by the difficulty in identifying relict springs in this area as a result of development and farming activities, and the true number of such springs in this valley is, therefore, likely to be understated.

Water Temperature No springs with unusually high temperatures were observed during the survey, and the only hot spring in the study area identified on government plans is an unnamed spring located 400  m west of El-Hammam spring on the southern bank of the Zarqa River. 120 Schumacher described El-Hammam as a hot spring,121 but three decades later, Glueck noted that ‘The waters of the strongly flowing spring are not warm, but have the name El-Hammam nevertheless’. 122 Schumacher 119 

Boyer 2018d, 65–67. Jordan. Air Photo­graphy Survey 1950, Sheet 27/88. 121  Schumacher 1902, 114. 122  Glueck 1939b, 220–21. 120 

reported that the temperature of the El-Hammam spring was 28°  C,123 which places it at the upper end of the lukewarm category according to the scale published by Vouk.124

Aquifer Source The aquifer source for each spring was identified from the bedrock geo­logy at the spring site, which was determined from either the published 1:50,000 scale geo­ logical maps or field observations.125

Typo­logy Springs form as the result of the interaction between hydro­logical and geo­logical conditions that brings water from an aquifer to the land surface. No two spring sites are identical; their geomorpho­logical features are determined by the climate, the size of the aquifer, the nature of bedrock water transmission, and litho­logical type. The dominant bedrock type in the study area is limestone, and karstic spring sites are common, particularly in Jarash Conglomerate terrains. Although a sedimentary formation, Jarash Conglomerate is largely composed of limestone clasts and exhibits similar hydraulic properties to karstic limestone. Karst springs are the result of conduit flow within limestone bedrock and typically produce strong seasonal discharges from multiple outlets that form a cascade or waterfall when associated with a scarp or cliff. These outlets frequently have a distinctive form and are readily identified, even at relict sites. Karstic springs may emerge 123 

Steuernagel 1925, A276. Vouk 1950, 36–42. 125  For the 1:50,000 scale geo­logical maps, see Abdelhamid 1995; Sawariah and Barjous 1993. 124 

Chapter 3

64 from any part of a limestone formation but are particularly associated with escarpments and formational contacts. While solution cavities are features of karstic springs, other limestone springs have geo­logical features in common with springs hosted in Kurnub sandstone that occur in the Jarash valley downstream of the city. Non-karstic springs may be related to perched water tables, litho­logical contacts, bedrock fractures, or valley floor environments.126 The type of water flow exhibited at individual spring sites is influenced by the hydraulic flow in the source aquifer and the geomorpho­logy of the spring site. The types and quantum of flow may also change with the seasons and over longer timeframes as a result of climatic change. There have been various attempts at classifying spring types, but the model adopted in the present study was based on the geomorpho­logy of the spring site.127 Based on this model, spring types within the study area included those associated with focused flow (gushet, cascade), hillslopes, established channels (rheocrene), hanging gardens, and fossil springs (palaeosprings), although individual spring sites may exhibit more than one flow type.128 Karst springs in Jarash Conglomerate, for example, typically feature gushet outlets in the calcretized crust in escarpments, with fissure and seepage outlets featuring in the geo­logical profile below the crust. Seepage flows in Kurnub sandstone in the southern Jarash valley are commonly associated with bedding planes and bedding/fracture plane junctions. Hillslope springs are common and occur at the boundary between permeable and less permeable rock units. The Na’ur, Fuheis, and Shueib Formations comprise layers of water-saturated permeable limestone alternating with less permeable marly horizons that act as aquitards. Springs often occur at the boundaries of these layers, which may lie within the formation or at the contact between formations. These springs can occur at any point in the terrain but, in gently dipping terrain, the intersection of litho­logical contacts with the sides 126  See Bryan 1919. For a detailed overview of the hydro­logy of springs, see Kresic and Stevanovic 2010. 127   For a recent classification of springs based on the geomorpho­logy of the source in the context of its ecosystem, and a comparison with other classifications, see Stevens, Schenk, and Springer 2020. 128  Stevens, Schenk, and Springer considered ‘paleosprings’ to be fossil, typically pre-Holocene, springs. Several springs in the study area probably fall into this category, but they are to be distinguished from ‘relict springs’, which are springs that were flowing in Antiquity or Late Antiquity but dried up prior to the nineteenth century.

Table 3.5. Spring classification according to discharge rates (after Bowen 2012, fig. 4.9). Spring Magnitude

Mean Discharge

First

>10 m3/s

Second

1–10 m3/s

Third

0.1–1 m3/s

Fourth

10–100 L/s

Fifth

1–10 L/s

Sixth

0.1–1 L/s

Seventh

10–100 mL/s

Eighth

100 L/s (Third  Magnitude)

3

Qairawan spring.135 Qairawan also maintained a strong flow during the summer months, with the minimum flow rate being 76 per cent of the recorded peak flow rate. These results reflect the dominance of conduit flow in the case of Maghasil and Birketein springs and the dominance of diffuse flow in the case of Qairawan spring. The more recent data in Table 3.6 indicate even greater variability in flow rates during the year. Maghasil and Birketein springs have become seasonal; Qairawan remains the strongest perennial spring in the district, but the recent minimum flow rate is well below that recorded in 1938–1939. The fact that the perennial springs with the highest summer flow tap aquifers towards the base of the Upper Cretaceous limestone sequence (e.g. Qairawan and Tannur) or in the underlying Kurnub sandstone (Shallal East) probably reflects the influence of leakage from overlying aquifers contributing to diffuse flow. Ionides provided Qairawan flow data for only a short period, and it is useful to study such data over a longer period in order to confirm aquifer behaviour and spring response. Figure 3.32 is a ­g raphical presentation of monthly flow rates from Qairawan spring over a ten-year period using data from Daane and McNeil, which range from 60–359 m3/hr.136 There is a noticeable delay in the spring’s response to winter rainfall, with the strongest flows generally occurring at the end of the rainy season or even early spring, confirming the responses shown in the Ionides data.

New Spring Discharge Estimates As published discharge figures were available for only a small number of springs, a matrix was developed within the study to provide an estimation of the relative strength of spring discharge (weak, moderate, and Figure 3.30. Diagrams showing flow rates for Maghasil, Birketein, and Qairawan springs in 1938–1939 based on single readings in each of the months shown, together with rainfall data for the same period. Drawn from data in Ionides 1939, 307.

135 

Ionides 1939, 278, fig. 3. and McNeil 1997. Flow rates were reduced to 30–300 m3/hr in the period 1993–2002 according to Parameswar and others 2004, table 1. 136   Daane

Natural Environmental Contexts

67

Figure 3.31. Bar chart showing a comparison of flow rates depicted in Figure 3.30.

Figure 3.32 (below). Bar chart diagram showing monthly flow rate record for Qairawan spring, November 1983 to August 1993. Drawn from data in Daane and McNeil 1997.

Chapter 3

68 Table 3.8. Relative discharge strength statistics (modern springs) in the context of aquifer source (* = rounded figures). Aquifer Jarash Conglomerate

Aquifer Recharge Area km * 2

Relative Discharge Strength of Spring

% Total Area

Included in Na’ur/Kurnub

Strong

Moderate

Weak

Subtotal

Springs per km2 of Recharge Area % Total Springs

6

0

5

11

4.1

1.6

Ghudran-Amman

1

0.5

0

0

0

0

0

0

Wadi as Sir

10

9.1

2

8

14

24

9.0

2.4

Shueib

10

9.4

5

5

19

29

10.9

2.8

Hummar

9

8.4

12

6

18

36

13.5

3.9

Fuheis

26

23.6

5

3

53

61

22.9

2.3

Na’ur

40

36.4

9

8

37

54

20.3

1.4

Kurnub

14

12.7

5

9

37

51

19.2

3.6

Totals

110.0

100

44

39

183

266

100.0

17

15

69

100

% of Total

Table 3.9. Relative discharge strength statistics (relict springs) in the context of aquifer source. Aquifer Name

Relative Discharge Strength of Spring Strong

Moderate

Weak

Subtotal

% of Total Springs

Jarash Conglomerate

4

0

3

7

16.3

Ghudran-Amman

0

0

0

0

0

Wadi as Sir

1

0

1

2

4.7

Shueib

3

0

0

3

7.0

Hummar

1

0

6

7

16.3

Fuheis

0

1

9

10

23.3

Na’ur

2

0

8

10

23.3

Kurnub

1

1

2

4

9.3

Totals

12

2

29

43

100.0

% of Total

28

5

67

100

strong) for each spring based on the scale of water use in three categories — irrigation, water storage, and domestic supply — plus a fourth category based on known mean discharge rates. These parameters were selected after a review of the available evidence (Table 3.7).137 The estimates are approximate only, given that the area irrigated depends on other factors such as soil availability and terrain. Colour Plate 3 shows the relative strength of spring discharges in the context of aquifer sources, and discharge strength statistics for modern and relict springs are tabulated in Tables 3.8 and 3.9, respectively. The background to this analysis and the implications in the context of the overall water management system are presented in Chapter 5. 137 

Boyer 2018d, table 5.3.

Relict Springs Although the number of relict springs identified may understate the total number that existed in the study area, some preliminary conclusions may be drawn from the available evidence. Their distribution is skewed towards a concentration below latitude 35.283°  N. in both the Jarash and Majarr–Tannur valleys, and their topo­g raphic locations — coupled with the evidence of very strong discharges in several instances — indicate that they were active in a pluvial climatic period that resulted in high rainfall and high water tables.

Discussion Modern spring distribution is uneven, with an overall concentration in the Jarash valley and a scarcity of springs on the west side of the Majarr valley. Springs are associated with each of the Ajlun Group limestone formations, even in strati­g raphic units such as the Fuheis and Shueib Formations that have been described overall as aquitards. Table 3.8 shows that the density of spring distribution within each formation is variable, with Hummar Formation springs having the greatest density and Na’ur Formation springs the least. Moderate to strong springs are also represented in each of these formations; however, 42 per cent of these springs are supplied from Hummar and Na’ur Formation aquifers. The concentration of stronger modern springs in the hills surrounding Suf reflects the greater distribution

Natural Environmental Contexts

69

Colour Plate 3. A representation of the relative strength of spring discharge (N = 322) in the context of aquifer source and the distribution of deeper soils (black). Satellite base map data, Google © 2016 CNES/Astrium; © 2016 DigitalGlobe.

Figure 3.33. Map showing the distribution of very strong springs. The inset shows the distribution of very strong springs in the city. Five-metre contours by Geoimage Pty Ltd. Reproduced with the permission of Geoimage Pty Ltd.

70

Chapter 3

Figure 3.34. Tectonic map and relief map showing the seismo­logical and topo­graphic setting of the Dead Sea Transform and surrounding areas. Adapted from [accessed 5 May 2017]. Public Domain.

of the Hummar, Shueib, and Wadi as Sir Formations in this area and higher aquifer recharge as a result of higher rainfall. Strong and moderate springs are uncommon in the southern Jarash valley, the upper Majarr valley, and the small drainages at the southern end of the study area, which severely limits the capacity for spring-fed irrigation in these areas. The large number of strong modern springs in the central Jarash valley is anomalous. This group includes the strong springs at Qairawan, Birketein, and Esh Shawahid that are discussed in Chapter 4 as being important sources for the aqueduct networks of the Roman and Byzantine periods. These springs, with the exception of Qairawan, were supplied by aquifers in Jarash Conglomerate. A subset of seventeen very strong springs has been identified based on an assessment of the available technical, historical, and archaeo­logical information (Fig. 3.33). The ‘strong’ and ‘very strong’ datasets both show a strongly skewed distribution in favour of the

Jarash valley. The very strong springs had a major influence on settlement locations in both valleys throughout history and influenced the placement of Gerasa’s Roman administrative centre on the west bank. The distribution of the forty-three relict springs shown in Table 3.9 is broadly similar to that of the modern springs, and the overall breakdown of relative strengths is also similar; however, it should be noted that the dataset is small and probably incomplete. The strongest relict springs all lie in the Jarash valley, where they are concentrated near Suf and Jarash. The low number of moderate and strong relict springs in the Majarr valley implies that agriculture in this soil-rich valley was essentially rain-fed in Antiquity, as is the case today. The relict springs are evidence of higher water tables, and the existence of aqueducts at several relict spring sites that were in use in the study period implies that the period of elevated water tables and stronger spring discharges at least partially coincided with the Hellenistic– Byzantine period.

Natural Environmental Contexts

71 logical evidence, and geotechnical and archaeometric data and has been the subject of intensive research and debate for decades.139 A review of the research shows that earthquake studies are fraught with challenges. Evidence from contemporary records, inscriptions, archaeo­logy, and geo­logy is rarely concurrent, and is often scant. Not all seismic events leave an obvious trace, and, as a consequence, the chrono­logical record is incomplete. The problem is compounded by archaeo­logical records that frequently lack the detail to distinguish destruction due to seismic events from destruction resulting from other sources such as warfare, looting, natural decay, or deliberate dismantling.140 The details of a number of major earthquakes are disputed, a point reinforced by the latest catalogue of major earthquakes in the vicinity of the Dead Sea Transform, which not only lists many new earthquakes but places the epicentre of the ad 749/50 events in northern Syria rather than Palestine.141 The distribution of well-attested major earthquakes in the Jordanian region in the period 31 bc to ad 1900 based on the latest published earthquake catalogue is shown in Figure 3.35. Earthquake Record in Gerasa

Background Figure 3.35. Map showing the epicentres of major historical earthquakes (movement magnitude Mw 5.0–7.7) associated with the Dead Sea Transform between 31 bc and ad 1900 in the Jordanian region and their locational uncertainty. Drawn from data in Grigoratos and others 2020.

Seismic History Seismo­logical Setting Gerasa lies c.  30  km east of the Dead Sea Transform (DST), a major north–south trending fault zone that extends 1200 km from the Red Sea to Turkey (Fig. 3.34). The DST comprises several fault segments, and the section lying closest to Gerasa is known as the Jordan Valley fault.138 Movement along the DST relieves stresses that build up in the adjacent rocks, and this relief manifests itself in the form of earthquakes that can be very severe. While the majority of earthquake epicentres lie within the DST, a few have been recorded in neighbouring areas that encompass the Decapolis. The earthquake record for the DST and the region has been compiled from an assessment of written historical sources, archaeo­ 138 

Ferry and others 2011, 39, fig. 1.

There is abundant indisputable geo­logical evidence of the impact of earthquake activity in the landscape in the study area, and earthquake effects have also been frequently observed in the archaeo­logy of the city ruins, but no comprehensive study of Gerasa’s earthquake history has been published to date.142 In Gerasa, the evi139  For the most recent studies, see Ken-Tor and others 2001; Ferry and others 2011; Yazjeen 2013; Wechsler and others 2014; ElIsa, McKnight, and Eaton 2015; Zohar, Salamon, and Rubin 2016; Grigoratos and others 2020. For an earlier study, see Russell 1985. 140   The late nineteenth-century Russian traveller Prince Abamelek-Lazarev observed ‘besides the earthquakes, wars frequently also turned thriving cities into heaps of ruins; and more destructive than weather on the ancient monuments has been the slow looting thereof. The following generations used them as raw materials for building new projects, and the denser the population, the higher the culture, the greater the luxury of the monuments of past times, the greater was the danger of the ancient monuments being destroyed’ (1897, 8) (translated from the original Russian). 141  Grigoratos and others 2020, 821–22. 142   For commentary on the geo­logical evidence of seismic impacts in the local landscape, see Boyer 2018d, especially 61–64. The city was one of several Jordanian sites included in an early study by El-Isa (1985). El-Isa provided a list of major earthquakes that affected the city and, unusually, estimated peak ground acceleration

Chapter 3

72

Table 3.10. List of earthquakes with Mw >5.0 within a 150 km radius of Gerasa between 33 bc and ad 750. Data from Grigoratos and others 2020, 823, table 4. Year (ad)

Month

Latitude 31.0

35.0

6.3

303

4

33.6

35.4

6.6

363

5

31.5

35.5

6.5

418

31.8

35.2

6.6

502

33.0

34.8

7.2

634

31.8

35.2

6.8

112

Longitude

Mw

659a

6

32.2

35.1

6.2

659b

9

31.9

35.5

6.0

747

1

32.8

35.8

7.0

The Archaeo­logical Evidence

Figure 3.36. Map showing the epicentres of major earthquakes (Mw >5.0) related to the Dead Sea Transform within 160 km of Gerasa in the period 33 bc to ad 750. Drawn from data in Grigoratos and others 2020.

dence from the study period is limited to geo­logical and archaeo­logical sources, but in addition to the earthquake research challenges already described, the reliability of the archaeo­logical evidence is further impacted by the paucity of earthquake strata in sealed contexts with well-dated chrono­logies and by attempts to attribute the evidence to a specific, regionally attested earthquake event.143 The epicentres of nine attested earthquakes within a 160 km radius of Gerasa in the period 33 bc to ad 750 with movement magnitudes (Mw) >5.0 are shown in Figure 3.36. The details of these earthquakes are presented in Table 3.10.

parameters, but the conclusions have been largely superseded by more recent research. 143  The only historical eyewitness record of an earthquake in Jarash relates to the January 1837 earthquake witnessed by George Moore and reported by Lindsay (1838, 107).

There are many references to earthquakes affecting the west side of the city in the published archaeo­logical corpus. The reliability, and hence the value, of the evidence in these references, varies considerably, so a simple matrix was established as follows to enable the data to be evaluated that took into account confidence that the damage/destruction was seismically induced, the existence of a sealed archaeo­logical context, and the chrono­ logical constraints. – High reliability: significant earthquake destruction, sealed archaeo­logical contexts, and reliable chrono­logy. – Medium reliability: significant earthquake destruction, some chrono­logical constraint, but sealed context doubtful or uncertain. – Low reliability: destruction not necessarily seismic-induced, no dating evidence or only vague chrono­logical constraint, no sealed context, or generally where there is uncertainty over the reliability of the data. The application of the matrix was to some extent subjective due to differing professional practices and levels of reporting detail, especially in pre-mid-twentieth-century excavation reports, compared to more recent reports. The references, including the seismic event attributions made by the respective authors, and an estimate of reliability derived from the matrix, are listed in Appendix E (Table  E.1), although references to undated or very vaguely dated earthquake events are excluded. The reliability assessment will no doubt need revision once final reports become available for excavations around the city. The results show that evidence supporting individual earthquake events is often poorly constrained

Natural Environmental Contexts chrono­logically, and evidence from sealed and welldated archaeo­logical contexts is available for only a few sites. The most reliable evidence relates to events in the mid-seventh and mid-eighth centuries; evidence of presixth-century earthquakes is both sparse and, with two exceptions, of low reliability. The higher proportion of references to the younger seismic events is influenced by factors such as the limited extent of excavation to Roman levels and the tendency for the foundations of later buildings to be taken down to bedrock, thus removing any evidence of earlier seismic damage. There is no published evidence of earthquake damage in the city before the third century; however, it has been speculated that the rebuilding of the North Gate in ad 115 followed an earthquake event in the early second century.144 If so, then the most likely event was the ad 112 earthquake with an epicentre west of the Dead Sea. The c. second-century plastering events recorded at several sites along the main north-west aqueduct ( JW01) in the present study may possibly reflect damage from the same event.145 Aside from damage to the NorthWest Quarter in the third–early fourth centuries, there is little reliable evidence of strong earthquake activity in the third- to the fifth-century period affecting buildings in the central part of the city, and although there are several attributions to the ad 363 earthquake episode, the evidence cannot be confidently attributed to any particular regionally attested event.146 The study found evidence of the ruination of columns on the Artemis Temple podium and the deposition of column drums onto the adjacent natural rock surface of the Artemis upper terrace that probably dates to the early period following the spoliation of the temple in the fourth–early fifth centuries.147 The ruination of structures on the west 144 

Russell 1985, 41. The construction was dedicated to Trajan in an inscription (Welles 1938, 401, nos 56–57). 145  Passchier and others 2021. 146  For commentary on the ad  363 earthquake, see Russell 1985, 42; Ambraseys 2009, 158–61. 147  The various building components of the Artemis Sanctuary are inconsistently described in the corpus. In Kraeling (1938a) and earlier publications of the Italian team investigating the sanctuary (for example Parapetti 1995), the terrace on which the Artemis podium and cella were built was referred to as the temenos or ‘temple terrace’ or ‘temple court’, and the terrace between the West Propylaeum and the temenos was referred to as the ‘intermediate terrace’. Temenos was later replaced by ‘upper terrace’ and ‘intermediate terrace’ was replaced by ‘lower terrace’. The use of upper terrace and lower terrace is adopted henceforth in this volume. The locations of these localities and others related to the Artemis Sanctuary are taken from Brizzi 2018, fig. 6.1.

73 side of the Nymphaeum and the subsequent construction of a quadriporticus on top of these ruins also appears to predate the mid-fifth century.148 These findings hint at the possibility that earthquake damage to the city in the fourth–early fifth centuries was more severe than previously supposed and may be associated with the ad 418 event that impacted Palestine.149 The most significant impacts on the city, and the southern Decapolis region as a whole, occurred in major seismic episodes that recurred at c. one hundredyear intervals between the mid-sixth and mid-eighth centuries, and in particular, the mid-seventh- and mideighth-century events. There is an increase in references to damage from the sixth century, and especially the mid to late sixth century, but the reliability is generally poor, and the destruction is limited in extent across the city. Some of this damage could conceivably have been associated with the major ad 551 earthquake episode, estimated to have had a movement magnitude of 7.5, which caused widespread damage along the Lebanese littoral and to a lesser extent inland, but the epicentre is c. 200 km from Gerasa.150 The collapse of the floor of the large reservoir (Reservoir 1; see Chapter 7) in the city’s North-West Quarter in the fifth or sixth century was likely caused by a substantial shock, but this damage has not been attributed to a specific seismic event by the excavators.151 Earthquake events in the seventh century caused widespread and well-documented damage across the city between the Hippodrome and the West Propylaea. Evidence from the Macellum and Propylaea Church is considered to be reliable and is attributed by the excavators to earthquake events in ad 633 or ad 659/60, but the majority of excavators attribute the earthquake damage to the so-called ad 659/60 seismic episode.152 This episode is now considered to have comprised two sepa148   For details of the excavation of the area west of the Nymphaeum, see Brenk 2015. 149  For discussion of the ad 418 earthquake, see Ambraseys 2009, 162. It is worth noting that the geo­g raphic locations of the epicentres for the ad 363 and ad 418 earthquakes are similar; see Grigoratos and others 2020, 823, table 4. 150  For commentary on the ad  551 earthquake, see Russell 1985, 44–46; Darawcheh and others 2000; Sbeinati, Darawcheh, and Mouty 2005, 357–59; Ambraseys 2009, 199–203; Grigoratos and others 2020, 821. 151  Lichtenberger and others 2015, 120–23. 152  See Russell 1985, 51–55, but cf. Ambraseys 2009, 221–22. For details of the ad 633/34 earthquake, see Sbeinati, Darawcheh, and Mouty 2005, 360; Ambraseys 2009, 219–20.

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74 rate events two days apart in June ad 659 that affected Palestine and, to a lesser extent, Syria. 153 Although there appears to be no support for this event affecting the Decapolis from literary sources, there is convincing archaeo­logical evidence for earthquake damage around the mid-seventh century for the western side of the city. The effects of earthquakes in the mid-eighth century were felt in all the cities of the southern Decapolis, and there is substantial evidence of earthquake damage in Gerasa related to these events. The Gerasene references attribute the damage to events that range in date from ad 717 to ad 749. While the majority of the more recent references attributed the damage to an event in January ad 749, the evidence only supports an approximate mideighth-century date and does not preclude the possibility of several separate but closely spaced events. Tsafrir and Foerster argued that events previously dated to ad 746/47/748 actually refer to a major event in January ad 749;154 however, the matter is not settled, as is shown by evidence for three separate seismic episodes affecting the region between ad 746–757.155 The Gerasene sites with damage from the mid-eighth-century seismic episode are found throughout the excavated parts of the western side of the city, and the reliability of the evidence is medium to high in the majority of cases. While evidence from the South-West Quarter is sparse for the study period, it seems likely that the mid-eighth-century earthquakes affected the entire western side of the city. Particularly reliable evidence is available for sites in the North-West Quarter and in the South Decumanus– South Tetrakionion precinct, where the suddenness of earthquake impact on domestic life is dramatically represented in the archaeo­logical record.156 Evidence from the eastern side of the city is currently limited to two sites. The first site was identified in the study adjacent to the substructio carrying the Qairawan aqueduct. The site ( JWP111) was briefly exposed during foundation exca153   See Russell 1985, 46–47; Ambraseys 2009, 221–22. Grigoratos and others (2020) found evidence of an earthquake event (H659b) with a different epicentre in September ad 659. 154   For a comprehensive commentary on the mid-eighthcentury earthquakes, see Ambraseys 2009, 230–38. See also Russell 1985, 47–49; Tsafrir and Foerster 1992; Marco and others 2003; Sbeinati, Darawcheh, and Mouty 2005, 362–64. 155  See Ambraseys 2009, 234–38; Grigoratos and others 2020, 821–22. 156  For evidence in a shop beside the South Decumanus, see Walmsley 2007, 259–61. For evidence in the North-West Quarter, see Jørgensen 2018: Lichtenberger and Raja 2019e. For similar evidence in Pella, see Walmsley 2007.

Figure 3.37. Archaeo­logical and 14C dating evidence of earthquake tumble beside the Qairawan aqueduct substructio at site JWP111.

vations for a new building, and radio­carbon dating of charcoal from horizons above and below a tumble horizon up to 2 m thick over a low, ruined masonry structure (possibly an early water channel) indicated that the tumble dates to the mid-eighth century period (Fig. 3.37). The second site is the Large East Baths, where earthquakes are said to have caused ‘a brutal and almost complete destruction of the monument’.157 Whatever the actual date of the seismic episodes of the mid-eighth century, the damage they caused was substantial. The massive damage to the Large East Baths and the damage evidenced in domestic buildings around the South Tetrakionion and the North-West Quarter show that buildings both large and small were dramatically affected. Evidence from the North-West Quarter shows that this part of the city was devastated and abandoned after the mid-eighth-century earthquakes and not reoccupied until the Ayyubid–Mamluk period; 158 however, evidence from the vicinity of the Umayyad Congregational Mosque in the central city area shows that this part of the city was resettled shortly after these earthquakes.159 The catalogue published by Grigoratos and others includes many significant seismic events (i.e. M w > 6) in the region after the mid-eighth century. Earthquake damage has been identified in the city’s South-West Quarter dating to the late ninth–early tenth centuries,160 157 

Lepaon, Turshan, and Weber-Karyotakis 2018, 140. Lichtenberger and Raja 2018a, 163; 2019a, 277–92. 159  Rattenborg and Blanke 2017, 319–24. 160  Blanke 2017. 158 

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Figure 3.38. Photo­graphs of the basilica of St Theodore’s Church during excavation showing the orientation of fallen columns. (a) London, UCL, StTheodore_9_141 17620127_5f4c4c81a9_o.jpg; (b) London, UCL, StTheodore_23_1441 3273846_98ed97777f_o.jpg. © UCL, Institute of Archaeo­logy.

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Figure 3.39. Examples of the impacts of horizontal shear stress on columns. (a) and (b) The colonnade surrounding the Oval Piazza; (c) Columns on the podium of the Artemis Temple.

and Seigne and Tholbecq attributed a destruction layer on the lower terrace of the Zeus Temple to an earthquake around ad 1200.161 As already noted, an earthquake affecting the city in January 1837 was witnessed by a European visitor, George Moore. 161 

Rasson-Seigne, Seigne, and Tholbecq 2018.

The clearances of the 1920s and 1930s and subsequent building restorations have removed much of the visible evidence of structural damage to buildings in the city; however, there is sufficient evidence from historical photo­g raphs and from surviving unrestored buildings to provide an overview of the types of damage incurred. Large-scale damage in the form of groups

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Figure 3.40. Examples of seismically induced column capital rotation from the colonnade surrounding the Oval Piazza. (a) c. 70 degree rotation; (b) c. 20 degree rotation.

of columns falling in the same direction was revealed in the excavation of St Theodore and Synagogue Churches by the Yale Mission (Figs  3.38a–3.38b), and similar evidence has been reported from churches elsewhere in the Decapolis.162 Smaller-scale impacts of horizontal shear stress on columns are preserved in the colonnades surrounding the Oval Piazza and on the Artemis podium (Figs  3.39a–3.39c), and there are also examples of the vertical rotation of Ionic capitals of up to seventy degrees in the western colonnade of the piazza (Figs 3.40a–3.40b). 162 

The collapse of the columns in the so-called Cathedral of Hip­pos is particularly striking; Wechsler and others 2018, 19, fig. 2.3.

Mortar was rarely used on the larger city buildings, and there are many examples of seismically induced block separation, especially in masonry pilasters and columns (Figs 3.41a–3.41b). Seismically induced shearing is also evident across ashlars in extensive walls such as those forming the Artemis cella (Fig. 3.41c). The Buttress Walls of the Nymphaeum

By the Late Byzantine period, the city had experienced several major earthquake episodes, and the populace would have been well aware of their damaging effects. In the case of the Nymphaeum, the risk of further damage was mitigated by the construction of buttress walls on the northern and possibly also the southern eleva-

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Figure 3.41. Examples of seismically induced block separation. (a) The Western Propylaeum. London, UCL, Propylaea-25_14249829098_ afbec850c5_o. © UCL, Institute of Archaeo­logy; (b) The North Decumanus colonnade; (c) Block separation and shearing (arrowed) in the outer west wall of the Artemis cella.

Natural Environmental Contexts

Figure 3.42. Nymphaeum buttress wall construction phases. (a) and (b) The north wall of the Nymphaeum. © Jarash Water Project; (c) The south wall of taberna. Creative Commons Attribution-Share Alike 4.0 International, CC BY-SA 4.0; (d) Vertical view of the walls shown in (a) to (c). After APAAME_20081029_RHB-0154, photo­grapher R. Bewley, courtesy of APAAME.

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Figure 3.43. Views of the buttress walls on the southern elevation of the Nymphaeum. (a) and (b) Modern views; © Jarash Water Project; (c) Historical photo­graph, c. 1931. Yale University Art Gallery, Gerasa Collection, Negative C21 C-21 (a detail). Reproduced with permission.

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Figure 3.44. Stylized block diagrams of various land-movement types. [accessed 5 May 2017]. Public Domain.

tions of the monument, and these walls are well preserved. Similar buttress walls were also built against the southern wall of the southernmost taberna across the laneway (the so-called Museum Street) to the north of the Nymphaeum, but such walls do not appear to have been common in the city. The original Nymphaeum was a two-storey structure with a relatively slender profile that was built on the corner of the Cardo and Museum Street by ad 190–191.163 The lack of excavation to the rear of the Nymphaeum means that nothing is known of structures built against it on the west elevation, but, contrary to the findings of the Yale Mission, the Nymphaeum was not originally joined to second-century rooms to the south.164 The Nymphaeum’s central semicircular façade was reasonably well protected against earthquake stress by thicker walls and flanking lateral projecting wings, but the lateral wings themselves had thinner walls that supported huge masonry pilasters and were less well protected. 163   See the description of the Nymphaeum (fountain 6) in Appendix I. 164  Plans from the Yale Mission show that in the second century the Nymphaeum was joined to ‘Room 18’ to the south that formed part of the second-century propylaeum of a temple that was later replaced by the Cathedral in the mid-fifth century (Crowfoot 1938, 203, plan XXIX). This presentation is misleading, as even a cursory field examination shows that the northern wall of ‘Room 18’ that abutted the southern wall of the Nymphaeum does not date to the second century but is much later (probably late Byzantine). This later wall abuts the west wall of Room 18, which is probably second century, but does not interleave with it. When built, the Nymphaeum was separated from Room 18 by a horizontal distance of c. 1 m.

This exposure was later demonstrated by severe damage to upper storeys of both lateral wings above the level of the buttress walls yet much of the façade interior undamaged. The evidence suggests that the buttress walls were built in two stages. In the first stage, a well-constructed spolia wall of hard limestone ashlars, including one block with a second–third-century inscription, was added to the northern elevation.165 In the second stage, a thicker, less well-constructed wall of large nari blocks was built against the earlier stage 1 wall of the Nymphaeum, and a similar wall was built against the original southern wall of the taberna on the north side of Museum Street (Figs 3.42a–3.42d). The importance of the work can be deduced by the fact that the second phase walls reduced the width of Museum Street from 5.3  m to 3.8 m. The wall abutting the original southern wall of the Nymphaeum may also have been built in the second stage (Figs 3.43a–3.43c). The timing of the building of the buttress walls is currently uncertain: it seems likely that the first support wall was added after a seismic event had impacted the city and demonstrated the damage risk to the monument, and on present evidence, it appears that the first strong earthquake impacts were in the fourth/fifth centuries. The inscribed blocks included in the wall as spolia provide a second/third-century terminus ante quem. Brenk, Bowden, and Martin suggested that the first stage wall on the northern elevation of the Nymphaeum was part of a reconstruction of the area 165 

Welles 1938, 407, no. 70.

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Figure 3.45. Examples of toppling damage to bedrock agricultural installations adjacent to escarpments. (a) and (b) Toppled press installation at site JWP154, c. 700 m north-west of the Jarash; (c) and (d) Toppled basin at site JWP153, Bab Amman.

west of the Nymphaeum carried out in the first half of the fifth century.166 From the available evidence, it is speculated that the building of the first and second phase buttress walls was triggered by damage to the Nymphaeum caused by the seismic events of the fourth/fifth centuries.

Earthquake Impacts in Gerasa’s Hinterland: The Geo­logical Evidence The earthquakes that impacted the city also impacted the city’s hinterland and the water infrastructure within it. The few published archaeo­logical investigations conducted outside the city prior to the present study have not provided any dated evidence of earthquake activity. There is considerable geo­logical evidence attesting to a long history of seismic activity scattered through the landscape, although the evidential traces have faded as a result of landscape change brought about by weathering and human activity. 166 

See Brenk, Bowden, and Martin 2009.

Shaking associated with seismic events causes surface faulting and may trigger ground failure in the form of various downslope earth movements that are shown in Figure 3.44. The largest earth movements are landslides, and many were recorded in the study area during the geo­logical mapping conducted by the Jordanian government, but they are more common than the mapping suggests.167 Seismically induced rock falls and topples can be found associated with most natural cliffs and escarpments throughout the study area, and especially along landslide back scarps. There are several examples where these falls have damaged bedrock agricultural installations (Figs 3.45a–3.45d), but aqueducts constructed close to the edge of escarpments were particularly affected by this form of seismic damage (Figs 3.46a–3.46e). Some types of earth movement can be triggered by heavy rainfall as well as seismic events, but seismic events 167 

Abdelhamid 1995.

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Figure 3.46. Examples of damage to aqueducts constructed on the edges of escarpments. (a) Toppling damage, Birketein, site JWP145; (b) Fracturing, north-west aqueduct, site JWP127 (Horizontal Scale 0.5 m); (c) Fracturing, north-west aqueduct, site JWP115 (scale 0.5 m); (d) and (e) Toppling and fracturing damage, site JWP152.

exacerbate the risk of landslides occurring in susceptible areas. The combination of steep slopes and unstable marl and clay units within the bedrock sequence has created a local landscape susceptible to earth movements. This particularly applies to areas underlain by the Upper Cretaceous Shueib Formation in the north-western part of the study area and on steep slopes adjacent to the wadi at lower elevations, especially in areas underlain by Lower Cretaceous Kurnub Formation sandstone. Recent landslide research in the vicinity of the Amman–Irbid highway classified much of the southern Jarash valley and the lower part of the Tannur valley in the vicinity of the highway as ‘highly susceptible’ to landslides (Fig. 3.47a), and significant sections of the wadis were classified as ‘very highly susceptible’ (Fig. 3.47b).168 The 168 

Awawdeh, El Mughrabi, and Atallah 2018.

‘very highly susceptible’ areas in the Jarash valley south of Shallal are underlain by Kurnub sandstone and have been rendered unstable by numerous small springs on steep slopes and the undercutting of banks by wadi erosion and road construction, but research has shown that the key landslide trigger-mechanism in the area since the mid-twentieth century has been heavy rainfall.169 Aerial images reveal evidence of many landslides that impacted directly on slopes and infrastructure beside the wadi and often on the course of the wadi itself. The absolute dating of individual landslide events was not attempted in the study; however, the geo­logical evidence suggests that landslides have been a feature since the earliest stages of landscape development and continue to occur today. Seismic events in Antiquity or pos169 

Farhan 1999.

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Figure 3.47. Maps showing landslide susceptibility in the southern Jarash valley. (a) Areas highly susceptible to landslides; (b) Areas very highly susceptible to landslides. Drawn from data in Awawdeh 2018.

Figure 3.48. Map showing landslide events in the southern Jarash valley in the vicinity of the Der Abu Saedi locality interpreted from a 1930 aerial photo­ graph. Adapted from Oxford, EAMENA, Jordan Valley Aerial Survey Archive, 45B Squadron, Frame 10476, 1030. Courtesy of EAMENA.

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Figure 3.49. Views of the southern end of the historical Bab Amman landslide on the eastern slope of the Bab Amman mesa. (a) 1953 vertical aerial photo­graph of site. Adapted from Stott, Raja, and Lichtenberger 2018; (b) Modern oblique aerial view of the site. Adapted from APAAME_20101021_DDB-0399, photo­grapher D. Boyer, courtesy of APAAME.

sibly earlier are likely to have been the cause of a cluster of landslides over a distance of c. 1 km in the vicinity of the Der Abu Saedi locality, 3 km south of the city, that changed the course of the wadi (Fig. 3.48). Closer to the city, a well-preserved example of a translational landslide on the west bank of Wadi Jarash in the Bab Amman locality (hereafter, the Bab Amman landslide) involved the detachment of a c. 500 m long section of the eastern side

of the Bab Amman mesa at site JWP147 and resulted in the dislocation of a group of rock-cut aqueducts supplied from Qwndeit spring (Figs 3.49a–3.49b). At least part of the backscarp of this landslide follows a line of weakness created by one of the aqueducts cut into the bedrock. The landslide has not been dated in absolute terms, but the weathering of the backscarp and lateral scarps, the rock falls along these scarps, and the existence of signifi-

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Figure 3.50. Views of the historical Wadi Suf landslide at site JWP194. (a)  Interpretation of satellite imagery. Satellite base data, Google Earth, © 2021 CNES/Airbus; (b) Ground view, looking east, showing site JWP194 at the foot of a forty-degree slope.

cant colluvial accumulations on top of the landslide is taken to be evidence that it probably dates to Antiquity. An unusually well-preserved section through a debris flow in a historical landslide is visible in a cut in the south bank of Wadi Suf at site JWP194, west of Mukhayyam Suf (hereafter, the Wadi Suf landslide). The site lies at the foot of a forty-degree slope, and the flow may have originally engulfed the wadi bed at this point. An overview of the landscape setting is shown in Figures 3.50a–3.50b, and details of the profile through the

bouldery front of the debris flow are shown in Figures 3.51a–3.51b. The debris flow was deposited on a seemingly undisturbed palaeosol. This sequence is currently undated, but evidence of a ‘rubble slide’ of Yarmoukian (Pottery Neolithic) date overlying PPN strati­g raphy at Tell Abu Suwwan suggests that there is a long history of this type of deposition in the area.170 See Weninger and others 2009, 30–33. The c. 1 m thick Tell Abu Suwwan deposit was one of several examples identified in 170 

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Figure 3.51. A sectional view through a historical debris flow lying on a palaeosol within the Wadi Suf landslide; Wadi Suf, site JWP194. (a) General view of wadi bank, looking south; (b) Detailed section through the debris flow.

Not all landslides are the result of seismic activity. Studies of recent landslides that affected the Amman– Irbid highway in the southern Jarash valley highlighted the combined impact of heavy rainfall, especially heavy rainfall events that can result in swelling and instability in claystone layers, fractured bedrocks, high drainage density, and the undercutting of unstable slopes by road Jordanian Neolithic sites.

construction.171 An example of a rotational landslide is shown in Figure 3.52a, and a (?)translational landslide associated with a fault down the slope at Jarash Bridge is shown in Figure 3.52b.

171   See Awawdeh, El Mughrabi, and Atallah 2018. For a discussion of the causes of landslides in Kurnub sandstone, see also Malkawi and others 1998, 19.

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Figure 3.52. Examples of landslides in the Jarash valley. (a) The Er-Rashayida rotational landslide beside Amman–Irbid highway south of Jarash: the landslide occurred in the winter of 1991–1992. APAAME_20170927_DDB-0282, photo­grapher D. Boyer; (b) Translational landslide at Jarash Bridge on the Amman highway: the landslide occurred in January 2017. APAAME_20170927_DDB-0272, photo­grapher D. Boyer. Courtesy of APAAME.

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Discussion Good soils, an agreeable climate, and the existence of many natural springs are factors that gave local settlers options not commonly available elsewhere in the Near East, and the long human record of use and occupation reflects this relatively benign physical environment. The variability and seasonality of rainfall are notable factors in the current climate regime and, as shown from the study of carbonate sediment lining an aqueduct, were also factors in the Roman period. The steep easterly rainfall gradient directly impacts aquifer recharge and the number of springs and, together with the amount of water available for rain-fed agriculture, largely account for the very different settlement patterns in the two neighbouring valleys described in the next chapter. The geo­logy of the area has had a profound impact on human activity. The physical characteristics of the various limestone and nari units and their ready accessibility resulted in the extensive use of locally quarried stone for building construction from at least the Hellenistic period onwards. Outcropping limestone ‘pavements’ formed runoff fields used for rainfall harvesting, and natural solution cavities or caves converted into cisterns stored the runoff. Caves are commonly developed in Na’ur limestone and Jarash Conglomerate and have been used for dwellings since prehistoric times. There are many examples of caves in Jarash Conglomerate being used for cisterns or converted into tombs in the city’s vicinity. Surface runoff played a role throughout the study period, particularly in domestic contexts and in rural areas distant from spring sources, but, by the Roman period, spring sources supplied the city and many rural parts of the Jarash valley. There is little evidence of the use of wells tapping the water table, and the availability of spring water largely obviated the need for wells. The area has a high density of springs, but the study results emphasize the overwhelming importance of the

distribution of strong and very strong springs in determining settlement locations — including Gerasa itself — and the placement of irrigation distribution networks. The seasonal variation in spring flows highlights challenges that would have necessitated tight control of scarcer water resources in the dry season in the study period, as is the case today. The extant evidence points to seismicity having an enduring impact on the lives and activities of the inhabitants, and in particular on the water infrastructure, throughout the historical period. Earthquakes in the fourth century may have had a more significant impact on the city area than previously supposed, but the bestattested events are in the mid-eighth century. An interpreted chrono­log y of landscape-forming events suggests that the main landscape characteristics in the central Jarash valley were established by the end of the Pleistocene. These events included phases of wadi erosion and landslides. Since then, weathering and depositional events have smoothed the topo­graphy and partially infilled the wadis, and climatic changes have resulted in lowered water tables and the loss of some springs, while landslides continue to be a problem in the southern Jarash valley. Climatic changes in the Byzantine period resulted in the deposition of waterborne colluvial gravels in cities throughout the Decapolis. In Gerasa, these gravels were accumulating in the lower part of the western side of the city by the fifth century but became more significant in the fifth to the early seventh centuries and appeared to have contributed to the abandonment of the North Decumanus precinct, emulating similar circumstances in Pella. Climatic conditions triggered debris flows in Abila in this period, and there is evidence of debris flows invading Wadi Jarash south of the city and burying water infrastructure in the vicinity of Ficus Springs.

Figure 4.1. Examples of primitive agricultural installations. (a) Bedrock mortars (crushing basins) from the Early Bronze–Middle Bronze Age site of Khirbet Mansub, Wadi Tannur (scale 1 m); (b) Bedrock mortars from a hilltop north-east of the village of Al-Kufahr, on the eastern watershed of the Majarr–Tannur valley (scale 20 cm); (c) Primitive olive press, Khirbet Mansub (scale 20 cm). (d) and (e) Primitive portable olive press, central Jarash valley (scale 10 cm). Courtesy of Jarash Hinterland Survey.

Chapter 4

Historical Contexts Introduction The study area has a settlement history that encompasses the period from the Palaeolithic to the present day. Our knowledge of this history is based on two main information sources; archaeo­logical excavation and surface surveys. Even when combined, these sources provide only fragmentary coverage of a landscape containing hundreds of occupational sites spanning many periods that are poorly documented.1 The urban evidence from excavation comes mainly from the west side of the city, as the ruins of the eastern half of the ancient city are overbuilt by the modern town of Jarash. Outside the city, the main published excavations relate to the Birketein precinct 1.4 km north of the city,2 but excavations were also conducted at the Christian monastery at Khirbet Munya near the village of Asfur,3 and the Roman fort (‘Tell Faysal’) near the junction of Wadi Jarash and Zarqa River.4 Evidence is presented to show that the area’s settlement history has been underpinned by agro-pastoral production. Initially a subsistence economy, activities were later expanded as the area grew in prosperity, and the surplus was used in the manufacturing of goods for local consumption and trade or processed on a commercial scale into olive oil and wine that was also traded. The wealth generated by these activities sustained the local civic organization and infrastructure throughout the Roman–Early Islamic period. A detailed study of rural activities in the study area is outside the scope of this volume, but it is desirable to discuss settlement history in the context of the activities pursued in and around the settlements. From humble sedentary beginnings in the Neolithic period, these activities, especially arable farming, grew progressively in scope and sophistication but — as today — were always constrained by the terrain, soil and water resources, and the prevailing climate. 1  For overviews of the occupational history, see Boyer 2018a, 226–28; 2018d, 72–75; Kennedy 1998; 2000; 2004; 2007. 2  McCown 1938a. 3  Piccirillo 1983. 4  Palumbo and others 1993.

Pastoral activities are likely to have been concentrated in upland areas, especially in the steppe lands where cultivation options are limited by thin stony soils and less reliable rainfall, although the evidence of ancient terracing in these upland areas shows that cultivation was, at times, widespread when soil and rainfall were available in sufficient quantities. These activities, especially those by nomads, leave little direct evidence, although Jean Sapin identified possible travel routes of nomads in the hills to the east of the Majarr–Tannur valley watershed.5 In contrast, direct evidence of cultivation in the study area comes from the widespread use of constructed terraces and field boundaries.6 Evidence of the crops grown comes from rock-cut pressing and crushing installations, small-scale artefactual evidence, inscriptions, and faunal/botanical remains found at occupation sites. All these pieces of evidence guide an understanding of spatial distribution and organization. Faunal remains evidence from Tell Abu Suwwan indicates that activities in the Neolithic included animal husbandry and hunting, and cereal growing is deduced from the discovery of burnt grains, grinding stones and flint sickle blades.7 Regional evidence from the Ajlun district shows that olive cultivation had its beginnings in the late Neolithic period and was well established during the Chalcolithic period.8 The proliferation of small but undated, primitive rock-cut press installations in the vicinity of prehistoric sites in the study area points to the widespread cultivation of orchard crops. Examples of bedrock mortars and primitive press-bed installations were observed during the field survey (Figs 4.1a–4.1e), 5 

See Sapin 1998. For commentary on cultivated terraces and field walls, see Sapin 1998. 7  See Al-Nahar 2010; 2013b; 2018. Neolithic bedrock mortars were also identified at Tell Abu-Suwwan; see Al-Nahar 2010, 9. 8   See Lovell, Meadows, and Jacobsen 2010; Ali 2019. The earliest rotary crushing mill in the study area known to the author predates the second century ad and was found in a cave just outside the south-eastern part of the city wall: see Iliffe 1945, 1. For a broader study of the spread of olive cultivation in the Mediterranean area, see Langgut and others 2019. 6 

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Figure 4.2. Early bedrock agricultural installations. (a) Portable olive press bed, Muqbila, Jarash valley; (b) and (c) Portable Olive press beds, North-West Quarter of the city; (d) Press bed and vat, Khirbet esh Shawahid, Jarash valley; (e) Press bed and vat, site JWP174 Jarash valley.

Figure 4.3. Examples of olive mill installations. (a) Rigid frame olive press bed, cave in Room A-24, west of St Theodore’s Church. Yale University Art Gallery, Gerasa Collection, Negative A61 A-61. Reproduced with permission; (b) Rotary crushing installation, cave 5 west of St Theodore’s Church. Yale University Art Gallery, Gerasa Collection, Negative JerashSeriesB-B-43 B43. Reproduced with permission; (c) Rotary crushing installation beside the city’s South Gate; (d) Lever press component and (e) rotary crushing stone in cave, El Hute, near site JWP133, Majarr–Tannur valley, scale 20 cm. © Jarash Water Project; (f ) Cross-type olive screw press, Khirbet Zaqrit; (g) Press-bed and vat installations at the Khirbet Zaqrit oilery, 1.8 km west of the city. Courtesy of the Jarash Hinterland Survey.

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Figure 4.4. Examples of larger winery installations. (a) Single 24 m2 treading floor with double rectangular vats, Khirbet esh Shawahid, site JWP124, Jarash valley; (b) Part of a winery complex, showing several treading floors and vats, site JWP180, Majarr Tannur valley; (c) Lever press with 6 m2 treading floor and vat, site JWP170, Jarash valley; (d) Treading floors (largest 7 m2) beside bell-shaped vat (c. 25 m3 capacity), site JWP134, Majarr–Tannur valley; (e) Commercial-sized winery at Khirbet Ain Riyashi, site JWP150, Majarr–Tannur valley. (TF = Treading floor; V = Vat; Long pole is 2 m.)

and, over time, these installations became more sophisticated although still small (Figs 4.2a–4.2c). The dating of the introduction of domesticated grapevines in the Jarash area is uncertain, but wine production is attested from at least the Bronze Age at sites west of the Jordan River. 9 Initially, winery installations were modest in size, having a single pressing floor and vat, and such installations may also have been used for pressing olives (Figs 4.2d–4.2e).10 The introduction of commercially sized rotary crushing mills in Gerasa by the second century was part of a regional trend. Olive cultivation peaked in the 9  See Frankel 1997, 74. For recent genomal research on the introduction of grapevines into the southern Levant, see Sivan and others 2020. 10  See Frankel, Avitsur, and Ayalon 1994, 31; Frankel 2009, 2. For a regional, multiperiod study of wineries and oil presses, see Ayalon, Frankel, and Kloner 2009.

Hellenistic–Byzantine period but remains an important activity in the district to this day.11 Examples of ancient oil crushing installations in underground (cave) locations from the study area are shown in Figures 4.3a–4.3g. Viticulture saw a similar expansion in the Roman–Byzantine period, as evidenced by the number of larger installations (Figs 4.4a–4.4d) and commercialscale wineries (Fig. 4.4e).12 The existence of crop processing installations gives a general indication of local farming activities, a theme that is discussed further in Chapter 8 in connection with irrigation. A third-century inscription from the ‘gardeners of the upper valley’ is a rare example of an inscription 11 

Schiebel and Litt 2018. importance of vineyards in the third century is underlined in an edict found near Gerasa outlining penalties for vineyard pillagers: see Johnson, Coleman-Norton, and Bourne 1961, 230. 12   The

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Colour Plate 4. Sites recorded in surveys in the period 1895–2012. Satellite base map data, Google © 2016 CNES/Astrium; © 2016 DigitalGlobe.

providing evidence of the location of specific farming activities.13 Details drawn from the early Ottoman tax registers provide additional comparative information on agricultural production in the area. 14 The register of ad 1596/97 is particularly interesting in that it refers 13   For

the inscription, see Gatier 1985, 310–12. Gatier considered that the inscription referred to a steep-sided valley or ravine, and he suggested that these gardens lay in the vicinity of Birketein. The author considers that it may equally refer to any part of the valley upstream of the city. The rich El-Hammar plain between the city and Birketein is the likely location, an area that even today is given over to intensive cash crop cultivation when irrigation water is available. 14  See Hütteroth and Abdulfattah 1977; Peterson 2018.

to taxes raised from goats/beehives and the growing of wheat and barley, with almost half of the taxes raised coming from a broad category that included ‘summer crops’, olives, vineyards, and sesame. Grains were ground in local watermills.

Surface Surveys Raw data on the occupational history of the area outside the city come from the various published surveys described in Chapter 1. The site details gathered in these surveys vary considerably in detail and accuracy, and there is often confusion and inconsistency in their naming and location. In nearly all cases, the dat-

Historical Contexts ing of the site is based on surface sherd scatters rather than archaeo­logical excavations. An important question is whether the surveys were comprehensive and representative enough to support the conclusions made by their authors, and some earlier conclusions based on ceramic typo­logy have been questioned in light of recent advances in this discipline.15 Glueck pioneered the use of ceramic typo­logy to date sites in regional surveys, but his geo­graphic coverage was uneven, and the accuracy of his work and the validity of his conclusions have been questioned in light of recent research.16 The uneven geo­g raphical coverage of the regional surveys conducted between the 1930s and 1990s is not limited to Glueck’s work and is evident when the localities visited during this period are plotted onto a single plan (Colour Plate 4). The uneven overall coverage reflects the deliberately focused surveys conducted by Leonard and Sapin, but it also reflects the selective and unsystematic nature of the earlier regional surveys by Glueck and Mittmann and the limited geo­graphic scope of Hanbury-Tenison’s survey. Glueck’s and Mittmann’s surveys were influenced by the availability of tracks and roads, while Mittmann’s approach was influenced by a belief that hilltops were not generally used as occupation sites in karst terrain.17 Glueck and Mittmann left large areas of the Jarash and Wadi Majarr valleys unsurveyed, a situation that was only partly remedied by the subsequent surveys conducted by Leonard and Sapin. This is where the earlier work conducted in the region by Schumacher in 1894–1900 becomes relevant.18 Schumacher’s contribution to regional survey knowledge has traditionally been ignored, and his work was severely criticized by Albright,19 but the fact remains that his ground coverage exceeded the combined coverage of the later regional surveys, with sixty sites being recorded in the study area. Schumacher did not employ ceramic typo­logy to date his sites, but his work provided unparalleled insights on many sites not recorded before or since, as well as a wealth of general geo­g raphical observations in the period when Circassian settlement in the area — and the attendant landscape changes — had not

15 

See Bradbury, Braemer, and Sala 2014. For a critique of Glueck’s conclusions, see Schaub 1992. 17  Mittmann 1970, 106. 18  Schumacher 1902. For the edited notes of Schumacher’s surveys in the Hauran and northern Transjordan, see Steuernagel 1924; 1925; 1927. 19  Albright 1926. 16 

95 long been established.20 Schumacher also made particular note of springs and water installations. When his sites are combined with those recorded by the other surveys, the gaps where no sites have been recorded are reduced but still amount to almost 60 per cent of the study area. AP/satellite image interpretation and field surveys conducted during the present study show that unrecorded occupation sites exist in these gaps, and the published results and data based on the original low-intensity regional surveys, especially those in the Jarash valley, are therefore considered to be skewed. The efficacy of the regional surveys in identifying settlement sites can only be demonstrated by more intensive field surveys, a point reinforced by Sapin’s more intensive surveys that identified significantly more occupation sites in the Majarr– Tannur valley than had been found in previous surveys.21

Settlement History The study considers water management up until the end of the Umayyad Caliphate; however, the bulk of the evidence in this volume relates to the Late Hellenistic– Umayyad period, and the discussion of the settlement history also focuses on this period.22 Pre-Bronze Age Aside from the hypothesis that the flint lithics in the Jarash Conglomerate at Bab Amman may be contemporary with the Lower Pleistocene hominin flint lithics recently identified in the Dawqara Conglomerate in the Upper Zarqa, there is evidence of various Pre-EBI settlement sites in the study area.23 Lower Palaeolithic (Middle Acheulian) flint implements collected from the Bab Amman-Tell Abu Suwwan locality south of Jarash in the late 1940s are the earliest attested evidence of a hominin presence, while evidence of a later Epipalaeolithic– Neolithic presence within the study area is also sparse.24 20 

Ceramic typo­logy was introduced in Palestine in the 1890s by Flinders Petrie at the time that Schumacher was conducting his surveys and was not in general use — see Lehmann and Niemann 2006, 670. 21  See Sapin 1998, 120. 22   For a recent diachronic review of urban occupation and construction activities in the Hellenistic–Umayyad period, see Seigne 2019a. 23  For a plan showing the distribution of pre-EBI sites, see Boyer 2018d, fig. 5.16b. 24  For commentary on the Acheulian artefacts from the Bab

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Figure 4.5. Aerial views showing the landscape setting of Chalcolithic sites Dahara El Beida and Iraq El Bir on the watershed between the Jarash and Majarr–Tannur valleys. (a) Oblique aerial 3-D view along the watershed, looking south, showing the Chalcolithic sites (black arrows) in the context of soil areas (white arrows) occupying depressions along the watershed; (b) View of the same area looking east. Adapted from Oxford, EAMENA, Jordan Valley Survey, 45B Squadron, Frame 10578, 1930. Courtesy of EAMENA.

The important Tell Abu Suwwan Neolithic settlement was established in the early PPNB on natural terraces at Bab Amman overlooking the important ancient sources of Ficus Springs, and there is evidence of site occupation spanning four millennia.25 One of only a handful of Neolithic sites excavated in Jordan north of the Zarqa River, it has been estimated that this ‘megasite’ sup-

Amman-Tell Abu Suwwan locality, see Kirkbride 1958, 9–11 and Zeuner 1957, 23. 25   Al-Nahar 2010, 2013b; 2018. For a recent overview of Neolithic research in Jordan, see Rollefson 2019a.

ported a population of up to two thousand.26 Flint lithics recorded by JHS point to a broader Epipalaeolithic– PPN presence between Tell Abu Suwwan and Birketein and, further afield, PPNB flint lithics have been identified at Khirbet Ain Riyashi in the Majarr–Tannur valley adjacent to Riyashi spring.27 The Neolithic sites were located in close proximity to very strong springs, but it is not known how these water 26 

Rollefson 2020, 131, table 1. For a description of JHS flint lithic sites, see Amman, MS Jarash Hinterland Survey 2010 Preliminary Report, 34–44. For the Khirbet Ain Riyashi PPNB site, see Hanbury-Tenison 1987, 154. 27 

Historical Contexts supplies were managed. Runoff-harvesting opportunities abound in the study area and, given the location of Neolithic sites adjacent to exposed bedrock, some form of runoff management would have been unavoidable in the wet season; however, no attested evidence of local management practices from this period has yet emerged. The location of Tell Abu Suwwan on terraces below the substantial Bab Amman mesa runoff-field east of the later Hippodrome is particularly suggestive, especially as there is evidence of runoff-harvesting into a large bedrock cistern on the slope above the Neolithic settlement; however, the cistern is undated (see Chapter 7).28 The sources at Ficus Springs no longer flow but are likely to have influenced the location of Tell Abu Suwwan. The water from these springs and from the wadi’s perennial flow could have been utilized with little effort to irrigate the valley floor downstream and for domestic use. The better water security afforded Tell Abu Suwwan by the availability of runoff and spring sources could partially explain the site’s lengthy occupation span compared to other Neolithic megasites in the region.29 There is evidence of sparse occupation during the Chalcolithic/Proto-Urban period in the Jarash valley at Tell Jarash and Birketein and at opposite ends of the Wadi Majarr valley.30 The Chalcolithic sites of Dahara El Beida and Iraq El Bir were located on the ridge forming the watershed north-east of the city lie beside runoff-harvesting sites and soil-filled depressions along the watershed (Figs  4.5a–4.5b). 31 There are a number of spring sites on the western slopes within 400 m–750 m of the ridgetop, which means that the habitation sites lay much closer to water than previously thought.32 In contrast, the hilltop Chalcolithic site of Tell er-Riyashi at the head of Wadi Tannur lay within a few hundreds of metres of the Riyashi and Tannur perennial springs. Rainwater harvesting and water carried from the nearby 28  A short section of an undated water channel cut into bedrock found during the Tell Abu-Suwwan excavations may have carried runoff; see Al-Nahar 2006, 11. 29  See Rollefson 2020. 30  For Tell Jarash, see Glueck 1951, 60. The so-called ProtoUrban period, a term introduced by Kathleen Kenyon (1966), was placed between the Chalcolithic and Early Bronze Age periods. 31  See Kirkbride 1957, 15–18 site II; 18–20 site III; HanburyTenison 1987, 154 site 01; 155 site 20. 32  Hanbury-Tenison 1987. There are inconsistencies in the site locations provided by Kirkbride (1958) and Hanbury-Tenison (1987): Kirkbride stated that the sites were half a mile apart, but Hanbury-Tenison’s plan coordinates place them 0.93 miles (1500 m) apart.

97 springs would have satisfied the domestic needs of the Tell er-Riyashi settlement, and it is likely that cultivation took place close along the valley floor downstream of the springs. Bronze Age Human occupation became more extensive in EBI.33 The Chalcolithic site at Tell Jarash continued to be occupied, and additional settlements were established in the Jarash valley near major springs. In the Majarr–Tannur valley, there is a marked concentration of settlements on hills around the permanent Riyashi and Tannur springs, and, once again, rainwater harvesting and water carried from the nearby springs would have satisfied the needs of the hilltop settlement areas. The many primitive rock-cut press installations noted in the settlement areas during the study are testament to the orchard crops grown, and an increase in demand for irrigation water can be inferred from these installations. Evidence of water management in the valley bottoms downstream of the springs has not survived, but it is assumed that gardens were cultivated as they are today. Elsewhere, cultivation would have been rain-fed. The number of settlements declined in EBII and III. Virtually all occupation sites in the Majarr–Tannur valley were abandoned, and occupation in the Jarash valley was limited to sites at Birketein, Tell Jarash, and Khirbet Khaled in the central valley. These locations were likely chosen to take advantage of the availability of defendable sites with ready access to good soils and strong springs. Khirbet Khaled, 1.5 km south of Jarash, was the largest site in EBII and was particularly well placed with regard to spring sources. The strong sources at Ficus Springs lay in the Jarash valley 0.5 km north of the tell, and it is quite possible that some of the many rock-cut water installations and aqueducts at Ficus Springs date to the Early Bronze Age or even earlier. In the Middle Bronze Age, occupation moved across Wadi Jarash from Tell Jarash site to two smaller locations; an eastern hillock (Camp Hill) and a western promontory (Zeus Hill) 200 m to the south-west that became a cult site and was later the site of the Zeus Sanctuary.34 The reasons for this move are unclear, but both sites were dwarfed by the Khirbet Khaled settlement to the south. Prior to the study, it was thought that evidence of Late Bronze Age occupation 33  For a plan showing the distribution of EBI sites in the study area, see Boyer 2018a, fig. 5b. 34  Braemer 1989, 318.

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98 was restricted to Camp Hill and the Zeus Sanctuary, but this view is now challenged by a Late Bronze Age date obtained from charcoal in concrete foundations beneath the eastern wall of the Roman–Byzantine Birketein bathhouse.35 Iron Age Occupation around Camp Hill–Zeus Hill expanded in the Late Bronze Age–Iron Age  I period to include an area between the Oval Piazza and the North Gate.36 Ceramic evidence on the east bank of Wadi Jarash testifies to activities on the eastern lower terrace in the Iron Age,37 and Kehrberg identified Iron Age tombs on the slopes above this terrace.38 The site of modern Jarash became the largest Iron Age settlement in the Jarash valley.39 A cultic site was established in a grotto on Zeus Hill and was in use in the seventh or sixth century bc.40 Sites were also occupied close to the Tannur and Riyashi springs and at El-Hute in the Majarr–Tannur valley, and some fortified/defensive sites were established on hilltops close to the northern and eastern boundaries of the study area. No proof of Iron Age water management in the study area has yet been identified. Hellenistic Period (332 bc to 64 bc) The date of the first Hellenistic settlement and the continuity of settlement in the Hellenistic period is uncertain.41 There is numismatic and literary evidence from the Roman and Byzantine periods respectively of a tradition that a colony of veterans was founded by Alexander the Great, or General Perdiccas.42 This, however, appears to be contradicted by the available archaeo­

35  Sample B-480984, see Appendix D. For a recently published Late Bronze Age radio­carbon date from the Zeus ‘Haut Lieu’, see Seigne 2019a, 62. 36  Barghouti 1982, 221–26; Kehrberg 2011, fig. 4.1. For a plan showing the distribution of Iron Age I sites in the study area, see Boyer 2018a, fig. 6a. 37  Braemer 1989, 318; 1992, 198; Mittmann 1970, 98. 38  Kehrberg 2011, fig. 4.1. 39  This site may have been given the Semitic name grš referred to by Graf (1992, 11). 40  Seigne 1997b, 995. 41  For commentaries on the evidence, see Raja 2012, 144–50; Seigne 2019a; Lichtenberger and Raja 2020, 7–8. 42  Cohen 2006, 248.

logical evidence. 43 Indirect evidence of a Seleucid foundation comes from two sources; firstly, the settlement’s Hellenistic name, Antioch on the Chrysorrhoas, which has been taken to imply a foundation by Anti­ ochus  IV (175–164  bc); secondly, the occurrence of typical Macedonian names in several early inscriptions.44 Control of Gerasa passed from the Seleucids to Theodorus of Philadelphia in the late second century bc, and then to the Jewish king Alexander Jannaeus in the early first century bc.45 There is a gap in the occupational record of the city area between the eighth century bc and the second century bc,46 although the evidence of cultic use of the Zeus Hill site in the seventh or sixth century bc posited by Seigne narrows this gap.47 Archaeo­logical and other evidence from the Hellenistic period is summarized in Table 4.1, and the location of sites is presented in Figure 4.6. The main problem with understanding the nature of occupation in the Hellenistic period is the scarcity of evidence from firmly dated archaeo­logical contexts, the second-century bc rock-cut burial found beneath the northern city wall in ‘trench 100’ being a rare example.48 The preponderance of circumstantial evidence of Hellenistic occupation has fuelled debate on the location and permanence of occupation in the city area. Rubina Raja summed up the problem: no evidence confirming domestic housing in this period has come to light. The late Hellenistic finds offer no certain proof of continuous occupation in the last two centuries bc and the scanty evidence indicates that an actual town plan did not exist in the late Hellenistic period.49

Initially, the scant evidence suggested that Hellenistic activities were nucleated in the Camp Hill–Zeus Hill area and covered perhaps 4–5 ha, with necropoleis and possible satellite occupational sites and industrial areas 43 

Braemer 1989, 318. Gatier 1993, 19–20 cited by Coleman 2013, 155. The very existence of a Hellenic foundation has been challenged; see Raja 2012. 45  Kraeling 1938a, 33. 46  Braemer 1989, 318. This situation is mirrored at Pella; see Tidmarsh 2001, 191. 47  Seigne 2000, 91. 48  Kehrberg and Manley 2002; Kehrberg-Ostraz and Manley 2019. 49  Raja 2012, 246. Raja challenged all the evidence, stating ‘the only certain archaeo­logical evidence being a Hellenistic architectural phase, the so-called naos, in the lower temenos of the Sanctuary of Zeus’ (p. 148). 44 

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Figure 4.6. Map showing the location of Hellenistic (second–first centuries bc) archaeo­logical sites in the city area, mentioned in the text. Adapted from Stott, Raja, and Lichtenberger 2019.

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100 Table 4.1. Summary of archaeo­logical (excavation) evidence from the Hellenistic period in Jarash. Location

Evidence

Reference

Camp Hill

Pits and ceramics

Braemer 1989, 318.

Cardo area

Early gate and roadway (‘proto Cardo’)

Seigne 1992, 335.

Cathedral

Temple

Brenk 2015, 412; Jäggi, Meier, and Brenk 1998, 426.

Hippodrome

Necropolis — Late Hellenistic

Kehrberg 2011, fig. 4.

Hippodrome area

Mausoleum — Late Hellenistic

Seigne and Morin 1995.

North-West Quarter

Ceramics and glass

Lichtenberger and Raja 2015, 486.

North city wall

Tomb — Late Hellenistic

Kehrberg 2002.

North Gate

Coins

Shiyyab and Bauzou 2021, 189.

Oval Piazza area

Rhodian jar handles

Welles 1938, 460, nos 241–42.

Oval Piazza, Cardo, South Decumanus

Walls and streets

Barghouti 1982, 218–28.

South Decumanus, rooms 29 and 22

Hellenistic lamps and other deposits

Gawlikowski 1986, 109.

Southern tabernae on Cardo, Artemision

Ceramics and coins

Parapetti 1989, 5–10; Brizzi 2018, 102.

South Theatre area

Large pottery site

Kehrberg and Manley 2003b.

South-West Quarter

Diagonal streets

Blanke 2017, 7–9; 2018b, 49.

Zeus Hill

Necropolis/ temple site / inscription

Gatier and Seigne 2006.

Zeus Sanctuary

Hellenistic naos

Enzel and others 2003.

located outside this area. Excavations by Barghouti revealed walls and streets of Hellenistic date, but his interpretation was challenged by Pierobon, who was writing before the results of excavations in the Camp Hill area in the mid–late 1980s by Braemer were published.50 Braemer’s work confirmed Hellenistic occupation in this area, but not its purpose or extent. Table 4.1 shows that new discoveries of Hellenistic activity were made at various locations between the Hippodrome and the North gate over the ensuing decades, but perhaps the most intriguing evidence to emerge recently is the recognition of a network of diagonal streets in the South-West Quarter that predates the Roman north– south orthogonal network and may be Hellenistic.51 The extent of the Hellenistic settlement remains uncertain, but the presence of the diagonal streets, taken together with the other evidence from further north, especially in the vicinity of the southern tabernae on the Cardo, suggests that Hellenistic settlement was contained within a perimeter of up to 20 ha in the South-West Quarter.52 50 

Pierobon 1983–1984, 31. Blanke 2017, 7–9. 52   See Brizzi 2018, 102 n.  60. Kehrberg (2004, 193–94) considered that the archaeo­logical evidence pointed to a ‘fairsized and developed township already by the end of the second or beginning of the first-century bc’ and that the first-century commentary by Flavius Josephus suggested that ‘Gerasa was a vibrant town of some standing already in the second century bc’. Graf (1992, 51 

Very little evidence of water management in the Hellenistic period has come to light. The earliest 14C AMS date from an aqueduct ( JW01) that approached the city area from the north-west shows that the aqueduct may have been in use in the first century bc, which is not inconsistent with the notion of a permanent settlement in the city area prior to the Roman conquest.53 The flow in this aqueduct in the Hellenistic period may have been only a fraction of the substantial flow from it in the Roman period (see discussion in Chapter 6). Waterrelated installations dating to the Hellenistic period are few in number, and no evidence has yet emerged of the existence of major water-consuming installations such as bathhouses or fountains from this period, so perhaps the major use of the water from the north-west aqueduct was agricultural? The presumably modest domestic requirements of the Hellenistic settlement in the city area would likely have been met from runoff and local spring sources. In the hinterland, evidence from regional surveys points to Hellenistic settlement of five sites close to the wadi within the Jarash valley and two sites in the Majarr–Tannur valley, but none have been 30) on the other hand, considered that Gerasa was ‘merely a simple fortified agricultural village’. 53  Table D1 in Appendix D lists radio­carbon dates obtained during the study.

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excavated.54 The possibility that water from Qwndeit spring south of the city may have been used for irrigation in the Late Hellenistic period is discussed in the entry for aqueduct JW05 in Appendix G. Nabataean Period (300 bc to ad 106) The possibility that a Nabataean settlement or colony existed in the city area has been much debated.55 The matter is of interest in the context of the present study as the existence of such a settlement raises the possibility of Nabataean influence in the design and implementation of the water management system. At its height in the first century bc, the Nabataean kingdom’s western boundary lay close to Gerasa (Fig. 4.7). Negev and Kropp claimed that reference to ‘GRŠW ’ or ‘Garsu’ in a Nabataean inscription in Petra referred to Gerasa ( Jarash), but Tholbecq recently suggested that GRŠW refers to the town of Gerasa in the Negev.56 Some level of Figure 4.7. Map of the northern boundary of the Nabataean kingdom around 85 bc, based Nabataean presence in Jarash is attested on data from Ababsa 2013, fig. III.6. Adapted from [accessed 1 December 2021]. on Camp Hill and Nabataean architectural fragments from an unknown building, plus a small number of coins.57 Although Wenning evidence of any Nabataean water management infraconsidered that Gerasa had some significance to the structure that can be attributed to it. Nabataeans as a religious centre, there is no evidence of a separate Nabataean settlement, and the balance of Roman Period (64 bc to ad 324) present evidence suggests that the Nabataean presence The locations of Roman-period settlements identiin Gerasa was small and probably related to trading.58 If fied from regional surveys are shown in Figure 4.8. a Nabataean colony existed, there is currently no direct Gerasa came under Roman control around 63 bc and was placed in the newly created province of Syria by 54  For a plan showing the distribution of Hellenistic sites in the Pompey. There is little published archaeo­logical evistudy area, see Boyer 2018a, fig. 6b. 55  See Kraeling 1938a, 27–28; Kraeling 1941, 7–14; Wenning dence that relates to the first century of Roman rule, 1992, 88–90. and none at all from the eastern side of the city. Epi­ 56  See Negev 1978, 613; Kropp 2013, 217; Tholbecq 2019. graphic evidence attests to the existence of a govern57  Depending on the reading, the inscription honours either ing council (boulé) issuing decrees by ad  10, which the erection of a statue to two Nabataean kings, possibly Aretas IV shows that a permanent settlement was in place by and Rabbel  II dated to ad  91 (Welles 1938, 371, no.  1), or the the turn of the first century. 59 The first-century bc delimitation of a sacred area dated to ad 81 (Bowersock 1973, 139). necropoleis south of the city continued to be used For details of the Nabataean architectural fragments, see Wenning 1992, 89. For a recent discovery of coins near the North Gate, see Shiyyab and Bauzou 2021, 186. 58  Wenning 1994, 35.

59 

Gatier 2002, 278.

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after the Early Roman period evident in Figure  4.8 indicates that this increased activity and prosperity extended to the countryside. The boundaries of the settlement in the first century have yet to be defined, but the evidence from the North-West Quarter raises the possibility that there were several separate residential zones in the city area. Seigne proposed a nucleated settlement centred on Camp Hill; however, Brizzi noted evidence of a linear occupation zone between the later Cardo and Wadi Jarash, extending from the vicinity of Museum Hill to the location of the later West Propylaeum.63 By the end of the first century, the South Theatre and West Baths were constructed at opposite ends of this occupation zone, linked by the early Cardo, and the water installations in these two monuments added to the domestic demand for water. 64 Temples were located on Figure 4.8. Map of sites identified as ‘Early Roman’ or ‘Roman’ from published regional surveys. Zeus Hill and beneath the later Satellite base map data, Google © 2016 CNES/Astrium; © 2016 DigitalGlobe. Cathedral, and the pre-Antonine Artemis Temple was probably 60 located in the vicinity of the Artemis lower terrace.65 until the early second century. Occupation of Camp The pace of construction in the city accelerated in Hill continued, and additions and alterations were the early second century. Gerasa’s transfer to Provincia made to the lower terrace on Zeus Hill in the early Arabia in ad 106 heralded an unprecedented rise in the first century. 61 A substantial building was built over city’s fortune. The city’s elevated position in the province a large basin or cistern on the hilltop in the city’s is attested by abundant epi­graphic evidence that implies North-West Quarter in the first half of the century, it was the headquarters of the province’s financial procuand other excavation evidence obtained by JNWQ rator from Hadrian’s visit in ad 130 to Diocletian’s reign indicates substantial activity in this quarter in the in ad 286.66 The greater part of the impressive secondfirst century. 62 century public building programme was carried out in The mid- to late first century marked a turning point in Gerasa’s progress, with the evidence from excavations 63  See Seigne 1992; Brizzi 2018, 102 n. 60. and inscriptions indicating the establishment of a new urban street plan and the construction of some public 64  Seigne (2019) considers that the early Cardo and Oval Piazza buildings on the west bank (Table 4.2). The increase in the likely date to ad 110–120, with the partial widening of the Cardo occurring c. ad 150. number of settlements close to wadis and major springs 65 

60 

Kehrberg 2011, 3. For details of excavations around Camp Hill, see Braemer 1989, 318. For details of excavations on Zeus Hill, see Seigne 1997b, 998. 62  For the dating of the cistern beneath the large building, see Philippsen and Olsen 2020, 197–98. 61 

Brizzi 2018, 102–03. See especially Haensch 1997, 244; also Cotton and Eck 2005, 30; Gatier 1996; Haensch 1993; Kennedy 2007, 162. Eight procurators are named in inscriptions according to Welles (1938, 592; also, Welles 1938, 435, nos 171–72; 436–37, nos 174–79; 449, no. 207), and Gatier (1996) provides information on a further seven inscriptions. 66  

Historical Contexts

103

Table 4.2. Main public buildings constructed in Gerasa ad 50–100. Type of Description Construction

New Urban Street Plan

Buildings

Infilling of wadi between Camp Hill and the Zeus Sanctuary and construction of the Oval Piazza.

Fisher 1932, 7.

Laying out and paving of Cardo linking the north end of the Oval Piazza and the North Gate.

Kraeling 1938, 42–43; Ball and others 1986, 392.

The west side of the North Decumanus was laid out but not paved.

Ball and others 1986, 392.

Ionic colonnade added to the Cardo

Ball and others 1986, 392.

An early Artemis Temple.

Welles 1938, 388–90, nos 27–29.

South Theatre (consecrated ad 90).

Sear and Hutson 2001, 107.

Temple on the site of the later Placcus Baths.

Fisher 1932, 16.

Early house on site of later so-called Cathedral.

Brenk, Jäggi, and Meier 1995, 220.

North-West Gate (dated by inscription to ad 75/76).

Welles 1938, 397–98, no. 50.

the second half of the second century during the financial procurator’s presumed residency, and it has been suggested that the financial procurator’s residency may have triggered the building ‘boom’.67 There is evidence from the western, northern, and eastern sectors of the city that at least part of the city wall dates to the second century, but the completion date of the whole wall is not yet settled.68 Such a large construction venture probably took place over decades, especially given the number of other public buildings under construction in the second century and the competition for human and material resources. The abundant use of spolia is evidence of later repairs necessary to remedy earthquake damage. Many of the prominent water installations in the city are dated to the second century, creating a surge in water demand. On the west bank, public fountains 67 

Lichtenberger and Raja 2018a, 147. For the most comprehensive study of the city walls and the dating of the various construction phases, see Kehrberg-Ostrasz and Manley 2019. Kehrberg-Ostrasz and Manley maintain that the wall construction dates to the early second century (chapter 2, 20). Seigne (1986a, 47–59), however, considers that wall construction dates to the late third/early fourth century. Lichtenberger and Raja (2015, 485 n.  8) noted ‘All necropoleis of the second and third centuries c.e. are located outside the course of the city walls’. Recent excavations of the city wall in the city’s North-West Quarter provide additional support for a likely mid-second-century date for the wall foundations on the western side of the city; see Lichtenberger and Raja 2019c; 2019f, 66; 2020, 35–36. The completion of the northern section of the wall presumably post-dates the construction of the North Gate, dedicated in ad 115, as the gate was originally a freestanding structure unconnected to the city wall; for the dedication, see Welles 1938, 401, nos 56 and 57. 68 

Reference

were established along the Cardo and on the North Tetrapylon in the second half of the second century, and the Nymphaeum was completed by ad 190/91.69 On the east bank, the monumentalization of Qairawan spring has been attributed to the second century, and the first phase of the Large East Baths has been attributed to the mid-second century.70 The South Bridge and North Bridge were probably built around the same time.71 The masonry reservoir at Birketein, north of the city, was probably constructed by the end of the second century (see Chapter 6).72 The major public building projects had been completed by the beginning of the third century. Known public constructions in the third century are limited to 69   For the Cardo fountains, see Seigne 2008, 49. For the fountains on the North Tetrapylon, see Seigne 2008, 37. 70  For the dating of the monumental walls at Qairawan spring, see Seigne 2004, 175. For the dating of the construction of the Large East Baths, see Friedland 2003, 413; Lepaon 2012b, 198. An inscription on a large statue from the baths excavated in 2016 is dated to ad 154 (Weber-Karyotakis and Gatier 2018). 71  A third bridge might be expected at the point where the North Decumanus meets the wadi beside the West Baths, and there is evidence of a ruined arched bridge at this location in GuillaumeRey’s photo­g raphic panorama of the west bank taken in 1858 (Rey 1861, pl.  XX). Schumacher thought that there were up to five bridges: ‘There were 4 bridges over the creek: one each at the northern inflow and southern outflow of the creek served to pass over the city wall, two others were road bridges in the centre of the city. Possibly, although the foundation walls are missing now, a third road bridge at the Chān [West Baths] led over the brook’ (1902, 124; English translation by the author). 72  A terminus ante quem for the reservoir’s construction is provided by the portico/colonnade around the reservoir that is dated by an inscription to ad 209–211 (Welles 1938, 428, no. 153).

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Figure 4.9. A modern aerial view of the site of Der Abu Saedi in the southern Jarash valley, looking north. Adapted from APAAME_20130428_DDB-1013, photo­grapher D. Boyer, courtesy of APAAME.

additions and improvements to existing buildings and installations. On the west side of the city, ‘fountain A’ was constructed on the Cardo,73 fountains were constructed at the entrance to the Odeum,74 and the first phase of the Central Baths was completed,75 while on the east side of the city, the second phase of the Large East Baths may date to this period.76 Archaeo­logical information on Roman-period urban housing is scant, and it is, therefore, difficult to estimate the increase in domestic water demand in this period. Seigne 2008, 39. Seigne 2008. 75  Blanke, Lorien, and Rattenborg 2010, 312. 76  Friedland (2003, 413) dates the second phase to the third century, while Lepaon, Turshan, and Weber-Karyotakis (2018, 133) considered that the second phase of the so-called northern hall dates to ‘the turn of the second and the third centuries at the earliest’.

The Roman occupation levels were largely removed during later building construction phases, and this, together with an archaeo­logical focus on the major Roman monuments, means that knowledge of domestic housing has advanced little in the last ninety years. Gawlikowski was able to provide rare evidence of extended domestic use of a site from the Early Roman period until the Abbasid period,77 but the most detailed occupational evidence in recent studies comes from the city’s North-West Quarter. Here, the JNWQ team argue that the archaeo­logical finds indicate that ‘extensive building activity did not start until the Late Roman period’, which contrasts with the radio­carbon dating evidence that implies a strong presence in the period ad 130–230 that declines thereafter.78 The onset of this apparent decline is discussed in Part 3 in the context of the failure of an important north-west aqueduct and the infilling of the large cistern at the top of the hill in the North-West Quarter. Much less is known of activities in the South-West Quarter in the Roman period, but the provision of a new aqueduct below the threshold of the South-West Gate around the mid-third–early fourth centuries suggests either an increase in water demand or perhaps the replacement of a previous supply from another source. The relative abundance of archaeo­logical evidence of urban activity contrasts sharply with the scarcity of evidence of rural activities. Known extramural Romanperiod sites in the Jarash valley are scattered in rather narrow corridors that generally follow the course of Wadi ed Deir–Wadi Jarash and the Roman roads to Adra’a, Philadelphia, and Pella. The sites include agropastoral hamlets, bathhouses, and military posts, and several sites probably had more than one function. 79 The presence of wine and oil press installations in the area indicates that agricultural activities included orchard crop cultivation. The paucity of recorded occupation sites from the Roman period in the rich agricultural soil with good water sources adjacent to the city is anomalous when compared to the far greater number of such sites recorded in the Byzantine period. A number of ancient but undated sites recorded in the area by Schumacher may, in fact, be Roman, and this, coupled with the possibility that the Roman sites may also

73  74 

77 

Gawlikowski 1986. Philippsen and Olsen 2020, 194–96. 79  An example is Deir el Liyat, which lay on the Roman road to Pella via Suf, but also lay close to rich farmland, including an irrigated area of c. 20 ha on a south-facing slope at chirbet dahabōn to the south-west. 78 

Historical Contexts have been mainly small farmsteads with a small footprint that did not survive subsequent occupations, may explain the discrepancy.80 The majority recorded in surveys of the Majarr–Tannur valley were hamlet- or villasized sites that were presumably based on agro-pastoral activities, although Sapin posited that the Makhbata (Mehbethah) site 500 m south of Tannur spring was a craft (metallurgical?) site with a shrine possibly dedicated to Haddad. 81 In the Jarash valley, small Roman occupation sites are found on hilltops on the east bank of Wadi Jarash south of the city and scattered beside Wadi Suf, the largest perhaps being at Suf.  While located near rich soil and water supplies, the nature of the buildings is not clear from the available evidence, although presumably related to agricultural activities. Rock-cut canals supplied runoff or spring water to adjacent fields at Mesar Tokh 2 km south of Jarash, but the canals are undated. The author considers that one of the largest settlements in the Jarash valley in the Roman period may have been a site located c. 4 km south of the city that was identified during the present study from the stereo­ graphic interpretation of aerial photo­g raphs taken in 1953 (Fig.  4.9). 82 It lies immediately east of two Byzantine sites 0.5  km apart, referred to as dēr abu sa‘ēdi on the Gerasa–Philadelphia Roman road (henceforth, Der Abu Saedi).83 The aerial photo­g raphs show that the ruins of the c.  7  ha site were relatively well exposed in 1953, but the ruins are now almost totally obscured by a modern plant nursery. The site occupies a mid-slope terrace 80  m–110  m wide developed on sandstone bedrock located c. 50 m below the level of the Roman road and c. 30 m–40 m above the bed of Wadi Jarash (Fig. 4.10). An aqueduct sourced from springs to the north ran along the foot of the scarp that formed the western boundary of the site. Photo­graphic interpretation identified several large, well-constructed masonry buildings, a possible bathhouse, and several rock-cut installations using water supplied from the aqueduct. A  possible early watermill on the eastern edge of a terrace appears to have been supplied from the aqueduct already mentioned. While the function of the settlement is unclear, 80  The Schumacher sites include dēr ‘amud, mughr el-maghāzī, and chirbet dahabōn; see Steuernagel 1925, A274. 81  Sapin 1998, 129 n. 44. 82  The instrument used in the analysis was a Topcon MP-3 mir­ ror stereoscope. The photo­graphs are HAS-6–111 and 6–112. 83  Mittmann 1970, 107; Steuernagel 1925, A275.

105

Figure 4.10. Der Abu Saedi. Plan of archaeo­logical features interpreted from a stereoscopic study of aerial photo­graphs taken in 1953.

the size of the buildings and the existence of a possible bathhouse suggest either a settlement built by the local administration or perhaps a villa rustica owned by a member of the ruling class, although the use of the term ‘Der’ or ‘Dayr’ might suggest a monastery or convent. The date of the structures on the terrace is uncertain. The only in situ archaeo­logical features identified during field survey were water channels cut into bedrock and tufa from a water source covering a rock face near the site of the possible watermill, but dressed limestone blocks and concrete rubble were also found reused in modern field walls. The strongly built masonry buildings appear to be roughly similar in appearance to second-century structures within the city, but the only archaeo­logical dating evidence comes from the Mega-Jordan database, which

Chapter 4

106

Figure 4.11. Map of Byzantine site locations. Satellite base map data, Google © 2021 CNES/ Airbus; © 2021 Maxar Techno­logies.

records two adjacent sites at the southern end of the terraces; Akka (sites numbered 31930 and 31931), and Deir Abu Sa’ede (sites numbered 56540–45). Roman, Late Byzantine, and Islamic dates are listed under the Mega-Jordan record for the Deir Abu Sa’ede sites and are presumably based on ceramic evidence. These dates imply the use or reuse of the site over an extended period but do not shed any light on the site’s function. Byzantine Period (ad 324 to 640) Evidence from regional surveys points to an increase in the number of settlements throughout the Jarash valley and the lower Majarr–Tannur valley in the Byzantine period. The location of these settlements is shown in Figure 4.11. The information base is not detailed enough to accurately discriminate settlement size, but many were likely to be hamlet-size or smaller.84 84 

This figure is a slightly revised version of Boyer 2018a, fig. 7b.

Major new building works in the city contracted still further in the Early Byzantine period, being limited to the Small East Baths in the mid-fourth century and the Synagogue in the late fourth–early fifth centuries.85 Several restoration or refurbishment projects were carried out in the first half of the fifth century and may have been a response to damage caused by the ad 418 earthquake.86 Other restorations carried out in the second half of the fifth century in the Macellum and the Odeum are unlikely to be related to earthquake damage. 87 85   For the Small East Baths, see Lepaon 2008, 67. For the Synagogue, see Crowfoot 1938, 239. 86  These projects are attested by inscriptions; they include the restoration of the city walls, and probably also a gate, in ad 440/41 (Welles 1938, 467–68, no. 273; Di Segni 1999, 154), renovation of a tower from the foundations in ad 441 (Welles 1938, 467–68, no. 274; Di Segni 1999, 173), and the reconstruction of a portico in ad 447 near the South-West Gate (Welles 1938, 469, no. 275; Di Segni 1999, 173). 87  For the Macellum refurbishment, see Uscatescu and MartinBueno 2018, 227. For the fifth-century alterations to the Odeum, see

Historical Contexts

107

Table 4.3. List of Christian churches in Gerasa. Location

Name

Type

Intramural

Cathedral complex

Basilica

1

3

TPQ 404–435, TAQ 455

Prophets, Apostles, and Martyrs

Cruciform

1

3

464/65

St Theodore complex

Basilica

1

3

494/96

Procopius complex

Basilica

3

3

526/27

St George Church

Circular

1

-

529

St Cosmas and St Damian Church

Basilica

1

3

529–533

St John Church

Square

1

3

531

Synagogue Church

Basilica

1

3

530/31

St Peter and St Paul complex

Basilica

3

3

540

Bishop Isaiah Church

Basilica

3

3

558/59

Propylaea Church

Basilica

1

3

565

Mortuary Church

Basilica

1

1

Sixth century

Cross Church

Basilica

1

?3

Late sixth/early seventh

Genesius complex

Basilica

1

3

611

Artemis ‘Altar Plaza’ Church

Basilica

1

1

First half seventh century

Elias, Maria, and Soreg Church

Basilica

nd

?1

Early seventh century

Zeus–Lower Terrace Church

Basilica

nd

1

Second quarter sixth century

Bankes Church

Basilica

3

5

nd

South-East Quarter Church*

Basilica

1

?1

nd

Extramural

Apses

Aisles Date

Octagonal Church

Octagonal

1

-

nd

Bishop Marianos Church

Basilica

1

1

570

Cemetery Church

Basilica

1

nd

nd

Notes: TPQ = Terminus post quem; TAQ = Terminus ante quem; nd = no data; * After Braun and others 2001.

The fifth century saw a resurgence of new building constructions that was largely related to the Christianization of the city.88 This building was focused in the central city area, where the large 6000 m2 Cathedral–St Theodore– Placcus Baths ecclesiastical complex was established.89 The frenzy of ecclesiastical building activities reached a peak in the Late Byzantine period under Justinianic emperors and included the restoration of the Placcus Baths in ad 584. A list of Gerasene churches is given in Table 4.3. Clark and others 1986, 233. 88  For a recent synopsis of the Gerasene churches, see Boyer 2018e. See also Michel 2001; March 2009; MacDonald 2010. 89   For the Cathedral, St  Theodore’s Church, and related buildings, see Crowfoot 1938, 201–25. For the Placcus Baths, see Fisher 1938c, 265–69; Lepaon 2015. Jäggi, Meier, and Brenk (1998, 429) provided a terminus post quem of ad 404–435 for the Cathedral’s construction. The Cathedral had previously been dated to the mid-fourth century (Biebel 1938, 309; Crowfoot 1931a, 10).

Much more is known about domestic housing than in the preceding Roman period. A residential suburb of c. 4 ha dating to the Byzantine–Umayyad period lay east of the Cardo between Camp Hill and the North Bridge. Further west, Fisher recorded five Byzantine houses dating to the fourth–sixth centuries west of St Theodore’s Church,90 and Gawlikowski described a multi-phased Byzantine–early Islamic house bordering the South Decumanus.91 Further afield, excavations have revealed evidence of a Late Roman and Byzantine settlement in the North-West Quarter and Byzantine housing in the South-West Quarter.92 There were many modifications to the urban water distribution system in the Byzantine period that are 90 

Fisher 1938. Gawlikowski 1986. 92  For housing in the North-West Quarter, see Johnson and others 2018, 21. For housing in the South-West Quarter, see Blanke 2018b, 44–45. 91 

108 discussed in Chapter 10. There is very little direct evidence of new constructions related to the water network in this period, although a dedication from ad 533 refers to the restoration or construction of a canal or pool possibly associated with a bathhouse. 93 Overall water demand from major end-users declined over the Byzantine period, especially following the closure of the city’s two largest thermae, the West Baths and the Large East Baths. Umayyad Period (ad 640 to 750) The excavations of the Islamic Jarash Project have revealed no evidence of destruction following the Islamic conquest, which is consistent with the commentary by the Islamic historian Al-Baladhuri (died ad 898) that the town surrendered peaceably.94 Jarash was established as an administrative and urban centre in the Jund alUrdunn military district within the Islamic province of Bilad al-Sham after the conquest.95 It lay on the caravan route between Amman and Pella (Fihl) and prospered in the Early Islamic period.96 The Byzantine–Umayyad transition is blurred in the urban archaeo­logical record. Iconoclastic damage to floor mosaics demonstrates that the Christian traditions continued through the Umayyad period in several churches. New domestic buildings emerge beside the South Decumanus, and there is evidence of continued industrial activity in the central city area, especially potteries such as those operating in the Artemis upper terrace precinct and craft activities in the shops fronting the western ambulacrum along the Cardo north of the Western Propylaeum.97 There is also evidence of the establishment of shops in the vicinity of the South Tetrakionion plaza and a new congregational mosque built adjacent to this plaza on the site of the abandoned

93  The construction of the water installations by a military officer, Flavius Sergius, is unusual in the Gerasene context. Given that a military establishment (the Electi Justiniani) is known to be present in the North-West Quarter around the same date, it is possible that the water installations were also located in the North-West Quarter (see Haensch, Lichtenberger, and Raja 2016; Lichtenberger and Raja 2018a, 156–58). The only west bank bathhouses known to have been operating in ad 533 were the Central Baths and the Placcus Baths, the latter being under ecclesiastical control. 94  Walmsley 2003b, 17. 95  Walmsley 1987, 17. 96  Blanke and Walmsley 2010, 5. 97  For details of craft activities in the shops, see Baldoni 2019.

Chapter 4 Central Baths and of domestic activities in the city’s North-West Quarter.98 As noted in Chapter 3, the city was affected by the ad  659 earthquake, especially the precinct along the Cardo between the Macellum and the West Propylaeum, which resulted in permanent damage to buildings such as the Propylaea Church and presumably also the water infrastructure in the vicinity. The decommissioning of many of the Cardo fountains after the sixth century points to a lack of water availability, and it is assumed that, thereafter, urban domestic demand was increasingly met from runoff sources. The mid-eighth-century earthquakes caused further severe damage to the city, and areas such as the North-West Quarter were abandoned, but research has shown that occupation of the area around the South Tetrakionion plaza continued into the tenth century.99 It is difficult to interpret the evidence of rural settlements occupied in the Umayyad period for several reasons. Firstly, the information base relies in large measure on the surveys by Mittmann (1960s) and HanburyTenison (1980s), which covered only part of the study area; secondly, the identification of Umayyad sites relies on interpretation of surface sherd scatters at a time when the issues related to the difficulty in discriminating Byzantine and Umayyad wares were poorly understood. The residue of Byzantine wares after the mid-seventh century as a result of the transition of cultures blurs the ability to distinguish Byzantine and Umayyad sites on the basis of ceramic archaeo­logy alone.100 The handful of rural Umayyad sites identified from the published corpus are shown in Figure 4.12, where they can be seen in the context of sites identified as Byzantine and Mamluk.101 The apparent radical reduction in rural Umayyad sites compared to Byzantine sites is probably illusory for the reasons stated above, especially with respect to the Majarr–Tannur valley. However, the available Mamluk 98  For an overview of the Byzantine–Umayyad transition of the city centre, see Rattenborg and Blanke 2017. For the North-West Quarter, see Lichtenberger and others 2016. For details of excavated Umayyad housing in the North-West Quarter, see Lichtenberger and Raja 2019f. 99  See Rattenborg and Blanke 2017. 100  For recent discussions on these problems and a biblio­graphy on the topics, see the papers contained in Lichtenberger and Raja 2019. See also Rattenborg and Blanke 2017. 101   The Mamluk sites in Figure 4.8 are taken from Glueck (‘Medi­e val Arabic’; 1934a; 1934b; 1935; 1939a; 1939b; 1942; 1951), Mittmann (1970), Leonard (1986), and the Jarash Hinterland Survey (Kennedy and Baker 2009; Baker and Kennedy 2010).

Historical Contexts

109

Figure 4.12. Map of Byzantine, Umayyad, and Mamluk site locations. Satellite base map data, Google © 2021 CNES/ Airbus; © 2021 Maxar Techno­logies.

data suggests that there was a sharp reduction in rural occupation between the Byzantine and Mamluk periods, and the Ottoman tax records from ad 1562/63 and 1596/67 show that rural occupation was even further reduced by the early Ottoman period.102

Discussion The limited archaeo­logical evidence from the settled suburbs constrains our understanding of the location of the city’s ‘heart’ at any given point in its long settlement history; however, there is a body of evidence that indicates that parts of the city were populated and depopulated at various times during its history. Braemer and 102  For details of the ad 1562/63 records, see Peterson 2018. For details of villages from the ad 1596/97 Ottoman tax records, see Hütteroth and Abdulfattah 1977; Peterson 2018. For a plan showing the distribution of villages in the study area from the ad 1596/97 records, see Boyer 2018a, fig. 8b.

Seigne emphasized the strong evidence of the occupational history in the Zeus Temple–Camp Hill area that spans the Bronze Age through to the Byzantine period and beyond, which implied that the city’s subsequent growth expanded from this core area.103 Kehrberg put forward an alternative scenario that saw the simultaneous development of separate temple communities at opposite ends of the city;104 with a Zeus Temple community established around Camp Hill and another community or communities established around a group of temples at the northern end in the vicinity of what would later become the Artemis Sanctuary.105 The evidence from the northern end of the town of the 103  See Braemer 1985; 1987; 1989; 1992; Seigne 1984; 1985; 1986a; 1986b; 1987. 104  Kehrberg 2011, 6–7. 105  Kehrberg 2011, 6–7. Raja (2015a, 279) referred to epi­ graphic evidence of ‘over 100 different gods that were worshipped in Gerasa over time’.

Chapter 4

110 early establishment of various public buildings and the laying out of the North Decumanus, seventy-five to one hundred years before the South Decumanus, and the almost simultaneous monumentalization of the Zeus and Artemis Sanctuaries in the mid-second century fits with Kehrberg’s analysis rather than a gradual expansion of the settlement from the south.106 A focus at the northern end of the city continued with the establishment of the Odeum, dedicated in ad 165/66, and the construction of a basilica on the north side of the South Decumanus.107 Agusta-Boularot and Seigne considered that the Odeum, basilica, and a large adjacent space they speculated to be an agora, formed the city’s civic centre. 108 If correct, then the area ceased to be a civic centre by the early fifth century when the entrances to the shops and the basilica lining the North Decumanus were walled up. The Odeum/ theatre continued in use until the early sixth century, by which time the North Decumanus colonnade was being dismantled or robbed, and it is likely that the decline in the use of these buildings reflected the demise of the surrounding urban area.109 Recent archaeo­logical evidence from the North-West Quarter implies that the area was a sparsely populated semi-urban space in the Early Roman period containing much water infrastructure but was densely settled in the Late Roman–Umayyad period. The South-West Quarter may have experienced a similar occupational history, but the archaeo­logical evidence is currently too scant to form an opinion. The sparsity of archaeo­logical evidence from the city east of the wadi has resulted in this area typically being ignored in discussions on the city’s urban development.110 Seigne considered that the eastern side of the city was not settled before the beginning of the third 106   For

the establishment of buildings beside the North Decumanus, see Ball and others 1986, 392. 107   For a description of the Odeum, see Clark and others 1986, 229. For the basilica, see Agusta-Boularot and Seigne 2005. Agusta-Boularot and Seigne argued that the Odeum was a reuse of a pre-existing Bouleterion. The so-called basilica is referred to as the ‘Corinthian building’ by Ball and others (1986, 392), and was built after the North Decumanus colonnade. 108  An alternative view on the space adjacent to the basilica was presented by Ball and others (1986), who considered that this space was vacant as there was no entrance to it from the North Decumanus. 109  Ball and others 1986, 392. 110  Seigne 1992; 1997a.

century.111 It seems likely, however, that an area so well endowed with natural springs and an extensive adjacent terrace would have been settled well before the third century; perhaps with urban villas for local elites and more humble housing for those servicing the installations constructed around the springs and the Large East Baths in the mid-second century. The access to the Artemis Sanctuary via the North Bridge and East Propylaeum around the middle of the second century also implies that there was a population located on the east side of the river that would use it. The Byzantine–Umayyad transition is barely reflected in the archaeo­logical record, but the midseventh-century earthquake that followed resulted in modifications in the central city area. Urban life in some parts of the city also survived the devastation of the massive earthquakes of the mid-eighth century; however, its administrative, and presumably, its economic importance, declined during the Abbasid period. Although listed in ninth–tenth-century Arabic sources as a district capital,112 it was probably reduced to the size of a large village by the early tenth century.113 The likely small size of the pre-Roman settlement meant that the water demand in this period would have been modest, with domestic requirements likely met from cisterns and local springs. Urban water demand reached a peak in the Roman–Early Byzantine period, driven by the water requirements of the public baths and fountains and by the domestic requirements of the rising urban population, and declined progressively thereafter. The industrial and agricultural requirements in the same period may also have been substantial but are currently unquantifiable. The demand situation in the hinterland is less clear due to a lack of dating evidence, but would have been largely driven by irrigation requirements. The components of the overall hydraulic system are discussed in Part 2, and the urban network is described in Part 3.

111 

Seigne 1992, 332. Walmsley 2011, 142. 113  Walmsley 1992, 379. 112 

Part 2 The Hydraulic System

Chapter 5

Water Sources

Figure 5.1. Schematic hierarchical representation of water sources (potable sources in italics).

Table 5.1. Modern rainfall statistics for weather stations within and adjacent to the study area. Station

Record Period

Rainfall (mm) Annual*

Mean Daily†

Max. Daily Rainfall (mm)‡

Wet Season Duration (Days)‡

No. Rainy Days ‡

Mean

Max

Min.

Mean

Max.

Min.

Mean

Max.

Medwar

1950–2009

220.47

7.95

38.0

130.0

0

nd

48

0

155

220

Jarash

1942–2009

355.72

9.03

51.4

127.0

10

39

59

120

177

230

Kitta

1937–2009

543.35

15.40

76.2

140.0

10

35

59

118

171

215

Notes: *Al-Qaisi 2010, table 11.1; †Al-Houri, Al-Omari and Saleh 2014, table 4; ‡Al-Houri, Al-Omari and Saleh 2014; nd = not determined

Introduction This chapter looks at the water sources that supplied the water transport and storage installations that are described in Chapters 6 and 7, respectively. Water sources in the study area are divided into two main harvesting groups based on source type; those sourced from groundwater and those sourced from surface runoff (Fig. 5.1). All water sources in the study area are derived from the direct or indirect harvesting of rainfall. The present rainy season lies between October and April, and typically no rain falls in the remaining months. Modern weather records show significant interannual variation in annual rainfall, maximum daily rainfall, the number of rainy days, and the duration of the wet season (Table 5.1). Al-Houri, Al-Omari, and Saleh calculated that maximum daily rainfall of 47.4 mm had a two-year return period, and maximum daily rainfall of 63.7 mm had a five-year return period, thus showing the frequency of significant runoff events and local flooding in the present climatic regime.1 Closer analysis of Jarash station weather records found that precipitation falls in more frequent but less intense events may result in runoff; for example, hourly rainfall exceeded 4 mm/hr on twentyseven occasions between 1988 and 2016. 1 

Al-Houri, Al-Omari, and Saleh 2014, table 4 and table 6.

Palaeoclimatic proxy evidence obtained during the present study from the analysis of calcium carbonate sediment lining an aqueduct that supplied Gerasa in the second and third centuries confirmed that a climatic pattern broadly similar to today’s pattern of variable winter wet season rainfall existed in the first–second centuries.2

Surface Runoff A rainfall regime of higher intensity events leading to surface runoff will support rainfall harvesting systems wherever there are suitable surfaces for its collection and storage. In areas where groundwater sources are scarce or non-existent, rainfall harvesting is usually the only water source, and many such harvesting systems were identified throughout the study area. Surface runoff systems can be separated into two subgroups based on the permeability of the runoff surface. Impermeable Surface Runoff

Rooftop/Courtyard Rooftops are ideal catchments for the collection of clean potable rainwater runoff and the storage of this water in cisterns. Cisterns ranging in date from Roman to the 2 

See Passchier and others 2021. The calcium carbonate is described in Chapter 6.

Chapter 5

114 Early Islamic period have been found in domestic contexts in various parts of the city, and similar installations would also have been used in earlier periods.3 Lepaon identified stormwater pipes draining the roof areas of the West Baths and the Large East Baths, demonstrating that the roofs of civic buildings in the ancient city collected runoff.4 Some of the largest cisterns in the city are associated with civic buildings, temples, and churches. A far greater quantity of rainwater would have collected on the paved courtyards and streets in the ancient city, especially the terraces of the city’s main temples, but it does not appear to have been collected for storage. In the case of the Artemis Temple, for example, the runoff from the Antonine lower terrace was directed into the Cardo main drain via an elaborate network of conduits.5 Cisterns are discussed in more detail in Chapter 7.

Bedrock Runoff There are extensive tracts of exposed karst limestone on hilltops within the study area, and evidence of rainfall harvesting is commonly found in these areas. Today, as in the past, rain falling on these surfaces is directed into nearby cisterns and reservoirs via natural channels and artificial canals. When properly constructed and maintained, very little water is lost to ground infiltration in such systems, and clean, potable water can be harvested from even small rain showers. The study found evidence of larger-scale (but older) systems that supported runoff farming by the construction of diversion walls, canals, or ditches to direct water downslope onto fields, terraces, or storage installations. Permeable Surface Runoff (Overland Flow) A proportion of rainfall that falls on the land surface away from bedrock outcrops is lost to ground infiltration, the degree of infiltration being largely determined by rainfall intensity, slope, surface roughness, soil surface conditions, and the amount and nature of any vegetation cover. Soil surface conditions are influenced by soil type, texture, and compaction effects. Three types of natural overland flow are generally recognized; sheet flow and rill flow on homogeneous hill slopes without natural channelling and channel flow within channels, wadis, and swales.

Hillslope Runoff Flow on the uppermost part of slopes starts as sheet flow; however, continuing rainfall results in saturation of the near-surface soil profile and an increase in flow velocity, such that within a short distance (1 km2 and is probably the largest irrigation system in the study area supplied from a single source. Several ruined masonry structures lie on the slope below the spring, including a masonry canal for an oblique chute watermill and an adjacent structure that may have been the mill-house. A ruined penstock mill lies 200 m downstream of the spring on the east bank: this is probably the ruin of ‘tahunet et tannur’ described by Schumacher in a visit at the end of the nineteenth century and is presumably of early Ottoman date or older.47 There were very few strong springs on the eastern side of the Majarr–Tannur valley, but Ain Nabi, located in the upper part of Wadi Umm Qantarah, was an impor47 

Steuernagel 1925, 368.

tant source of irrigation water. It is the northernmost of a small group of strong springs supplied from Fuheis Formation/Hummar Formation aquifers that originally flowed in the Wadi Umm Qantarah valley, and at c. 750 m, is the highest in elevation. It remains an irrigation source today, although the flow is much diminished.

The Relationship between Water Availability and Settlement Location A comparison between spring locations and known settlement sites provides an opportunity to determine the impact of water availability on historical settlement distribution patterns. The study found that the average density or concentration of springs in the study area is around 3/km2, which means that all settlements will, on average, lie within 500 m of a spring. In light of this, the study looked at settlement locations in relation to the strong springs, using the strength of spring discharge as

Water Sources

129

Figure 5.13. Map showing the relationship between strong springs and Late Roman– Byzantine and Byzantine sites. Satellite base map data, Google © 2017 DigitalGlobe; © 2017 CNES/Astrium.

the measure of a spring’s significance, in addition to analysing the spatial relationship.48 The distribution of settlement sites in the context of the distribution of strong springs is shown for three periods (EBI–EBII, Hellenistic–Early Roman, and Late Roman–Byzantine) in Figures 5.11, 5.12, and 5.13, respectively. The data show a close association of EBI–EBII sites with strong springs in the Jarash valley, but this is less evident in the Majarr–Tannur valley. Hellenistic–Early Roman sites were also associated with strong springs close to valley floors. Settlement expansion away from the strong springs becomes evident in the Late Roman–Byzantine period: settlements in the Majarr–Tannur valley were still located close to the valley floor in the Late Roman–Byzantine period; however, settlements were also established close to strong springs on the upper slopes in the upper Jarash valley. 48 

The results are discussed in Boyer 2018a, 226–28, figs 5–8.

The absence of Roman and Byzantine settlements on the upper slopes in some areas despite the presence of many springs coincides with gaps in survey coverage noted in Chapter 4, and it is anticipated that future surveys in these areas will find evidence of Roman and Byzantine occupation (Colour Plate 5).

Discussion The study area was generously endowed with natural water sources of good quality in the study period. The generally moister climatic conditions indicated from regional palaeoclimate proxies in the Hellenistic–Roman period compared to today meant that water sources would likely have included perennial flow in the various wadis derived from surplus spring discharges and flows from rainfall-runoff. The extent of the perennial flow would have depended on the season, the location of the strong springs, and the extent to which the spring flows

Chapter 5

130

Colour Plate 5. Map showing the relationship of Late Roman–Byzantine and Byzantine sites and spring locations (dot size reflects relative discharge strength). Areas rich in springs, but with few settlement sites, are highlighted. Satellite base map data, Google © 2017 DigitalGlobe; © 2017 CNES/Astrium.

were diverted for use by the local inhabitants. Perennial flows would likely have been strongest downstream of the city and downstream of Tannur spring, as these are areas where flows from Kurnub springs would have combined with flows from strong karstic springs upstream. Ionides observed in the 1930s that irrigation offtakes in Wadi Jarash resulted in very little of the perennial flow in the wadi reaching the Zarqa River, and a similar situation is likely to have prevailed in the Roman and Byzantine periods when irrigation water use appears to have peaked.49 Perennial flow is likely to have been 49 

Ionides 1939, 154.

stronger in the Hellenistic period, before the construction of the large irrigation aqueduct networks in the main valleys in the ensuing Roman period, which is consistent with the Hellenistic name of the city ‘Antioch on the Chrysorrhoas’ (or golden river). Today, the perennial wadi flow is small and is limited to Wadi Jarash downstream of the city. While it is axiomatic that water availability is a factor in determining the location and density of human settlement, the available evidence shows a clear relationship between settlement locations and strong springs close to valley floors in the Hellenistic–Byzantine period, and this is most pronounced in the Majarr–Tannur valley.

Chapter 6

Water Transport

W

ater was transported as either natural overland flow or via artificial conduits. We know from prehistoric studies from Jawa in eastern Jordan that some Chalcolithic–Early Bronze Age societies adopted sophisticated runoff catchment and surface flow management practices that generated greater agricultural yields.1 These greater yields supported protourban populations in the prehistoric period and larger urban populations in subsequent periods. In the study area, the large areas of exposed bedrock and a winter rainfall regime of high-intensity rainfall events provide ideal opportunities for the application of runoff catchment and surface flow strategies, and many ancient and modern examples are visible in the present landscape. The information presented in Chapter 3 shows that strong springs were also an important water source in the study period. These springs provided a reasonably reliable and controllable supply of good quality water that was distributed to urban and rural users via networks of aqueducts that are described below.

Transportation by Natural Surface Flow Perennial streamflow in the wadis is negligible today as a result of declining spring flows and irrigation offtakes, while the natural overland flow is limited to winter season runoff. A similar regime is also likely to have existed in the past, although the wetter climatic periods would have resulted in greater winter runoff. What is not clear, however, is the extent to which the higher spring discharges were ‘absorbed’ by the extensive irrigation networks and structures that diverted surface runoff in Antiquity and Late Antiquity. The use of rainwater harvesting via runoff catchment to supply water for cisterns remains a common practice, and some of these cisterns have been in use since historical times. While cisterns are a welcome source of water for domestic use and for watering livestock, the potential for cisterns to contribute to irrigation is limited by the generally small scale of the runoff catchments supplying them. 1 

For Jawa, see Müller-Neuhof 2014.

The ability to divert and store water from wadi streams via canals, barrages, and reservoirs offers greater potential for agricultural application and is discussed below. Artificial Structures Employed to Control and Harness Hillslope Runoff Ancient societies in the Levant developed strategies to control overland water flow resulting from hillslope runoff in areas of strong relief. Such flows can remove topsoil, and societies responded — perhaps intuitively — by constructing terraces to restrict water flow and limit soil loss while increasing the amount of retained moisture in the soil profile. The application of these remedial strategies in the study area is discussed below. There is abundant evidence in the landscape of the widespread establishment of agricultural terracing. Terracing is still practised today, with modern forms often replacing or modifying earlier forms. No studies of terracing systems in the study area have been published to date, although there are published studies covering the Mediterranean region and sites in the southern Levant.2 It is, however, possible to make some general comments on the types of terracing employed and their distribution. The older, more degraded terraces can be difficult to identify in the modern landscape. Groups of terraces were sometimes joined by enclosure walls running down the slope, which are more resistant to degradation and are the only means of identifying historical terracing in some areas.3 Walled trackways are a feature in some terraced areas, especially near ridge tops. These would have permitted access to the terraced areas but would also have kept herds of foraging domesticated animals from the cultivated crops on the terraces. The terraces were generally constructed using dry-stone retaining walls and occur in three main forms: (i) as long, narrow, stepped terraces 2   For studies of terraces in the Mediterranean region, see Grove and Rackham 2001; Gibson 2015; Turner and others 2021. For studies in Wadi Faynan, see Newson and others 2007, 152–55; Smith and others 2011, 222. For studies west of the Jordan River, see Gibson and Lewis 2017. 3  See Sapin 1998, 114.

Chapter 6

132

Figure 6.1. Aerial photo­graph of the central Jarash valley from 1953 showing terracing on east-facing slopes between the southern plateau and the El-Hammar plain. Adapted from Stott and others 2018.

following contours and often influenced by natural layering in horizontal limestone formations; (ii) as braided terraces where the terraces were constructed zig-zag fashion with access at either end; and (iii) as cross-wadi terraces (also known as check-dams) built across wadis. Braided terraces cut with bulldozers with no stone retaining walls have become a feature in the modern landscape, especially in landslide-prone terrains. Many terraced areas lie above 800 m elevation where the absence of spring water for irrigation means that cultivation would have been rainfed, relying on seasonal rainfall falling directly on the terrace soils and on runoff from adjacent bare bedrock that generally separates the terraces. A better understanding of the distribution of ancient terracing in the study area can be obtained from a study of APs from the first half of the twentieth century, while information on terrace construction can be determined from in-field inspection and the analysis of modern lowlevel APs. The earlier APs show the widespread use of terracing in both the Jarash and Majarr–Tannur valleys. An example of a terraced area flanking the central plateau in the central Jarash valley is shown in Figure 6.1,

and details of the terrace types in this area are shown in Figure 6.2. Long, stepped terraces were extensively developed along contours on the steep slopes below the northern watershed of the Jarash valley and below the northern and eastern watershed of the Majarr–Tannur valley. Although partially obscured by pine plantations in the modern landscape, the early APs reveal narrow terraces — some merely ledges a few metres wide — developed on layered Cretaceous limestone. Government 1:10,000 scale plans dating to 1950 show vineyards established on the terraces on the slopes below the northern watersheds, which hints at possible similar use in Antiquity.4 Ancient west-facing terraces are preserved close to the eastern watershed of the Majarr–Tannur valley to the east of Ain Nabi, and examples are shown in Figure 6.3. Figure 6.4a shows a trackway adjacent to a walled terrace close to the ridge top at the same locality, and evidence of double walls demonstrates that the trackway was walled with enclosure walls separate from the terrace walls. 4 

Jordan 1950, Zarqa Basin sheets 27/88 and 35/82.

Water Transport

133

Figure 6.2. Detailed aerial view of the terracing shown in Figure 6.1 showing the different terracing types. Adapted from Stott and others 2018.

Ancient use of these terraces is assumed from the remote location, their obvious age and degraded condition, and the presence of rock-cut installations of unknown type in adjacent rock outcrops. Evidence of likely ancient terracing at the north-eastern corner of the Majarr–Tannur valley watershed to the north of the ancient settlement of El Hute can be seen on APs dating to 1930 (Fig. 6.4b), and the 1:10,000 scale government plans show that vines were still being cultivated on some of these terraces as recently as the mid-twentieth century.5 These terraces 5 

Jordan 1950, Zarqa Basin sheet 35/82.

lie close to settlements with evidence of Bronze Age and Iron Age dates, and rock-cut installations are visible in bedrock on the ridgetop to the east. The use of crosswadi terracing is also widespread, and a likely ancient example in a small tributary wadi in the Majarr valley 1.2 km south-west of Ain Nabi is shown in Figure 6.5. No attempt was made to accurately date terrace walls using radio­carbon or OSL dating methods during the study, and there are as yet no published dates for these structures in the study area. Researchers have tended to rely on indirect methods to date terraces, such as the proximity of ancient settlements or buildings, even

Chapter 6

134

Figure 6.3. Low-level oblique aerial photo­graph showing ancient terracing on an east-facing 30 per cent slope adjacent to the eastern watershed in the Majarr–Tannur valley to the east of Ain Nabi at an elevation of c. 900 m. The betterpreserved walled terraces are highlighted in white, and the inset shows details of a section of dry-stone retaining wall up to 1 m high. Adapted from APAAME_20101021_DDB-0292, photo­grapher D. Boyer, courtesy of APAAME.

though such methods are acknowledged to have a low level of reliability.6 Recent research by Gadot and others in the Judean Highlands (Mt Eitan) cautions against the assumption that terraced walls are of ancient date.7 Recent OSL dating of terraces in the hills around Jerusalem found that the earliest terraces date to the latter half of the first millennium bc and were followed by additional terrace building phases in the Late Roman and Late Byzantine–Early Islamic periods; however, it 6  7 

See Wilkinson 2003, 66. Gadot and others 2016.

remains to be seen if these important conclusions can be applied more broadly in the southern Levant.8 Channel Flow Structures

Barrages Barrages (dams) can be used to store water, divert water to other storage facilities or irrigation channels, and control the flow of water. There are no known examples of substantial barrages being constructed across wadis in the study area or, apparently, elsewhere within the 8 

Gadot and others 2018. See also Avni, Porat, and Avni 2013.

Water Transport

135

Figure 6.4. Examples of ancient terracing from the upper eastern slopes of the Majarr–Tannur valley. (a) A trackway adjacent to a walled terrace, showing details of the separate enclosure wall of the trackway to that of the adjacent terrace. The terrace is highlighted in white. Adapted from APAAME_20101021_ DDB-0290, photo­grapher D. Boyer, courtesy of APAAME. (b) Narrow, stepped contour terraces developed on bedded Ghudran Amman Formation limestone north of the ancient settlement of El Hute visible in 1930 aerial photo­graphs. The ruins of an ancient walled settlement of uncertain date are just visible on the watershed ridge above the terraces. Adapted from Oxford, EAMENA, Jordan Valley Survey, frame 10578, 1930, courtesy of EAMENA.

Figure 6.5. An example of an ancient cross-wadi terrace in a small tributary in the Wadi Majarr valley to the south-west of Ain Nabi. Adapted from APAAME_20170927_DDB0082, photo­grapher D. Boyer, courtesy of APAAME.

Chapter 6

136

While no constructed barrages have been confirmed in the Jarash valley, the local topo­g raphy makes Birketein an ideal location for such a barrage. This site is adjacent to strong springs at a point where the valley is constricted to a width of