Radiocarbon Dating New Zealand Prehistory Using Marine Shell 9781841711300, 9781407351773

Table of contents :
Front Cover
Copyright
TABLE OF CONTENTS
ABSTRACT
ACKNOWLEDGEMENTS
LIST OF FIGURES
LIST OF TABLES
CHAPTER 1. INTRODUCTION
CHAPTER 2. THE RADIOCARBON METHOD
CHAPTER 3. THE SAMPLE TYPE DILEMMA IN RADIOCARBON DATING NEW ZEALAND ARCHAEOLOGY
CHAPTER 4. RADIOCARBON DATING CHARCOAL AND MARINE SHELL: CONSIDERATIONS FOR USE
CHAPTER 5. RESERVOIR CORRECTIONS
CHAPTER 6. ARCHAEOLOGICAL EXCAVATIONS
CHAPTER 7. ANALYSIS OF RADIOCARBON AGES FROM EXCAVATED ARCHAEOLOGICAL SITES
CHAPTER 8. DISCUSSION AND CONCLUSIONS
BIBLIOGRAPHY
APPENDIX 1
APPENDIX 2

Citation preview

Radiocarbon Dating New Zealand Prehistory Using Marine Shell

Matthew Schmidt

BAR International Series 842 2000

Published in 2019 by BAR Publishing, Oxford BAR International Series 842 Radiocarbon Dating New Zealand Prehistory Using Marine Shell © Matthew Schmidt and the Publisher 2000 The author’s moral rights under the 1988 UK Copyright, Designs and Patents Act are hereby expressly asserted. All rights reserved. No part of this work may be copied, reproduced, stored, sold, distributed, scanned, saved in any form of digital format or transmitted in any form digitally, without the written permission of the Publisher. ISBN 9781841711300 paperback ISBN 9781407351773 e-book DOI https://doi.org/10.30861/9781841711300 A catalogue record for this book is available from the British Library This book is available at www.barpublishing.com BAR Publishing is the trading name of British Archaeological Reports (Oxford) Ltd. British Archaeological Reports was first incorporated in 1974 to publish the BAR Series, International and British. In 1992 Hadrian Books Ltd became part of the BAR group. This volume was originally published by John and Erica Hedges in conjunction with British Archaeological Reports (Oxford) Ltd / Hadrian Books Ltd, the Series principal publisher, in 2000. This present volume is published by BAR Publishing, 2019.

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CONTENTS A bs t rac t A cknow ledgemen t s

i i i

L is tO fF igu re s L i s tO fT ab les CHAPTER 1 :I NTRODUCT ION

i x 1

R e la t ive And A b so lu te : D a t ing N ew Z ea land P reh is to ry R ad ioca rbon D a t ing a nd t h eN ew Z ea land P reh is to r ic S equence

1 1

A ims o ft h is S t udy

4

CHAPTER 2 : THE RAD IOCARBON METHOD

7

I n t roduc t ion

7

P r inc ip les a nd A s sump t ion s

7

R ad ioca rbon D a t ing A tT he U n ive r s i ty O f Wa ika to L abo ra to ry S amp le P re t rea tmen t C ha rcoa l P re t rea tmen t Ma r ine S he l l P re t rea tmen t R ad ioca rbon D a t ing b yL iqu id S c in t i l la t ion C oun t ing o fB enzene

8 8 9 1 0 1 0

S t a t is t ica l A na ly s is A nd C a l ib ra t ion O fC onven t iona l R ad ioca rbon Age s( CRA)

1 2

CHAPTER 3 : THE SA MPLE TYPE D ILEM MA I N RAD IOCARBON DAT ING NE W Z EALAND ARCHAEOLOGY I n t roduc t ion

1 3 1 3

I nves t iga t ions A nd O p in ions O n S amp le C ho ice A nd R e l iab i l i ty I nR ad ioca rbon D a t ing N ew Z ea land A rchaeo logy : AH is to r ica l R ev iew 1 3 D i scuss ion A nd C onc lu s ions F ind ing aR e l iab le S amp le T ype f o rR ad ioca rbon D a t ing N ew Z ea land A r chaeo logy AS o lu t ion t ot h e S amp le T ype D i lemma CHAPTER 4 : RAD IOCARBON DAT ING CHARCOAL AND MAR INE S HELL : CONS IDERAT IONS FOR U SE

2 4 2 4 2 7

2 9

I n t roduc t ion

2 9

T he P rob lem O fI nbu i l tA ge

2 9

L if eway s A nd H ab i ta t sO fS he l lf ish C ons t ruc t ion o ft h e S he l l a nd C a rbon S ou rce s

3 1 3 1

H ab i ta t sO fS he l lf i sh U sed F o rR ad ioca rbon D a t ing N ew Z ea land A rchaeo log ica l S i te s B iva lves G a s t ropods

3 3 3 3 3 4

F ac to r sT ha tI nf luence T he R ad ioca rbon D a t ing O fS he l lf i sh T he ' Ha rd Wa te rE f f ec t ' a nd ` Upwe l l ing '

3 4 3 4

T he O rgan ic C a rbon ( OC ) E f f ec t : A l te ra t ions I n 51 3C L eve ls D iscus s ion A nd C onc lu s ions CHAPTER 5 : RESERVO IR CORRECT IONS

3 5 3 5 3 7

I n t roduc t ion

3 7

T he R e servo i rE f f ec tA nd R eservo ir C o r rec t ions

3 7

T he N ew Z ea land Ma r ine S he l l S tanda rd a nd C a l ib ra t ion o fN ew Z ea land A r chaeo log ica l S amp les 3 7 AN ew Ma r ine S he l l C a l ib ra t ion Me thod T he B ox D if f us ion a nd G loba l C a rbon Mode ls C a lcu la t ion o f AR R ev iew O f AR R e sea rch AR ev iew o f AR R e sea rch L i te ra tu re D iscus s ion A nd C onc lus ions CHAPTER 6 : ARCHAEOLOG ICAL EXCAVAT IONS

3 8 3 8 3 9 4 2 4 3 4 5 4 7

I n t roduc t ion

4 7

K okohu ia ( 006 /317 ) , O ponon i A rchaeo log ica l E xcava t ion a nd A na lys is E nv i ronmen ta l R econs t ruc t ion

4 7 4 7 5 0

A o tea A rchaeo log ica l E xcava t ions a nd A na lys is E nv ironmen ta l R econ s t ruc t ion

5 1 5 1 5 4

P onu i I s land A rchaeo log ica l E xcava t ions a nd A na ly s is

5 5 5 5

L iga rB ay A rchaeo log ica l E xcava t ions a nd A na lys is E nv ironmen ta l R econ s t ruc t ion

6 2 6 2 6 2

S awp i tP o in t( N26 /214 ) A rchaeo log ica l E xcava t ion a nd A na ly s is E nv i ronmen ta l R econs t ruc t ion

6 3 6 3 6 4

S umma ry

6 4

CHAPTER 7 : ANALYS IS OF RAD IOCARBON AGES F ROM EXCAVATED ARCHAEOLOG ICAL S ITES

6 5

I n t roduc t ion

6 5

A r chaeo log ica l S i tes W i th C ha rcoa l /Ma r ine S he l l C h rono log ica l A g reemen t K okohu ia ( 006 /317 ) A o tea P onu i I s land L iga rB ay Awa roa

6 5 6 5 7 1 7 2 7 6 7 8

A r chaeo log ica l S i te s W i th No C ha rcoa l / Ma r ine S he l l C h rono log ica l A g reemen t I nbu i l tA ge P o s tD epo s i t iona l D is tu rbance : H is to r ic a nd P reh is to r ic M ix ing o fN a tu ra l a nd C u l tu ra l Ma te r ia l S umma ry

8 0 8 0 8 2 8 2 8 6

D iscuss ion A nd C onc lus ions R ad ioca rbon D a t ing o f Ma r ine S he l l a nd C ha rcoa l C ompa r ison o f Ma r ine S he l l C a l ib ra t ion Me thods

8 6 8 6 8 6

CHAPTER 8 :D ISCUSS ION AND CONCLUS IONS

9 5

O verv iew

9 5

T he S amp le T ype D i lemma R ev is i ted " Ch ronome t r ic H yg iene " f o rN ew Z ea land A rchaeo log ica l R ad ioca rbon D a tes . R esu l t sa nd A na ly s is

9 7 9 8 9 8

T he C hrono logy o fK okohu ia , P onu i I s land ,A o tea , L iga rB ay a nd S awp i t P o in t

1 09

C onc lus ions

10

B IBL IOGRAPHY

11

A PPEND IX 1 :R ad ioca rbon d a t ing l a bo ra to r ie sc ur ren t ly u nder tak ing AR r e sea rch

19

A PPEND IX 2 :R ad ioca rbon a ges mea su red i nt h is d i s se r ta t ion

1 21

ABSTRACT T e s t ing t h e r e l iab i l i ty o f m a r ine s he l l f o r r ad ioca rbon d a t ing N ew Z ea land p r eh i s tory h a s l o ng b een o ve rdue . T hough p a s t s t ud ie s h ave c ompa red ma r ine s h e l l a nd c ha r coa l r a d ioca rbon d a te s f r om t h e s ame c on tex t t od e te rm ine t h e r e l iab i l i ty o fm a r ine s he l l , o f t en t h e c ha r coa l s amp le s w e re u n iden t if ied . T he se s t ud ie sw e re t h e ref o re i n va l id d ue t ot h er i sk o fi n bu i l ta ge i nt h ec ha r coa l s amp le s . T h i s d i s ser ta t ion i n ves t iga te s t h e r e l iab i l i ty o f m a r ine s he l l f o r r a d ioca rbon d a t ing N ew Z ea land p r eh i s to ry . P a i red c ha rcoa l a nd m a r ine s he l l r a d ioca rbon a ge s f r om a r chaeo log ica l s i t e s e xcava ted f o rt h i s s t udy a nd f r om a l ready d a ted a r chaeo log ica l c on tex t s , a r e c ompa r ed . I nt h is c ompa r ison , t wo i s sue s a r e c on s ide red . F i r s t , f a c to r s w h ich c an a f f ec t t h e r ad ioca rbon d a t ing o fm a r ine s he l l a nd c ha r coa l s amp le s . S e cond , t h e e f f ec t o fu s ing e i the r o ft wo m a r ine s h e l l c a l ib ra t ion m e thod s i nt h e c ompa r ison o f ma r ine s h e l la nd c ha r coa lr a d ioca rbon d a te s . T he u pwe l l ing a nd h a rdwa te r a f f ec t s ( c au s ing s he l l a ge s t o a ppea r t oo o ld ) , a nd t h e i n co rpo ra t ion o f o r gan ic c a rbon ( c au s ing s he l l a ges t o a ppea r t oo o l d o r t oo y oung , d epend ing o n t h e s ou r ce o f t h e o rgan ic s ) a r e i d en t if ied a s i mpo r tan t v a r iab le s i nd a t ing s he l l . I nt h e c a se o f c ha r coa l , i ti sf ound t h a t a l though t h e i d en t if ica t ion o fc ha rcoa l s amp le s t ot w ig s o f s hor t l ived s pec ie s h a s b een p ropo sed a s a s o lu t ion t oi n bu i l t a ge , t h i s m ay s t i l l b e ap rob lem f o rc ha rcoa l s amp le s . I n co r r ec t d a ta o n t h e a c tua l l i f e s p an o f an umbe r o ft r ees a nd s h rub s i d en t if ied a ss ho r t l ived , a nd d ecay r a te s o fv a r ious f l o ra l s pec ie s a f t e rd ea th may s t i l l i nf luence c ha rcoa ld a te s . Ac r i t ique o ft h e t wo me thod s a va i lab le f o r c a l ib ra t ing m a r ine s h e l l r a d ioca rbon a ge s i su nder taken t o e xam ine t h e e f f ec t o f e ach o n a ge c a l ib ra t ion , a nd i nt h e c ompa r i son o f m a r ine s he l l a nd c ha rcoa l r a d ioca rbon a ge s . T he f i r s tm e thod i n vo lve s t h e a pp l ica t ion o f af i xed r e servo i rc o r rec t ion ( c a l led R ) , t oa m a r ine s he l l r a d ioca rbon a ge b ef o re c a l ib ra t ion o n a n a tmo sphe r ic c a l ib ra t ion c u r ve . T he s e cond m e thod e mp loy s amode l led ma r ine c u rve a nd al o ca l r e se rvo i rv a lue AR , a nd i sb a sed o n ab ox d i f f u s ion mode l w h ich s imu la te s f l uc tua t ion s i nR ( t ) t h rough t ime . T he t wo m a in d i f f e rence s i d en t if ied b e tween e ach c a l ib ra t ion m e thod a r e : a ) af i xed R c o r rec t ion d oe s n o t t a ke i n to a ccoun t c hange s i nR ( t ) t h rough t ime w he rea s t h e mode l led m a r ine c urve d oe s , a nd b ) t h e mode l led m a r ine c ur ve p rov ide s mo re d ef ined c a l ib ra ted a ge r a nge s c ompa r ed t or e se rvo i rc o r rec ted c a l ib ra ted m a r ine s he l l d a te sd ue t ot h e s moo thne s s o ft h is c urve . P a i red c ha r coa l a nd ma r ine s h e l l r ad ioca rbon d a te s f r om 1 9 a r chaeo log ica l d epo s i t s e xcava ted i nt h i s s t udy a r e a na ly sed . O f t h e se 1 9 d epo s i t s , 1 4 p o s se s s c ha rcoa l a nd m a r ine s h e l l d a te s w h ich a r e i n c h rono log ica l a g reemen t a f t e r c a l ib ra t ion . T h is i sn o t d ependen t o n t h e ma r ine s h e l l c a l ib ra t ion m e thod u s ed . H oweve r ,t h e mode l led m a r ine c urve i sf ound t op r oduce m o re d ef ined c a l ib ra ted a ge r a nges f o rt h e p o s t 1500 AD p e r iod o fN ew Z ea land p r eh is tory , c ompa r ed t ot h e e xpanded a ge r a nge s o b se rved w hen u s ing t h er e se rvo i rc o r rec t ion c a l ib ra t ion m e thod . T he m ode l led m a r ine c urve i sa r gued t ob e b o th p rec ise a nd a ccu ra te i n c a l ib ra t ing s he l l r a d ioca rbon d a te s f o r N ew Z ea land p r eh i s to ry b a sed o n f ou r o b se rva t ion s . F i r s t , t h e m a r ine s he l l r a d ioca rbon d a te s c a l ib ra ted u s ing t h e m ode l led m a r ine c urve a r e m o r eo f t en i na g reemen t w i th p a i red c a l ib ra ted c ha r coa l d a te s , t h an m a r ine s he l l a ge s c a l ib ra ted u s ing t h e r e se rvo i r c o r rec t ion c a l ib r a t ion m e thod . S econd , t h e mode l led m a r ine c urve s u cces sf u l ly s imu la te s c hange s i nR ( t ) t h rough t ime . T h i rd , AR v a lues f r om t h e a r chaeo log ica l s i te s a na ly sed a r e i na g reemen t w i th t h e c u r ren t v a lue f o r N ew Z ea land . F our th , s he l l d a te s c a l ib ra ted u s ing t h e m ode l led m a r ine c u rve a r e i na g reemen tw i th t h ea r chaeo log ica l e v idence i nd a t ing t h ea r chaeo log ica l d epo s i t s . N ine s he l lf i sh s pec ie s c ommon ly f ound i nN ew Z ea land a r chaeo log ica l s i te s a r e i d en t if ied a sr e l iab le f o r r a d ioca rbon d a t ing . T hough t h e se s pec ie s i n hab i ted av a r ie ty o fe nv i ronmen t s , t h is d i d n o t e f f ec t d a t ing r e p roduc ib i l i ty b e tween s pec ie s . E ven i nl o ca t ions w he r e l i me s tone s t ra ta i sp r edom inan t , n o h a rd w a te r i sd e tec ted . C ha rcoa l a ge s a r e f ound t ob e l e ss r e p roduc ib le t h an m a r ine s he l l f o r d a t ing a r chaeo log ica l d epo s i t s . T h i s i sp robab ly d ue t oi nbu i l ta ge . F i ve a r chaeo log ica l d epo s i t s w he re r a d ioca rbon a ge d i f f e rence s a r e o b se rved b e tween c ha rcoa l a nd m a r ine s he l l s amp le s , a r e f o und t oh ave b een a f f ec ted b y p o s t -depo s i t iona l d i s tu rbance i np reh is to r ic a nd modern t ime s , a nd f r om t h e i n co rpo ra t ion o fs ub -f o s s i l m a r ine s h e l l . A na na ly s is o f4 0p r ev ious ly d a ted a r chaeo log ica l s i t e sw i th p a i r ed c ha rcoa l a nd m a r ine s he l l r a d ioca rbon d a te s i su nde r taken . D ub iou s r a d ioca rbon a ges a r e r e jec ted u s ing ad i sca rd p ro toco l b a sed o n A nde r son ( 199 1) , S p r igg s a nd A nde r son ( 1993 ) a nd S chm id t ( 1 993 , 1 996a ) . E igh t a r chaeo log ica l s i te s r ema in ing a f t e ra pp l ica t ion o ft h e d i sca rd p ro toco l , s how c h rono log ica l a g reemen t b e tween t h e c ha rcoa l a nd ma r ine s he l l d a te s , s uppo r t ing t h e r e l iab i l i ty o f t h e s he l lf i sh s pec ie s i d en t if ied i n t h i s s t udy , a nd u se o f t h e mode l led m a r ine c urve . I n l i gh t o ft h e r e su l t s o ft h e r e sea rch , t h e t ime o fc o lon isa t ion o fN ew Z ea land i sp ropo sed b a sed o n a r chaeo log ica l s i te sw i th a ccep tab le c ha rcoa l a nd m a r ine s he l l r a d ioca rbon c h rono log ie s .

ACKNO WLEDGE MENTS

1w ou ld l i ke t o t h ank t h e f o l low ing p eop le a nd o rgan i sa t ion s f o r t h e i r c on t r ibu t ions a nd s uppor t i n u nde r tak ing t h i s r e sea rch : A ve r i l le a nd C o l in S chm id t , R ebecca O skam , Maud Webbe r , D r . A lan H ogg , D r . T homa s H igham , P rof . K en McKay , P rof . Eme r i tus R oge r G reen , H e len McK innon , D r . F iona P e t chey , Wa r ren G um ley , M ichae lT ay lo r , D r . I a n B a rbe r , D r . R od C lough , D r . R od Wa l lace , P rof . G eof f I r w in , D r . T hegn L adef oged , D r . R od Wa l lace , D r . R oge r S pa rk s , D r . B ruce McFadgen , K ev in J one s , T ony Wa l ton , D o ro thy B rown , P au l S peed ,t h e R oya l S oc ie ty o fN ew Z ea land , t h e U n ive r s i ty o f Wa ika to R ad io ca rbon D a t ing L abo ra to ry , I n s t i tu te o f Nuc lea r S c ience s , N ew Z ea land A r chaeo log ica l C onsu l tan t s L t da nd a l l I w i w ho p rov ided p e rm is s ion t oo b ta in s amp le s f r om t h e s i t e s f o rt h is s t udy .

1 1

L IST OF F IGURES F igur e

P age

2 . 1

C a rbon r e se rvo i r s i nn a tu r e( f rom T ay lo r 1 987 :8 ) .

7

2 . 2

T he h a lf l if eo f"C ( f rom B owman 1 990 :11) .

8

2 . 3

R e la t ion sh ip b e tween r ad ioca rbon a ge s a nd c a lenda r d a te s d e r ived t h rough d a t ing o ft r ee r i ng s . C u rve s s uch a st h i s a r eu sed i nt h ec onve r s ion o f ar a d ioca rbon a ge t o ac a lenda rd a te ( f rom A i tken 1 990 :99 ) .

9

3 . 1

L oca t ion o fa r chaeo log ica ls i te sd i scus sed i nC hap te r3 .

1 4

3 . 2

C ompa r ison o f r a d ioca rbon a ge s o n d i f f e ren t s amp le t y pe s f r om N ew Z ea land a r chaeo log ica l s i t e sb y R af t e re ta l . ( 1972 ) .

1 7

3 . 3

C ompa r i son o fr a d ioca rbon a ge s o n c ha rcoa l , m a r ine s h e l l a nd b one f r om N ew Z ea land a r chaeo log ica l s i te sb y McCu l loch a nd T ro t te r( 1975 ) .

1 8

3 . 4

C ompa r i son o f s amp le t y pe s u sed t o d a te N ew Z ea land s ou the rn A rcha ic a r chaeo log ica l s i t e sb yA nde r son ( 1982 ) .

1 9

3 . 5

A nde r son 's ( 1989 ) c umu la t ive p robab i l i ty c u rve s o fr a d ioca rbon d a te s o n d i f f e r ing s amp le t ypes f r om moa -hun t ing s i te s .

2 2

3 . 6

P rob lems i n r a d ioca rbon d a t ing s he l lf i sh o f d i f f e r ing s pec ie s f r om t h e F ox ton a r chaeo log ica l s i t e ( r ad ioca rbon d a te s h ave b een c a l ib ra ted ) ( f rom A nde r son 1 99 1 :779 ) .

2 3

4 . 1

T ran sve r se s e c t ion t h rough ab i va lve s how ing c a lca r eou s l a ye r s , m an t le f o ld s a nd t h ep e r io s t racum ,w h ich a i d s i ns he l l s e c r e t ion ( f rom B a rne s 1 987 :403 ) .

3 2

4 . 2

S he l l s e c re t ion i n mo l lusc sa ss e en i n ap u lmona te s na i l( Ba rne s 1 987 :351) .

3 2

4 . 3

P roce s s b y w h ich s he l l i sf o rmed b y b i va lve s a nd g a s t ropod s ( f rom B a rne s 1 987 :405 ) .

3 3

5 . 1

Mode l led ma r ine c onven t iona l r ad ioca rbon a ge c u rve s f o r t h e m ixed l a ye r a nd d eep o cean . T he m ixed l a ye rc u rve i su sed t oc onve r t ac a lenda r m a r ine s he l l d a te ( AD X ) i n to a m ode l led m a r ine a ge ( Q ) f o r AR c a lcu la t ion ( f rom S t u ive r e ta l . 1 986 :994 ) .

4 0

5 . 2

AR v a lue sf o ro cean ic r e g ion so ft h ew o r ld c a lcu la ted b y S t u ive re ta l . ( 1986 :995 ) .

4 1

5 . 3

Mode l led ma r ine CRAs v s . a tmo sphe r ic CRAs ( No r the r n H em i sphe r e ) . T h is c u rve i su sed t o c onve r t a n a tmo sphe r ic r a d ioca rbon a ge , i n to a n e qu iva len t mode l led m a r ine r ad ioca rbon a ge ( Q at )f o r AR c a lcu la t ion ( f rom S t u ive r a nd B raz iuna s

4 1

1 993 : 154 ) . 5 . 4

AR v a lues f o r o cean ic r e g ion s o f t h e wo r ld ( f rom S t u ive r a nd B raz iuna s ( 1993 :156 ) .

4 2

6 . 1

L oca t ion s o fa r chaeo log ica l s i te s s amp led f o r c ha r coa l /ma r ine s h e l l p a ir s i nt h i s s t udy .

4 8

6 . 2

L oca t ion o fK okohu ia , No r th land .

4 9

6 . 3

L oca t ion o fK okohu ia a r chaeo log ica l s i te ( 006 /317 ) i nt h eH ok ianga H a rbou r .

4 9

6 . 4

S t ra t ig raphy o fK okohu ia ( 006 /317 ) .

5 0

6 . 5

L oca t ion o fA r ea sA , B( S8 / 17 1) a nd C ( S8 / 16 ) , Whangapoua , A o tea .

5 2

6 . 6

L oca t ion o fA r ea sA , Ba nd C b yt h e Whangapoua e s tua ry , A o tea .

5 2

6 . 7

S t ra t ig raphy o f A rea B ( S8 / 17 1) , s ou the rn b au lk ( e qu iva len t t o s t ra t ig raphy o f A rea A n o r ther nb au lk ) , Whangapoua , A o tea .

5 3

6 . 8

S t ra t ig raphy o fA rea C ( S8 / 16 ) , n or the rn b au lk , Whangapoua , Ao tea .

5 3

6 .9

L oca t ion o fP onu i I s land a r chaeo log ica l s i tes .

5

6 . 10

L oca t ion o fs i t eN 43 / 1 i n Mo tunau B ay , P onu i I s land .

5 6

6 . 11

S t ra t ig raphy o fs i te N 43 / 1 , Mo tunau B ay , P onu i I s land .

5 6

6 . 12

L oca t ion o fs i t e s2 7 a nd N 43 /333 , C rescen t B ay , P onu i I s land .

5 7

6 . 13

S t ra t ig raphy o fs i te 2 7 , C rescen t B ay , P onu i I s land .

5 7

6 . 14

S t ra t ig raphy o fs i te N43 /333 , C re scen t B ay , P onu i I s land .

5 8

6 . 15

L oca t ion o fs i te 1 4 , R abb i t B ay , P onu i I s land .

5 9

6 . 16

S t ra t ig raphy o fs i te 1 4 , R abb i t B ay , P onu i I s land .

5 9

6 . 17

L oca t ion o fs i t e9 5 , S he l ly B ay , P onu i I s land .

6 0

6 . 18

S t ra t ig raphy o fs i te 9 5 , S he l ly B ay , P onu i I s land .

6 0

6 . 19

L oca t ion o fL iga rB ay a r chaeo log ica l s i tes , Go lden B ay .

6 1

6 . 20

S t ra t ig raphy o fs i te N25 /95 , M idden s 1a nd 2 ,L iga rB ay .

6 1

6 . 21

S t ra t ig raphy o fs i te N 25 /26 , L iga rB ay .

6 2

6 . 23

S t ra t ig raphy o f S awp i t P t ( N26 /214 ) , Awa roa I n le t . L aye r s L IB a nd L 1C w e re s amp led f o rd a t ing

6 3

7 . 1

C a l ib ra ted r a d ioca rbon a ges f r om K okohu ia ( 006 /317 ) , L aye r2 .

6 6

7 . 2

C a l ib ra ted r a d ioca rbon a ges f r om K okohu ia ( 006 /317 ) , L aye r3 .

6 7

7 . 3

C a l ib ra ted r a d ioca rbon a ge s f r om K okohu ia ( 006 /317 ) , L aye r4 .

6 8

7 . 4

okohu ia ( 006 /317 ) , L ayer 5 . C a l ib ra ted r a d ioca rbon a ge s f r om K

6 9

7 . 5

nd m a r ine s he l l r ad ioca rbon d a tes f r om L aye r s C a l ib ra ted p oo led m ean c ha rcoa l a 2t o 5a tK okohu ia .

7 0

7 . 6

C a l ib ra ted r a d ioca rbon a ges f r om A rea B ( S8 / 17 1) , L aye r2 , Ao tea .

7 2

7 . 7

C a l ib ra ted r a d ioca rbon a ges f r om s i te N 43 / 1 , L aye rD , P onu i I s land .

7 3

7 . 8

C a l ib ra ted r i te N 43 /333 , L aye rD , P onu i I s land . a d ioca rbon a ge s f r om s

7 3

7 . 9

C a l ib ra ted r a d ioca rbon a ge s f r om S i te 1 4 , P onu i I s land .

7 5

7 . 10

C a l ib ra ted r a d ioca rbon a ges f r om S i te 2 7 , P onu i I s land .

7 5

7 . 11

C a l ib ra ted r a d ioca rbon a ges f r om s i te N 25 /95 , M idden 1 ,L iga rB ay .

7 7

7 . 12

C a l ib ra ted r a d ioca rbon a ges f r om s i te N 25 /95 , M idden 2 ,L iga rB ay .

7 7

7 . 13

C a l ib ra ted r a d ioca rbon a ges f r om s i te N 25 /26 , L iga rB ay .

7 9

7 . 14

C a l ib ra ted r a d ioca rbon a ges f r om S awp i t P o in t ( N26 /214 ) , L aye r s L IB a nd LI C , Awa roa .

7 9

7 . 15

C a l ib ra ted r a d ioca rbon a ges f r om s i te N 43 /333 , L aye rB , P onu i I s land .

8 1

7 . 16

C a l ib ra ted r a d ioca rbon a ges f r om A rea A ( S8 / 17 1) , L aye r2 , Ao tea .

8 1

7 . 17

C a l ib ra ted r a d ioca rbon a ges f r om A rea C ( S8 / 16 ) , L ayer 2 , Ao tea .

8 2

7 . 18

C a l ib ra ted r a d ioca rbon a ges f r om s i te 9 5 , L aye rB , P onu i I s land .

8 3

7 . 19

C a l ib ra ted r a d ioca rbon a ges f r om s i te 9 5 , L aye r D , P onu i I s land .

8 4

v i

7 . 20

C a l ib ra ted r ad ioca rbon a ge s f r om S awp i t P o in t ( N26 /2 14 ) , L aye r s L IB a nd L 1C Awa roa , s how ing i nf luence o n c hrono logy b y i n corpo ra t ion o f s ub -fo s s i l s he l l (Wk -4032 ) .

8 5

7 . 2 1

G raph s how ing p oo led m ean ma r ine s he l l CRA v s . p oo led mean c ha rcoa l CRA f r om t h e a r chaeo log ica l s i te s i n t ab le 7 . 22 , p lo t ted a ga ins t t h e f i xed r e se rvo ir c or rec t ion f o r N ew Z ea land , a nd t h e S t u ive r a nd B raz iuna s ( 1993) mode l led ma r ine c urve f o rt h ep e r iod 2 00 t o7 00 B P .

8 8

7 . 22

P o lynom ia l ( o rde r3 )c urve ( t op ) a nd s t ra igh t l i ne l i nea r r e g ress ion ( bo t tom ) f i t ted t oR ( t )v a lues c a lcu la ted f o rt h e a r chaeo log ica l s i tes d a ted i nt h is s t udy .

8 9

7 . 23

D ecada l a tmo sphe r ic c a l ib ra t ion c urve f o rt h e p e r iod 1 400 c a l AD t o 1 950 c a l AD f r om S t u iver a nd B ecke r( 1993 :41) .

9 0

7 . 24

S imu la ted r ad ioca rbon a ge c a l ibra t ion s u s ing b o th m a r ine s he l l c a l ib ra t ion me thod s b eg inn ing w i th ac onven t iona l m a r ine s he l l r a d ioca rbon a ge o f7 00 ± 4 0 y ea r sB P .

9 1

7 . 25

S imu la ted r ad ioca rbon a ge c a l ib ra t ions u s ing b o th m a r ine s he l l c a l ib ra t ion me thods b eg inn ing w i th ac onven t iona l m a r ine s he l l r a d ioca rbon a ge o f8 00 ± 4 0 y ea r s B P .

9 1

7 . 26

Mode l led ma r ine c a l ib ra t ion c urve f o r t h e p e r iod 1 400 c a l AD t o 1 950 c a l AD f r om S tu ive ra nd B raz iuna s( 1993 :159 ) .

9 2

8 . 1

C a l ib ra ted r ad ioca rbon a ge s f r om Awa roa I n le t( N26 / 18 ) .

1 04

8 . 2

C a l ib ra ted r ad ioca rbon a ge s f r om Ka iwaka P o in tp a( N73 /222 ) , L aye r 1 .

1 05

8 . 3

C a l ib ra ted r ad ioca rbon a ge s f r om P u r ir i ( 1 12 /340 ) .

1 05

8 . 4

C a l ib ra ted r ad ioca rbon a ge s f r om P ur i r i ( T 12 /883) .

1 06

8 . 5

C a l ib ra ted r ad ioca rbon a ge s f r om P ur ir i( 1 12 /885 ) .

1 06

8 . 6

C a l ib ra ted r ad ioca rbon a ge s f r om S hag Mou th ( S 155 /5 ) .

1 07

8 . 7

C a l ib ra ted r ad ioca rbon a ge s f r om T umb ledown B ay ( S94 /30 ) .

1 07

v i i

L IST OF TABLES T ab le

P age

2 . 1

T he e f f ec t o n a9 00 y ea r s B P s amp le w hen c on tam ina ted b y d i f f e r ing a moun t s o f mode rn a nd o ld c a rbon ( f rom C augh ley 1 988 :247 ) .

1 0

3 . 1

V a r ia t ions i n r a d ioca rbon a ge o n d i f f e ren t s amp le t y pe s f r om N ew Z ea land a r chaeo log ica l s i t e s o b se rved b y T ro t te r ( 1967c ) ( ma r ine s he l l r a d ioca rbon d a tes a r er e se rvo i rc o r r ec ted ) .

1 5

3 . 2

T ro t te r ' s ( 1968 ) c ompa r ison o fc ha rcoa l , m a r ine s he l l a nd moa b one r ad ioca rbon d a te s f r om N ew Z ea land a r chaeo log ica l s i te s . ( T ro t te r s ub t rac ted e ach r e se rvo i r c o r r ec ted CRA f r om 1 950 AD t od e r ive y ea r s AD ) .

1 5

3 . 3

S umma ry o fo p in ions o n t h e r e l iab i l i ty o ft h e t h ree m a in s amp le s t y pe s u sed f o r r a d ioca rbon d a t ing N ew Z ea land a r chaeo log ica l s i te s .

2 5

3 . 4

S umma ry o f o p in ions o n s amp le t ype r e l iab i l i ty b a sed o n w ha t m a te r ia l m o s t l i ke ly d a te st h e c u l tu ra le ven tb e ing i n ve s t iga ted .

2 5

3 . 5

R ad ioca rbon a ge sa nd p rovenance o fs amp le sf r om t h e F ox ton moa -hun t ing s i t e .

2 6

3 . 6

R ad ioca rbon a ge sf r om a r chaeo log ica l s i te se xcava ted a t' Avoca P o in t ' .

2 7

4 . 1

McFadgen e ta l . ( 1 994 ) l o ngev i ty o ft r ee a nd s h rub s pec ies u sed f o r r ad ioca rbon d a t ing i nN ew Z ea land .

2 9

4 . 2

L ongev i ty o ft r ee a nd s h rub s pec ies c ommon ly u sed f o rr a d ioca rbon d a t ing i nN ew Z ea land a r chaeo logy .

3 0

5 . 1

R e se rvo i rc o r rec t ion s /ma r ine s he l l s t anda rd s f r om o cean r eg ion sa r ound t h ew o r ld .

3 8

5 . 2

O r ig ina l AR v a lue f o rN ew Z ea land c a lcu la ted b y S t u ive re ta l . ( 1986 :1020 102 1) .

4 0

5 . 3

C ur r en t AR r e sea r ch a r ound t h ew o r ld .

4 2

5 . 4

T ab le 4 f r om D ye ( 1994 :55 ) " A MS D a te s o n Ma r ine S he l ls f r om P l e i s tocene L ime s tone a nd H o locene V o lcan ic C oa s t " .

4 4

6 . 1

R ad ioca rbon d a te s f r om L aye r4 ,S p i tC ,N 43 / 1 , P onu i I s land .

5 4

6 . 2

R ad ioca rbon d a te sf r om L aye rL 1C , S awp i t P o in t( N26 /2 14 ) , Awa roa .

6 3

7 . 1

C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd ma r ine s h e l l f r om K okohu ia , L aye r2 .

6 5

7 . 2

C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd ma r ine s he l l f r om K okohu ia , L aye r3 .

6 6

7 . 3

C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd ma r ine s he l l f r om K okohu ia , L aye r4 .

6 7

7 . 4

C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd ma r ine s he l l f r om K okohu ia , L aye r5 .

6 8

7 . 5

P oo led m ean c ha r coa l a nd m a r ine s he l l r ad ioca rbon a ge s f r om e a ch c u l tu ra l l a ye r a tK okohu ia .

6 9

7 . 6

P oo led c ha rcoa l a nd m a r ine s he l l d a tes f r om l a ye r s 2t o 5a tK okohu ia h ave b een s t a t i s t ica l ly c omb ined t o o b ta in a n o ve ra l l a ge f o r t h e s i te ( e r ro r i n c a l ib ra t ion c u rve i n co rpo ra ted i nc a lcu la t ions a s r equ i red i n aC a se 2 s i tua t ion ) . T he T e s t S t a t i s t ic s s how t h a t t h e p oo led c ha rcoa l d a te s f r om e ach l a ye r a r e a s ag r oup s t a t i s t ica l ly d i s t ingu i shab le , i mp ly ing t h a tn o ta l t h ec u l tu ra l l a ye r sw e re d epo s i ted a tt h es ame t ime . *=Wa rd a nd W i lson ( 1978 ) .

7 0

i x

7 . 7

C lus te r a na ly s is o n p oo led mean c ha rcoa l r a d ioca rbon d a tes f o r e ach l a ye r o ft h e K okohu ia s i te ( c a l ib ra t ion c urve e r ro r t a ken i n to a ccoun t i nc l us te r a na ly s is ) . T he

7 0

d rop i n t h e Av a lue i n L ayer 4 f o r t h e c ha rcoa l c hrono logy i n d ica tes t h a t t h e p oo led c ha rcoa l d a te s f r om L aye r s 2a nd 3 c an b e g rouped s epa ra te ly f r om t h e p oo led c ha rcoa l a ges i nL aye r s 4a nd 5 . *= Wa rd a nd W i lson ( 1978 ) ; #= W i lson a nd Wa rd ( 1981) . 7 . 8

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s h e l l f r om A rea B ( S8 / 171) , L ayer 2 , Ao tea .

7 1

7 . 9

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s he l l f r om N 43 / 1 , L aye rD , P onu i I s land .

7 2

7 . 10

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s he l l f r om N 43 /333 , L ayer D , P onu i I s land .

7 4

7 . 11

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s he l l f r om S i te 1 4 , L aye rD , P onu i I s land .

7 4

7 . 12

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s he l l f r om S i te 2 7 , L aye rD , P onu i I s land .

7 4

7 . 13

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha r coa l a nd ma r ine s he l l f r om M idden 1 ,s i te N25 / 195 , L iga rB ay .

7 6

7 . 14

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s he l l f r om M idden 2 ,s i te N25 / 195 , L iga rB ay .

7 6

7 . 15

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd ma r ine s he l l f r om N 25 /26 , L aye r4 ,L iga rB ay .

7 8

7 . 16

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ge s o n c ha rcoa l a nd m a r ine s he l l f r om S awp i t P o in t( N26 /214 ) , L aye r s L1 B a nd L 1C , Awa roa .

7 8

7 . 17

C onven t iona l r a d ioca rbon d a tes a nd c a l ibra ted a ges o n c ha rcoa l a nd m a r ine s he l l f r om N43 /333 , L aye rB , P onu i I s land .

8 0

7 . 18

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd m a r ine s he l l f r om A rea A ( S8 / 171) , L aye r2 ,A o tea .

8 0

7 . 19

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha r coa l a nd m a r ine s he l l f r om A rea C ( S8 / 16 ) , L aye r2 , Ao tea .

8 2

7 . 20

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd m a r ine s he l l f r om S i te 9 5 , L aye r s Ba nd D , P onu i I s land .

8 3

7 . 21

C onven t iona l r a d ioca rbon d a tes a nd c a l ib ra ted a ges o n c ha rcoa l a nd m a r ine s he l l f r om S awp i t P o in t( N26 /214 ) , Awa roa .

8 5

7 . 22

R ese rvo i r a ges a nd AR v a lues c a lcu la ted f o r a r chaeo log ica l s i tes i n t h is s t udy w h ich h ad a ccep tab le p a i red c ha rcoa l a nd ma r ine s he l l r a d ioca rbon a ge s .

8 7

8 . 1

S he l lf i sh s pec ie s f ound t o b e r e l iab le i n t h is s t udy f o r r a d ioca rbon d a t ing N ew Z ea land p r eh is to ry .

9 6

8 . 2

N ew Z ea land a r chaeo log ica l s i te s w i th p a ired c ha rcoa l /ma r ine s he l l r a d ioca rbon d a te s f r om t h es ame p rovenance .

1 02

8 . 3

A ccep tab le p a i red c ha rcoa l a nd ma r ine s he l l r ad ioca rbon d a te s f r om N ew Z ea land a r chaeo log ica l s i te s .

1 04

8 . 4

R e se rvo i r a ge s a nd AR v a lues c a lcu la ted f o r p rev ious ly d a ted N ew Z ea land a r chaeo log ica ls i tes w i th a ccep tab le c ha rcoa l a nd ma r ine s he l l p a ir s .

1 08

8 . 5

AR v a lues c a lcu la ted f r om a r chaeo log ica l s i tes a na lysed i nt h is s t udy s t a t is t ica l ly

1 08

c ompa red w i th t h ec ur ren tN ew Z ea land v a lue f r om H igham a nd H ogg ( 1995) .

CHAPTER 1 I NTRODUCT ION " T he a g eo fi mp lemen t sm ad eb ym an h a so f ten t ob ed e term ined , i nd eed i nm any c a se sc an o n ly b ed e te rm ined , b ya c on s id e ra t ion o ft h eo b jec t s w i th w h ich t h ey h ave b een d i scove red . Among s tt h e se t h em o s ti mpor tan ta re t h et e e th a nd b one s o fe x t inc t mamma l s ." B e r t ram C .A . W ind le ( 1904 : 4 5 )

RELAT IVE AND ABSOLUTE : DAT ING NE W ZEALAND PREH ISTORY T he i n t roduc t ion o f r a d ioca rbon d a t ing t o a r chaeo logy b y L ibby a nd h i sc o l league s i n1 949 ( L ibby e ta l . 1 949 ) , w a s t o a f f ec t t h e i n te rp re ta t ion o f p r eh is to ry w o r ldw ide . I tm ean t t h a t a r chaeo log is t s w ou ld n o l o nge r h ave t o r e ly u pon r e la t ive d a t ing t e chn ique st oo rde rt h ep a s t . I nr e la t ive d a t ing , t h e a ge o f a n a r chaeo log ica l s i te c ou ld o n ly b e d e r ived t h rough s t r a t ig raphy , a nd a c ompa r i son o f a r tef ac t t ype s . Whe re s im i la r a r tef ac t s w e r e f o und i ns i tes g rea t d i s tance s a par t , i tc ou ld b e a rgued t h a t t h e s i te s w e re o ccup ied a ta s im i la rt i me i np reh i s to ry . T he se a r tef a c tt y pe sw e re t h en t i ed i n to h i s to r ic r e co rd s t o d eve lop c a lenda r c h rono log ie s f o r s i tes a nd t h e r ef o re r eg ion s . P o t tery w a s c ommon ly u s ed t oc on s t r uc t r e la t ive p r eh is to r ic c h rono log ie s b ecause d i s t inc t ive p a t te rn s o f m anuf ac tu re w e re r e ad i ly c ompa rab le b e tween d i s tan t a r chaeo log ica l a r ea s . T h i s m e thod , t h ough , w a s c onf ined t o a r ea s s uch a s t h e Med i te r ranean , t h e M idd le E a s t , E u rope , a nd t h e Ame r ica s , w he re p o t te ry a nd a nc ien t h i s to r ic r e co rd s c ou ld b e u sed i np a ra l le l . I n c on tex t s w he re n o w r i t ten r e co rd s e x is ted , o r w he re p o t t e ry w a s e i the r n on -ex i s ten t o r n o t c ommon ly f o und i np r eh i s to r ic s i te s , s uch a s i nP o lyne s ia , t h e c h rono log ica l p l a cemen t o f t h e se s i te s i n w o r ld p r eh is tory d epended o n s t ra t ig raphy a nd a r tef ac t s , c omb ined w i th l o ca lm y th , o ra lt r ad i t ion a nd g enea log ica l c h rono log ie s ( s ee G o l son 1 955 :115 , 124 ) . A rchaeo logy w a s , t h e ref o re , r e s t r ic ted c h rono log ica l ly t om a te r ia l a c tua l ly u ncove red b y t h e a r cha eo log is t o r a nc ien t h i s to r ian w h ich w a s d i s t inc t ive o f ac er ta in c a lenda rp e r iod . I n New Z ea land , t h e e a r l ie s t a t temp t s t od a te a r chaeo log ica l s i tes w e r e b y H aa s t i nt h e l a te 1 9 th c en tu ry . H aa s t b e l ieved t h a tt wo d i f f e ren tp reh i s to r ic g roup sh ad o ccup ied t h e s i te s o f R edc l if f sa nd S hag R ive r Mou th : t h e Moa -hun te r s ,w ho w e re r ep resen t ed b y c u l tu ra l r ema in s d om ina ted b y e x t inc t a v if auna , a nd t h e S he l lf i sh e a te r s ( o r l a te r Mao r i ) , w ho w e re r ep resen ted b y ap redom inance o f m a r ine f a una ( s ee H aa s t 1 875a , 1 9 75b , 1 875c ) . H aa s t s ugge s ted t h a t t h e p e r iod o f t ime s epa r a t ing t h e se t wo c u l tu ra l g roup s s panned m any t housand so fy ea r s b a sed o n t h e s i t e 's s t ra t ig raphy , a r tef ac t s , a nd t h e a b sence o fm oa i nt h e u ppe r l a ye r s . A t t h e c l o se o f t h e 1 9 th c e n tury , g eo log ica l e s t ima te s o ft ime w e r e m ak ing w ay f o r e t hnog raphy t od a te a r chaeo log ica l f i nd s , r e duc ing t h e p re sence o f p eop le i nN ew Z ea land t o w i th in t h e l a s t t housand y ea r s ( s ee A nde r son 1 989 :106 107 ) . I n t h e e a r ly 2 0 th c en t u ry , t h e i n co rpo ra t ion o f o r a l t r ad i t ion t o d eve lop r e la t ive c h rono log ie s f o r a r chaeo log ica l f i nd s w a s c ommon , l e ad ing t ot h e p ropo s i t ion o f an umbe r o f c o lon i sa t ion a nd o r ig ins t h eo r ie s( s ee B a rbe r 1 995 ) .

P o s s ib ly t h e mo s t w e l l k nown o f t he se e a r ly t h eo r ie s w a s t h a t p ropo sed b y S m i th a nd B e s t ( Sm i th 1 92 1; B e s t 1 9 14 , 1 9 16 ; B a rbe r 1 995 :360 ) . Sm i th a nd B e s t u sed o ra l t r ad i t ion t o a rgue t h a t t h e f i r s t s e t t le r s i n N ew Z ea land w e re t h e Mo r io r i ( Ma r u iw i ) f r om Me lane s ia . When N ew Z ea land w a s c o lon ised b y Mao r i f r om P o lyne s ia l a te r i np reh is to ry , t h e Mo r io r i e i the r f l ed t o t h e C ha tham I s land s t o a vo id b e ing s ubdued , o r m ixed w i th t h e ' s upe r io r ' Mao r i p eop le . A n a l ter na t ive t o t h i s t h eo ry w a s p ropo sed b y S k inne r ( 1 921 , 1 923 ) , w ho e mpha s i sed t h e i mpo r tance o ft h e a r chaeo log ica l r e co rd . S k inne r a na ly sed c u l tu ra l r ema ins o fC ha tham I s land Mo r io r i a nd S ou ther n N ew Z ea land Moa -hun te r s . H e s howed t h a t t h e m a te r ia l c u l tu re o f Mo r io r i a nd Mao r i w e re E a s t P o lyne s ian i n o r ig in , a nd t h e re w a s n o r e la t ionsh ip b e tween Mo r io r i c u l tu r e a nd Me lane s ia ( Sk inne r 1 92 1 , 1 923 ; T ev io tda le 1 932 , 1 938 ; B a rbe r 1 995 :36 1-362 ) . When t h e f i r s t N ew Z ea land a r chaeo log ica l ma te r ia l w a s r ad ioca rbon d a ted i n t h e 1 950 s , t h e p r inc ipa l q ue s t ion s c oncer ned t h e d a te o f f i r s t c o lon i sa t ion b y P o lyne s ian s a nd t h e c h rono log ica l p l a cemen t o f s pec if ic p r eh is to r ic e ven t s ( Go lson 1 955 :133 133 ) . N ew Z ea land w a st ot h e f o ref ron to f r e sea r ch o n t h e n ew d a t ing m e thod a nd i t s u se i n a r chaeo logy ( Go l son 1 955 :130 ) . I n t h e m id 1 950 s , a r ad ioca rbon d a t ing c omm i t tee w a s f ounded b y t h e N uc lea r S c ience s L abo ra to ry o f t h e D epar tmen t o f S c ien t if ic a nd I ndu s t r ia l R e sea r ch ( DS IR ) ( now c a l led t h e I n s t i tu te o f G eo log ica l a nd N uc lea r S c ience s ( IGNS I) a nd N ew Z ea land a r chaeo log is t s ( Leach p e r s . c omm . 2) .T he f unc t ion o f t h i s c omm i t tee w a st os e lec t s amp le s r e cove red b y a r chaeo log i s t s f o r r a d ioca rbon d a t ing t o e nsu r e t ha t t h e s amp le s w e re a s soc ia ted w i th t h e a r chaeo log ica l e ven t b e ing d a ted . T he c omm i t tee a l so i n i t ia ted as t udy o n t h e r e l iab i l i ty o fv a r ious s amp le t ype s f o r r a d ioca rbon d a t ing . O ne o f t h e se e a r ly s t ud ies b y L ocke rb ie i n1 957 , e xam ined v a r ia t ions i na ge so n moa b one , m a r ine s he l l a nd c ha r coa l f r om t h ree o ccupa t ion l a ye r s a t t h e S ou th I s land moa -hun t ing s i te o f P ounawea ( Locke rb ie 1 959 , 1 980 ; s e e C hap te r 3 ) . S uch s t ud ie s , i n c o l labo ra t ion w i th t h e s c reen ing c omm i t tee , p rov ided a n i n i t ia l b a se f o r t h e d eve lopmen t o f a n a b so lu te c h rono logy f o rN ew Z ea land p r eh i s to ry . Rad iocarbon Da t ing a nd t he New Z ea land P reh is tor ic S equence I n 1 959 , G o l son c ompa r ed a r tef ac t t ype s b e l ieved t o b e t yp ica l o f t h e f i r s t c o lon ise r s o f N ew Z ea land f r om

If o rt h is s t udy ,t h e a bb r ev ia t ion 1 GNS r e f e r st ot h e D S IR , I NS , I GNS a nd R a f t e rl a bo ra to ry . 2

D r . B .F . L ea ch , Mu seum o fN ew Z ea land , We l l ing ton .

I n troduc t ion

CHAPTER I

b e l ieved t h a t t h e s i te w a s p o s t -f l ee t i n o r ig in a nd w a s p o s s ib ly o ccup ied a s l a te a st h e e a r ly 1 800s ( Duf f 1 956 :80 ) . When c ons ide r ing t h e r a d ioca rbon e v idence , D uf f c onc luded :

r a d ioca rbon d a ted a r chaeo log ica l s i t e s ( s uch a s Wa irau B a r Moa -hun t ing s i te i n t h e S ou th I s land ) , w i th a r tef ac t s f r om s i te s t h ough t t o b e t yp ica l o f l a te r Mao r i s e t t lemen t a nd w ho se f o rms w e re s t i l l b e ing u sed b y Mao r i w hen C ook a r r ived ( s uch a s f ound a t O rua rang i i n t h e N or th I s land ) ( Go lson 1 959 :29 -74 ) . H is i n te rp re ta t ion r e p r esen ted a t u rn ing p o in t i nN ew Z ea land a r chaeo logy . G o l son p ropo sed t h e u se o f t h e t e rms A rcha ic a nd C la s s ic t o d e sc r ibe t h e p r eh i s to r ic s equence o fN ew Z ea land , w i th t h e r a d ioca rbon d a te s a va i lab le p rov id ing a t e rm inu s a n te q uem f o r t h e s equence ( wh ich p r ev ious ly c ou ld o n ly b e o b ta ined t h rough o ra l t r ad i t ion ) ( Go lson 1 959 :36 , 4 7 ) . T he a r tef ac t s n ow b ecame m a rke r s i nr e la t ive c h rono log ie s f o r p r eh is to r ic N ew Z ea land s uppor ted b yt h e r ad ioca rbon d a t ing t e chn ique . T h is m ean t r e g iona l c h rono log ie s f o r N ew Z ea land p reh is to ry c ou ld n ow b e c ons t ruc ted i n dependen t o fg enea logy o r o ra l t r ad i t ion , a nd t h a t e a r ly s i te s w e re n o t s imp ly t ho se w h ich c on ta ined moa r ema ins ( Go lson 1 959 :36 ) .

" T he l i m i ta t ion s o ft h e r ad iocarbon m e thod f or t h e i mmed ia te p a s t a r es e en i nR af ter ' sa t tr ibu t ion o f as amp l e o ft u s sock b edd ing f rom S he l ter A , T akahe V a l ley , t o 10 6 0y ea r sf rom 1 955 ( f rom A .D . 1 785 t o 1 905 ) . A s sum ing 1 905 t o b e i mpo s s ib le , w ef i nd t h a t t h e e ar l ier d a te d oe s s uppor t t h e h ypo the s i s o fa n e i gh t een th -cen tury m ig ra t ion a d vance o n o t her g round s . I nd eed , i t s t r eng then s S k inner ' s p ropo s i t ion t ha t t h i s o ccupa t ion w a s i nd eed p o s t E uropean . T he a noma ly s of r equen t ly e ncoun tered i nr ad iocarbon a na ly s i s i si l u s t ra ted f or t h i s s i te b y D r . R af t er ' s d e te rm ina t ion o f s t r ip s o ft o tara b ark , o bv iou s ly f rom t h es ame c u l tura l l e v e l a s t h e t u s sock , a s 7 00 ± 6 0y ear sf rom 1 955 ( A .D . 195 t o 1 315 ) . I ti sa f a i r a s sump t ion h ere , h ow ev er , t ha t t h e b ar k w a s s t r ipped f rom a l r ead y a ged o r d ead t r ee s e ncoun ter ed o n t h e s hor e s o fL ake T e A nau ." ( Duf f1 956 : X 1 1 ) .

T akehe V a l ley i lus t ra ted t h e p rob lem s a s soc ia ted w i th t h e u se o fr a d ioca rbon d u r ing t h is p e r iod . T he se p rob lem s c ame f r om t wo a r ea s : 1 )p rovenance o f t h e s amp le s o b ta ined b y a r chaeo log is t s f o r d a t ing s i te s , a nd 2 ) t h e r e l iab i l i ty o f c ha r coa l , m a r ine s he l l a nd b one f o r r ad ioca rbon d a t ing a r chaeo log ica l c on tex t s( s ee C hap te r3 ) .

G o lson ( 1959 ) , t h e r ef o re , h ad n o t o n ly p roduced aw o rkab le c u l tu ra l s equence f o r N ew Z ea land p r eh i s to ry ( wh ich h e r e cogn ised a s b e ing f l ex ib le a s mo re d a ta w a s m ade a va i lab le ) , b u t h e e mpha s ised t h e i mpo r tance o f t h e r ad ioca rbon c h rono logy i n t h e d eve lopmen t o f h i s A r cha ic a nd C la s s ic P ha se s , a l ong s ide t h e a r t if ac tua l e v idence ( Go lson 1 986 ; G roube 1 993 :6 17 ) . H oweve r , a s Go lson a nd o t he r N ew Z ea land a r chaeo log i s t s s oon f ound , t h e r ad ioca rbon d a t ing t e chn ique w a s a sn ew t os c ience a s i tw a s t oa r chaeo logy .

A t T akehe V a l ley , f o r e xamp le , t h e e x a c t p rovenance o ft h e s amp le s w a s d ub ious . A lso , t h e s i te w a s o pen ly e xpo sed t o t h e e nv i ronmen t ( t he S he l te r Ad e sc r ip t ion i mp ly ing ac ave s i tua t ion w h ich t h e s i te w a s n o t ) a nd n o p o s t -depo s i t iona l d i s turbance o ft h e s i te h ad b een t a ken i n to a ccoun t b y D uf f . B ecause t h e r a d ioca rbon d a te s f r om t h e s i t e w e re i nc onf l ic t , D uf fh ad s e lec ted t h e r a d ioca rbon a g e w h ich w a s i mpo r tan t t o h i s o wn i d ea o f t h e N ew Z ea land p r eh is to r ic s e quence , a nd s uppo r ted t h is u s ing p o s t -F lee to r a lt r ad i t ion 3.

F rom 1 959 t ot h ee a r ly 1 970 s , a r chaeo log i s t sw e re s t rugg l ing t o p l ace a r chaeo log ica l s i te s i n to e i the r t h e A r cha ic o r C la ss ic P ha se s o f N ew Z ea land p r eh i s to ry , w hen t h e r ad ioca rbon c h rono log ies f r om t h e i r s i t e s w e re c ons ide red a l ong s ide a r tef ac t t y pe s t hough t t o b e t y p ica l o f c e r ta in p ha se s( s ee C hap te r3 ) . T h is q uanda ry b rough t a bou t c onf l ic t b e tween G o l son 's c u l tu ra l s equence b a sed o n a r tef ac t t ypo log ie s a nd r ad ioca rbon d a ta , a nd r e la t ive a ges f o r s i te s b a sed o n a r tef ac t a s semb lage s a nd o r a l a nd t r ad i t iona l a ccoun t s ( s ee D uf f 1 962 :205 -209 ) . O ne a r chaeo log ica l s i te w h ich c onf l ic ted w i th G o lson 's c u l t u ra l s e quence w a s t h e T akehe V a l ley s i te , w h ich w a s om i t ted b y G o l son ( 1959 ) i n t h e d eve lopmen to fh i s c u l tu ra l c h rono logy .

T he r a d ioca rbon c hrono logy o f Nga ro to s wamp p a w a s a l so h i nde red b y u n re l iab le p rovenanc ing o f d a ted m a te r ia l ( Schm id t 1 993) . E xcava ted d u r ing t h e l a te 1 960 s , N ga ro to w a s t h e d eepes ts t ra t if ied a r chaeo log ica l s i t e i nN ew Z ea land a t t h e t ime , w i th c u l tu ra l m a te r ia l s p ann ing a d ep th o f 4 m e te r s ( Shawc ro s s 1 968 ) . I tw a s a l so t h e p a s i te w he re t h e f amous Mao r i c a rv ing U enuku w a s f o und i n 1 906 ( Be s t a nd A nde r son 1 926 :70 ) . B ecau se o f p oo r p r ovenanc ing o f t h e d a ted c ha r coa l a nd m a r ine s he l l s amp les , i tw a s u nc lea r w he the r o ccupa t ion o ft h ep a b egan e i the r 8 00 o r2 50 y ea r s a go , a s i tc ou ld n o t b e d e te rm ined w h ich s amp le c ame f r om t h e b a sa l l a ye r , a nd w h ich c ame f r om o ne o ft h e u ppe rl a ye r s ( Schm id t 1 993) . O takan in ip aw a s a no the re xamp le i nw h ich u n r e l iab le p rovenanc ing o f t h e m a t e r ia l d a ted i mp l ied a p r eh is to r ic s i te w a s c on s t r uc ted i n p o s t -con tac t t ime s . T he e xcava to r s o f t h e p a w i shed t o d a te t h e v a r iou s p ha se s o f f o r t i f ica t ion , a nd s o t ook s amp le s f r om p r e se rved p a l i sade p o s t s f ound d u r ing e xcava t ion . B u t w ood t hough t t o b e a P e r iod I I p a l i sade p o s tw a sf ound a f t e rr a d ioca rbon d a t ing t o h ave d e r ived f r om a moder n f e nce p o s t , t hus n o t o n ly t h row ing i n to d oub t t h i s p a r t icu la r r a d io ca rbon s amp le , b u t t h e r ema inde r o f t h e s amp les s e lec ted a s w e l l ( Be l lwood 1 973 :173 ) .

I n 1 949 , w h i le u nde r tak ing a f i e ld s u rvey i nT akahe V a l ley i nt h e S ou th I s land , K . Me ir s a nd R .A . F a I la f o und f e a the r s o f av a r ie ty o fn a t ive b i rds p ro t rud ing f r om t h e d us t f l oo r o f al i me s tone c ave ( l a te rt ob e c a l led S he l te r A ) . I nve s t iga t ion u ncove red s co rched v er teb rae o f t h e s ma l l b u sh moa Mega lap teryx a sw e l l a s as e c t ion o fp e lv is w i th e v idence o f c u t m a rk s ( s ugge s ted o n e xam ina t ion b y S k inne r a s b e ing c aused b y am e ta l k n if e )( Duf f1 956 :76 -79 ) . F ound a l ong s ide t h e Mega lap teryx b one s a nd o t he r a v ian f a una r ema in s o n a b edd ing o ft u s sock , w a s as anda lm ade f r om p l a i ted f l ax , f l ax n oo se s , ab i rd l u re m ade f r om w eka f e a the r s , a nd ap o in ted f i re s t ick ( Duf f 1 956 :76 ) . D uf fl a te r e xcava ted S he l te r Ai n 1 950 a nd 1 951 t o c onf i rm t h e s t ra t ig raphy o ft h e s i te , a nd f ound f l ake sf r om a na dze a nd al a rge f l ake t o o l . H e s aw t h a t t h e d epo s i t w a s o n ly 1 2 .7cm i nd ep th , c onf ined t o as qua re m e t re , a nd t h e ref o r ep robab ly r ep re sen ted e i the r as i ng le v i s i t o f al a rge h un t ing p a r ty , o r b r ief v i s i t s b y as ma l le r g roup o ve r af ew y ea r s( Duf f 1 956 :77 -79 ) .

L a t e ra na ly s i so ft h eT akahe V a l ley s i te a nd f u r the rd a t ing b yO 'R egan ( 1992 :172 176 ) , d e r ived r ad ioca rbon a ge so f( NZA -2228 ) 6 11 ± 5 1 y ea r s B Po n f e a the r s , t u s sock a nd b eech l e ave s c omb in ed ,a nd ( NZA -2227 )6 28 ± 3 9y ea r s B Po n as ma l l p i ece o fb one f r om t h eb u t che red Mega lap t e ryx i s ch ia l p roce s s . 3

I n i n terp re t ing t h e c h rono logy o ft h e s i t e , D uf fd oub ted t h a t t h e c u tm a rk so nt h e moa p e lv is w e re f r om am e ta l k n if e , b u t

2

CHAPTER 1

I n t roduc t ion

T he a noma lou s r a d ioca rbon c h rono log ie s f r om t h e T akehe V a l ley moa -hun t ing s i te a nd N ga ro to a nd O takan in i p a , w e r e , t h e ref o r e , d ue t o d ub iou s s amp le p rovenanc ing , a nd t h e r e su l t s w e r e n o t t h e f a u l t o f t h e r a d ioca rbon m e thod i t s e lf . T hough s c ien t if ic e xcava t ion t e chn ique s w e re i n t roduced t o N ew Z ea land d u r ing t h e m id 1 950 s , s ome a r chaeo log is t s w e re n o t c on s ide r ing t h e i mp l ica t ion s o f u n r e l iab le p r ovenanc ing o f s amp le s t a ken f o r r a d ioca rbon d a t ing ( Go l son 1 955 :349 ; G o lson 1 986 ; G roube 1 993 :6 17 ) .

A rcha ic , a nd t h e e x i s tence o f A rcha ic f a una s uch a s moa , i n to t h e C la s s ic . T he r e l ic w ood p rob lem w a s a l so c au s ing s amp le t ype s t ud ie s , s u ch a st h o se u nder taken b y L ocke rb ie ( 1959 , 1 980 ) , t o b ecome p r ob lema t ic ( s ee C hap te r 3 ) . Q ue s t ions a bou t t h e r e l iab i l i ty o f s amp le t y pe s b e ing d a ted c ou ld n o t b e a n swe red w i th c onf idence . C ha rcoa l , w ood , m a r ine s he l l a nd b one s amp le s w h ich w e r e r a d ioca rbon d a ted f r om t h e s ame p rovenance s ome t ime s s howed v a ry ing a ge s , a nd t hough t h eb one o rm a r ine s he l l d a te s , f o re xamp le , may h ave b een c on s i s ten t ly c o r rec t ,t h is c onc lu s ion c ou ld n o t b ej u s t if ied d ue t ot h e v a ry ing r e su l t s o fc ha r coa l a ges f r om s ame c on tex t . T he se i s sue s w e r e a dd i t iona l ly c onf ounded b y t h e s hor t p reh is to r ic t ime s pan f o r N ew Z ea land w h ich r e qu i r ed a r e l iab le s amp le t y pe f o r r a d io ca rbon d a t ing p reh i s to r ic e ven t sw i th in t h e l a s t 1 000 y ea r s .

I n m any c a se s , d e sp i te r a d ioca rbon a ge s h av ing a ccu ra te p r ovenance , d a tes w e re f ound t ob e t o o o ld b ecause o ft h e m a te r ia l b e ing d a ted ( s ee C hap te r 3a nd 4 ) . T h is s i tua t ion o c cur red a tT i romoana p a e xcava ted b y F ox f r om 1 974 t o 1 9 75 ( Fox 1 978 ) . H ere ,t h er a d ioca rbon a ge so n c ha rcoa l a nd w ood f r om p i t s t ruc tu re s s t r e tched b a ck t o 3 530 ± 9 0 y ea r s B P ( NZ -19 13 ) , w i th o ne r a d ioca rbon a ge o f 1 050 ± 9 0 y ea r s B P ( NZ -19 14 ) f r om t he p o s t o f ap i t a ccep ted a st h e e a r l ie s t e v idence o f a g r icu l tu re i n t h e N o r th I s land ( Fox 1 9 78 :1 ,28 ,50 ) . T he p o s t s d i d c ome f r om t h e p rovenance d e sc r ibed , b u t t h e t imbe r s p roduced g r ea t ly v a ry ing a ge s b ecause t h e p a l isades u sed i np r eh i s to ry c ame f r om a nc ien t t o ta ra l og s . T he 1 050 ± 9 0 y ea r s B P ( NZ 19 14 ) a ge w a s a c cep ted b ecau se a tt he t ime N ew Z ea land w a s b e l ieved t o h ave b een s e t t led 1 000 y ea r s a go ( s ee D av id son 1 984 :123 1 2 5 ) .

C u l tu ra l s equence s f o r a r chaeo log ica l s i te s w e re t h e r ef o re d ependan t o n w he the r t h e r a d ioca rbon a g e s w e re b e ing a ccep ted o r r e jec t ed b y a r chaeo log is t s . Of t en o b serva t ions w e re m ade t h a t c ha r coa l d a te s w e re t o o o l d b ecau se o fr e l ic w ood , b u t a r chaeo log i s t s c on t inued t o s e lec t c ha rcoa l a nd w ood s amp le s w i thou t c ons ide ra t ion o f i n bu i l t a ge 5 u n t i l a f t e r d a t ing h ad b een u nde r taken ( s ee T ro t te r 1 968 ; L aw 1 97 1 ; R af t e re ta l . 1 9 72 ; s e eC hap te r3 ) . O the rd a t ing t e chn ique sw e re o f t en u sed t oa i d i ni n te rp re t ing r ad ioca rbon c h rono log ie s . S ome a r chaeo log i s t s i n co rpo ra ted o ra l t r ad i t ion o r h i s to r ic e v idence a s am eans o f e i the r j us t if y ing o r o m i t t ing r a d ioca rbon e v idence ( Duf f 1 956 , 1 96 1 ; T ro t te r 1 967a : 14 1 , 1 967b ; F ox 1 978 ) . A r tef ac t t ype s a ga in b ecame o f c en t ra l i mpo r tance i n p rov id ing r e la t ive a ge s f o r s i te s , s u ch a sD uff s( 1959 ) a dze t y pe s , o r H ja rno 's ( 1967 ) f i sh h ook c h rono logy , a st h ey h ad b ef o r e r a d ioca rbon d a t ing ( s ee G reen a nd S hawc ro s s 1 96 1 :2 10 -2 13 ; G reen 1 962 :8 16 ) . T he p o s s ib le a ge o fp aw e re r e la t ive ly d a ted b y a b e l ief t h a t mo re c omp lex f o rms w e r e l a te r d eve lopmen t s i n N ew Z ea land p r eh i s to ry ( G roube 1 970 ; S chm id t 1 993 ) . I d en t if ica t ion o f t h e K aha roa A sh , t h en d a ted t o c a . 9 00 y ea r s B P ( Pu l la r 1 9 59 , 1 962 ) , t h e R ang i to to A sh f a l l o fc a . 6 00 y ea r s B P( Law 1 975 ) , o rt h ep r e sence o fL o ise l 's p um ice ( Law 1 975 :49 ) w e r e o t he r c h rono log ica l m a rke r s a l so e mp loyed . O b s id ian h yd ra t ion w a s i n ve s t iga ted a s a t e chn ique f o r d a t ing s i te s , b u t w a s n o t s u cce s sf u l d ue t o i s sue s s uch a s t h e e f f ec t o f t empe ra tu r e a nd o b s id ian c ompo s i t ion o n h yd ra t ion r a te ( Amb ro se a nd G r een 1 962 :247 -248 ; G r een 1 962 ) . F l uo r ine a na ly s is o f b one w a s a t temp ted b u t w a s f o und n o t t ob e a ccu ra te e nough f o r N ew Z ea land p r eh is to ry ( T ro t te ra nd Ma l thu s 1 967 :151157 ) .

T he p rob lem o f s amp le p rovenance c ou ld o n ly b e s o lved t h rough g ood e xcava t ion t e chn ique ,a nd s ow a sd ependen to n t h e e xcava t ion s k i l l o f t h e a r chaeo log is t . T he r e l iab i l i ty o f v a r ious s amp le t ypes f o r d a t ing , h oweve r , w a s p rob lema t ic . A s a r chaeo log is t s w e re a dv i sed b y t h e N ew Z ea land G eo log ica l S u rvey t ha t c ha r coa l a nd w ood w e re t h e mo s t p r ef e rab le m a te r ia l f o r d a t ing ( Bu i s t 1 962 :249 ) , t h e ma jo r i ty o fr a d ioca rbon d a tes f r om a r chaeo log ica l s i te s p r io r t o 1 976 ( s ee b e low ) c omp r ised t h e se s amp le t ype s ( s ee A nde r son 1 9 89 ; S chm id t 1 993 , 1 996a ) . H ence , m any o ft h e p rob lems w i th r ad ioca rbon c h rono log ie s f r om s i t e s w e re a t t r ibu ted t o t h e se ma te r ia l s . A l though d a te s o n c ha rcoa l o r w ood w h ich w e re s i gn if i can t ly o lde r t h an e xpec ted w e re p ropo sed a s b e ing d ue t o r e l ic w ood , s u ch a s a t T i romoana , a r chaeo log i s t s w ere f i nd ing i td i ff icu l t t o a s cer ta in w h ich a ge s f r om s ome s i tes w e re t o o o l d , a nd w h ich a ge s r ef lec ted t h e f i r s t a r r iva l o fp eop le i nN ew Z ea land . F o r e xamp le , o ne a r chaeo log ica l s i te o f v i ta l i mpo r tance t o N ew Z ea land p r eh is tory i sT a irua o n t h e C o romande l P en insu la , e xcava ted b y G reen a nd Smar t i nt h e e a r ly 1 960 s . T h is s i te c on ta ined a p ea r l s he l l l u re s hank o f E a s t P o lyne s ian o r ig in i n B ed 2 ( G reen 1 967 ) . T hough moa b one i nt h ed epo s i t i n d ica ted t h a t t h e o ccupa t ion w as e a r ly , a r chaeo log is t s a t t h e t ime w e r e u nab le t o a s ce r ta in w he the r i tr e p r e sen ted a n e a r ly o r l a te c o lon isa t ion e p isode . T h i s w a s b ecause t h e t wo c ha r coa l r a d ioca rbon a ge s f r om t h e d epo s i t c onf l ic ted , d e r iv ing d a te s o f 8 78 ± 4 9 ( NZ -594 ) a nd 4 43 ± 4 0 ( NZ -595 ) y ea r s B P ( Row land 1 976 :6 ) 4.

N ew Z ea land a r cha eo log i s t s w e re t h e ref o r e l ef t w i th f ew m e thod s f o r a ccu r a te ly d a t ing p r eh is to r ic d epo s i t s o u t s ide o f r ad ioca rbon d a t ing b ecause o f t h e u nava i lab i l i ty o f o t he r a b so lu te d a t ing m e thod s . T he f ew s o lu t ion s s ugge s ted b y v a r iou s r e sea rche r s t oc oun te r p rob lems a s soc ia ted w i th t h e d a t ing o fc ha rcoa l , m a r ine s h e l l o r b one w e re o f l i t t le h e lp ( s ee C hap te r 3 ) . O ne m e thod o cca s iona l ly i mp lemen ted w a s t o o b ta in w ood a nd c ha rcoa l s amp le s w h ich h ad t r ee r i ng s s t i l l p r e sen t . I tw a s b e l ieved t h a t t h e n umbe r o fr i ng s f o und i n t h e c ha rcoa l b r anch , f o r e xamp le , c ou ld p rov ide a n

T he c omb ina t ion o fo ld a nd y oung c ha rcoa l r a d ioca rbon a ge s w a s t hus d i s rup t ing t h e d iv is ion o ft h e A rcha ic a nd C la s s ic P ha ses b a sed o n a r chaeo log ica l a r tef ac t s a nd f e a tu re s , p u sh ing b a ck t h e a ppea rance o fs ome s i te s , s uch a sp a , t ot h e

5 I n bu i l ta ge m ay b ed ef ined a s" t he d if e rence i na ge b e tween t h ed ea th o f t h e s amp le a nd t h e a r cha eo log ica l e ven td a t ed . F o rw ood , i ti st h e c omb ina t ion o fg row th a g e( t he a ge o fo l d w ood i n at r ee )a nd s t o rage a ge ( t he t i me t h et r ee w a sl y ing a r ound b ef o r e i tw a s u s ed ) ." ( McFadgen e ta l . 1 994 :223 ) .

S chm id ta nd H igham ( 1998 )h ave n ow r e da t ed t h eT a i rua s i t e u s ing r e l iab le s he l lf i sh s p ec ies i d en t if ied i nt h i ss t udy . T he r e da t ing s ugge s t st h e p ea r l s he l l l u r ea r r ived i nN ew Z ea land b yt h e l a t e 1 3 th o re a r ly 1 4 th c en tu ry AD .

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3

I n t roduc t ion

CHAPTER I

H oweve r , i t s d epo s i t ion i sl o ca t ion s p ec if ic , a nd i tp rov ides o n ly ar e la t ive a ge f o rs i tes f ound a bove , o rb e low i t .

e s t ima te o f h ow m any y ea r s o f t r ee g row th h ad g one b y b ef o r e t h e w ood w a s u sed i n p r eh is to ry . A n e s t ima te w a s a l so m ade o fh ow m any o ft h e o u te rr i ng sm ay h ave d ecayed . U s ing t h is m e thod , w ood o rc ha rcoa l f r om t h e o u termo s t t r ee r i ng s w e re d a ted a nd a n e r ro r a t t r ibu ted t ot h e r a d ioca rbon a ge f o r t h e m i s s ing r i ng s . A n e xamp le o f t h is p rac t ice w a s t h e d a t ing o f Wa rehou p a b y B rod ie ( 1962 :157 159 ) . Wood f r om a p a l isade w a s i d en t if ied a s t o ta ra , t h e r i ng s c oun ted ( 90 i n t o ta l ) , a nd a d a te t a ken f r om t h e 6 0 th r i ng . T he r ad ioca rbon a ge w a s f ound t ob e 3 10 ± 6 0 y ea r s B P ( NZ -? ) , B rod ie ( 1962 :157 ) n o t ing t h a t g row th o ft h e t imbe r a f te rt h e 6 0 th r i ng c ou ld i n c rea se t h e a ge o ft h e s i t e b e tween 6 0 a nd 1 00 y ea r s ( t h is m e thod w a s a l so u sed a tT i romoana p a b y F ox ( 1978 ) ) .

T he o n ly a l terna t ive s r ema in ing f o r ap r eh is to r ian w i sh ing t o a ccu ra te ly d a te a n a r chaeo log ica l d epo s i t w hen c ha rcoa l f o r r a d ioca rbon d a t ing i sa b sen t , i st or a d ioca rbon d a te ma r ine s he l l o r b one . T he d i ff icu l ty i s , h oweve r , t h a t t h e r e l iab i l i ty o fs uch s amp le t y pe s f o r d a t ing N ew Z ea land p r eh i s to ry h a s n eve r b een s y s tema t ica l ly a nd r i go rous ly i n ve s t iga ted . C er ta in ly , m a r ine s he l l h a s b een g ene ra l ly a c cep ted b y a r chaeo log is t s a nd r ad ioca rbon l a bo ra to r ies a s r e l iab le , b u t d eba te h a s c on t inued o ve r i t s a ccu ra cy i ns ome c on tex t s ( s ee L aw 1 971 ; R af t e re ta l . 1 972 ; G ran t -T ay lo r 1 974 ; L aw 1 98 1; H igham 1 993 ; C hap te r 3 ) . T he r e l iab i l i ty o f N ew Z ea land a r chaeo log ica l b one f o r d a t ing i s a t p r e sen t p oo r ly u nde r s tood ,t hough r e sea rch i nt h ed a t ing o ff i sh b one a nd r a t b one h a s r e cen t ly b een u nder taken ( Redve r s -New ton a nd C oo te 1 994 ; R edve r s -New ton 1 9 95 ; P e tchey 1 998 ) . P e tchey 's ( 1998 ) r e sea rch h a s n ow i d en t if ied t h e f i sh s pec ie s P ag ru s a u ra tu s a nd T hyr s i te s a t un a s r e l iab le f o r r a d ioca rbon d a t ing .

O n ly a h andf u l o f r e sea r che r s s ugge s ted t h e s e lec t ion o f t w ig sw hen c hoo s ing c ha r coa l f o rd a t ing , b u t t h e i mpo r tance o f s pec ie s s e lec t ion w a s n o t d i scus sed ( Law 1 97 1 ; G ran t T ay lo r 1 974 ; s e e C hap te r 3 ) . A rchaeo log i s t s w e re a dv i sed w hen d a t ing m a r ine s he l l t o a vo id d a t ing m ud sna i l ( Amph ibo la c r ena ta ) , b u t e xpe r imen t s o n r e l iab i l i ty l a rge ly f o cused o n d a t ing t h e c a rbona te o r k e ra t in f r ac t ions o fs he l l , r a the rt h an r i go rous i n ve s t iga t ion o fr e l iab le s he l lf i sh s pec ie s ( T ro t te r 1 967a : 138 ) .

T he r e l iab i l i ty o fm a r ine s he l l i sp robab ly o f mo re c once rn t o a r chaeo log i s t s t h an b one i n v i ew o f i t s f r equen t u se f o r r a d ioca rbon d a t ing N ew Z ea land p r eh i s to ry s i nce t h e m id 1 950 s . T h is i se spec ia l ly t r ue i n t h e d a t ing o f p a r t icu la r a r chaeo log ica l s i te s s uch a s p a w h ich o f ten l a ck d a tab le c ha rcoa l . F o rp a , 5 5% o fr ad ioca rbon d a te s a r e f r om m a r ine s he l l , w i th 9 0% o fp a d a ted s i nce 1 9 76 u s ing t h i s s amp le t ype ( Schm id t 1 993 , 1 996a ) . I n a dd i t ion , t h e mo s t c ommon m a te r ia l f r om N ew Z ea land a r chaeo log ica l s i te s d a ted b y t he U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra to ry h a s b een m a r ine s he l l , mak ing u p 7 9% o f p reh is to r ic d a tes ( H igham p e r s . c omm . ) .

H oweve r , i n1 968 ,t h e a r chaeo log is t B .F . L each s ugge s ted t o t h e N ew Z ea land A rchaeo log ica l A s soc ia t ion t h a t w ide r s c reen ing o f s amp les s ubm i t ted f o r d a t ing a r chaeo log ica l s i te s w a s r equ i red s o r e l iab le ma te r ia l s c ou ld b e i s o la ted ( Leach p e r s . c omm . ) . T hen i n 1 976 , as o lu t ion t o t h e p rob lems o f d a t ing c ha r coa l s amp le s w a s f o rmu la ted b y L each a nd a b o tan is t , B . Mo l loy ( Leach p e r s . c omm . ; s e e C hap te r3 ;A nde r son a nd McGove rn -W i l son 1 990 ; A nde r son 1 99 1) . T he s o lu t ion w a s t o i n fo rm a r chaeo log is t s t h a t a l c ha r coa l a nd w ood s amp le s s ubm i t ted f o rr a d ioca rbon d a t ing s hou ld b e i d en t if i ed t ot w ig s o fs hor t l ived s p ec ie s , s o a st o r educe t h e r i sk o fi n bu i l t a ge . S i nce t h is t i me , a r chaeo log i s t s h ave s e n tc ha r coa la nd wood s amp le st ob e i d en t if ied p r io rt o d a t ing . T h is w a s i n i t ia l ly u nder taken b y B . Mo l loy o f t h e U n ive r s i ty o f C an te rbu ry , a nd n ow b y R . Wa l lace o f t h e U n ive r s i ty o f A uck land D epa r tmen t o f A n th ropo logy . T h i s s o lu t ion h a s s i gn if ican t ly i mp roved t h e a c cu racy o fc ha r coa l a ge s ( s ee H igham 1 993) , a nd c ha rcoa l i d en t if ied u s ing t h is i n i t ia l s c reen ing p roces s i sb e l ieved b y m any a r chaeo log is t s t oday a s p rov id ing s amp le s f o r d a t ing w h ich s hou ld y i e ld a ccu ra te a ges ( t hough d eba te s t i l l c on t inue s o ve r c ha r coa l 's r e l iab i l i ty )( s ee A nde r son 1 99 1; C hap te r3 ) .

A I MS OF TH IS STUDY T he a im o ft h i s s t udy i st oi n ve s t iga te t h eu se o fm a r ine s he l l f o r r a d ioca rbon d a t ing N ew Z ea land p r eh is to ry . T h i s s t udy w i l l t h e ref o re e va lua te :

B u t w ha t a bou t d a t ing a r chaeo log ica l s i t e s w he re c ha r coa l a nd w ood s amp le s a r e a b sen t , o r w he re i ti sd i ff icu l t t o o b ta in d a tab le c ha rcoa l? I nt h i s r ega rd , a r chaeo log is t s s i nce 1 976 h ave e i the r c ons ide red a l terna t ive c a rbon -con ta in ing ma te r ia ls t o r a d ioca rbon d a te , o r s ough t o t he r a b so lu te c h rono log ica lm e thod st od e te rm ine t h ea ge o f as i te . T he u se o f o b s id ian h yd ra t ion h a s a ga in b een a dd re s sed f o r d a t ing , b u t d eve lopmen to ft h is t e chn ique i sa ta ne a r ly s t age i nN ew Z ea land ( s ee S u t ton a nd S hepa rd 1 994 ; S hepa rd e ta l . 1 996 ; S t evenson e t a l . 1 996 ) , a nd r ad ioca rbon a ge s a r e s t i l l r equ i r ed a s ac heck o n t h e o b s id ian h yd ra t ion c h rono logy . T he K aha roa A sh h a s n ow b een f i rm ly d a ted t o 6 65 ± 2 0 y ea r s B P( H igham p e r s . c omm . 6)a nd c an b e u sed e f f ec t ive ly a s ac h rono log ica l ma rke r f o r N ew Z ea land p r eh i s to ry . D r . T .F .G . H igham , U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra to ry .

6

4

1 )

t h er ep roduc ib i l i ty o fr a d ioca rbon d a tes b e tween s he l lf i sh s pec ie s c ommon ly f ound i nN ew Z ea land a r chaeo log ica l s i te s . I ti sp os s ib le t h a ts ome m a r ine s he l l s pec ie s w i l l n o tp roduce c ons i s ten t ly r e l iab le r a d ioca rbon a ge s . B y i d en t if y ing r e l iab le s he l lf i sh s pec ie st od a te ,N ew Z ea land a r chaeo log is t s w i l l b ea b le t oc onf iden t ly s e lec tp a r t icu la rs h e l lf i sh s pec ie sf o r d a t ing p u rpo se s ;

2 )

t h e c h rono log ica l a g reemen tb e twe en c a l ib ra ted m a r ine s he l l a nd c ha rcoa l r ad ioca rbon d a t e sf r om c on tempo ra ry a r chaeo log ica ld epo s i t s . B o th m a r ine s he l l a nd c ha r coa l r a d ioca rbon a ge s f r om ac on tempo ra ry a r chaeo log ica l d epo s i ts hou ld a g ree i nd a t ing ap r eh i s to r ic e ven t . H oweve r , t h i sm ay b e d ependan to ns u i tab le s he l lf i sh s pec ie s d a ted , i n bu i l ta ge o fc ha r coa l ,o rt h em a r ine s he l l c a l ib ra t ion m e thod e mp loyed ( s ee C hap te r s 4a nd 5 ) ;

3 )

v a r iab i l i ty i nc ha rcoa l a ge s . C ha r coa l r a d ioca rbon a ges m ay b e l e s sr e p roduc ib le t h an m a r ine s he l l d a te s( d ue t o f a c to r s s uch a si n bu i l ta ge ) , a nd s ol e s sd es i rab le t o c ho se a s ad a t ing m ed ium f o rt h ea r chaeo log is t ;

4 )

t h ee f f ec to fh a rd w a te ro nt h e d a t ing o fN ew Z ea land a r chaeo log ica l m a r ine s he l ls . S t ra ta c on ta in ing a nc ien t c a rbon a r ee x tens ive i nN ew Z ea land ,t h e ref o re t h e

I n t roduc t ion

CHAPTER 1

h a rdwa te re f f ec t i s ac once r nt op r eh i s to r ians w hen d a t ing a r chaeo log ica l s i t e s i ns u ch a r ea s ; 5 )

6 )

v ege ta t ion t ype s u r round ing t h e a r chaeo log ica l s i te s d u r ing o ccupa t ion i s a l so e xam ined t o p rov ide i n f o rma t ion r e ga rd ing t h e f u e l s ou r ce s w h ich w e re a va i lab le i n p r eh is to ry . T h is i n f o rma t ion m ay e xp la in v a r ia t ion s i n c ha rcoa l r a d ioca rbon a ge sd ue t of a c to r s s uch a si n bu i l ta ge .

t h e a pp l icab i l i ty o ft h e S t u ive ra nd B ecke r( 1993 ) mode l led m a r ine c a l ib ra t ion c urve t oN ew Z ea land p reh i s to ry . T he re a r et wo m e thod sb yw h ich m a r ine s he l lr a d ioca rbon d a te s m ay b ec a l ib r a ted ( s ee C hap te r 5 ) . A n i n ve s t iga t ion o ft h ea pp l icab i l i ty o ft h e S tu ive r a nd B ecke r( 1993) mode l led m a r ine c ur ve i si mpo r tan t f o rp r eh i s to r ians , a sc ho ice o ft h i sc a l ib ra t ion m e thod may e f f ec tt h ea ccu racy o fd a t ing a na r chaeo log ica l d epo s i t ;

I nC hap te r7 ,a n a na ly s is o ft h e p a i red r a d ioca rbon a ge s f r om t h e s i te s e xcava ted f o r t h i s d i s se r ta t ion i s u nde r taken . A rchaeo log ica l s i te s w he re c a l ib ra ted m a r ine s he l l a nd c ha rcoa l r a d ioca rbon d a te s a r e i na g reemen t a r e d i scu s sed , a nd r e a sons f o r d i sc repanc ie s b e tween m a r ine s he l l a nd r a d ioca rbon a ge s f r om o t he rs i t e sa r e p ropo sed . I nC hap te r 8 , t h e o ve ra l l r e su l t s f r om t h e s t udy a r e e va lua ted , d r aw ing c onc lus ion s o n t h e u se o fm a r ine s he l l f o rr a d ioca rbon d a t ing N ew Z ea land p reh is to ry , t h e a dvan tage s a nd d i sadvan tage s o fu s ing s he l l c ompa red t oc ha r coa l , a nd t h e e f f ec t o fu s ing e i the ro ft h e c ur ren t ly e mp loyed m a r ine c a l ib ra t ion c u rve s .

t h ec u r ren t AR v a lue f o rN ew Z ea land ( H igham a nd Hogg 1 995 ) . T he mode l led m a r ine c a l ib ra t ion c u rve d epend su pon t h e l o ca l r e se rvo i rc o r rec t ion ( AR )b e ing n on t ime d ependan t( s ee C hap te r5 ) . I fi ti ss hown f r om t h is r e sea r ch t h a t AR m ay v a ry t h rough t i me ,t h en u se o f t h ec u r r en tv a lue f o rc a l ib ra t ing a l N ew Z ea land p reh is to r ic m a r ine s he l la ge sm ay b e i n va l id .

T he i n ves t iga t ion o f t h e se v a r iab le s w i l l h ave i mp l ica t ion s f o r c e r ta in c r i t ica l i s sue s i nN ew Z ea land a r chaeo logy , s uch a st h e d a t eo fc o lon isa t ion b a sed o n a r chaeo log ica l s i te s w i th b o th c ha r coa la nd ma r ine s he l lr a d ioca rbon c h rono log ie s . U nde r s tand ing t h e p r inc ip le s b eh ind r a d ioca rbon d a t ing i s i mpo r tan t i n u nder tak ing t h i s i n ve s t iga t ion . T h is i s t h e s ub jec t o fC hap te r 2o ft h is s t udy . T h i s c hap te r a l so e xp la in s t h e r ad io ca rbon d a t ing t e chn ique u s ed a tt h e U n ive r s i ty o f Wa ika to l a bo ra to ry , a s w e l l a s s t a t i s t ica l a nd c a l ib ra t ion m e thod s e mp loyed i n t h e a na ly s i s o f a r chaeo log ica l r ad ioca rbon a ge s . C hap te r 3c omp r ise s ah i s to r ica l r e v iew o ft h e o p in ion s o f a r chaeo log i s t s a nd r a d ioca rbon d a t ing r e sea r che r s o n t h e c ho ice o f m a te r ia ls f o r r a d ioca rbon d a t ing N ew Z ea land p reh is tory . Many v i ew s o n t h i s i sue a r e p r e sen ted , a s w e l l a s s t ud ie s u nder taken o ve r t h e y ea r s b y a r chaeo log i s t s a nd r ad ioca rbon d a t ing l a bo ra to r ie s c ompa r ing a ge s b e tween d i f f e r ing s amp le t ype s . As o lu t ion t ot h i s s amp le t ype i s sue i s p ropo sed . C hap te r 4 i d en t if ie s p rob lem s a s soc ia ted w i th t h e r ad ioca rbon d a t ing o fc ha r coa l a nd m a r ine s h e l l w h ich m ay c ause d i s c r epanc ie s b e tween r a d ioca rbon a ge s o n t h e se t wo s amp le t y pe s . I n C hap te r 5 ,b o th m e thod s b y w h ich m a r ine s he l l r a d ioca rbon a ge s c an b e c a l ib ra ted t o y ea r s AD a r e e xp la ined a nd s c ru t in ised . T h i s i su nder taken t o a s cer ta in whe the r e i the r ma r ine s he l l c a l ib ra t ion m e thod a f f ec t s t h e p lacemen to fa n a r chaeo log ica le ven ti nc a lenda rt ime . C hap te r 6d e sc r ibe s t h e a r cha eo log ica l s i te s e xcava ted f o r t h is d i s s e r ta t ion t o o b ta in c ha r coa l /ma r ine s he l l p a i r s . T he s i tes w e r e c ho sen t o p rov ide ac r o s s sec t ion o ft h e m a r ine a nd t e r r e s t r ia l e nv i ronmen t s a s soc ia ted w i th a r chaeo log ica l s i te s a r ound N ew Z ea land . T hey w e re a l so s e lec ted a cco rd ing t ot h e l a rge v a r ie ty o fs h e l lf i sh s pec ie s p re sen t , t o e nab le v a r ia t ions i nr a d ioca rbon d a te s o n p a r t icu la r s he l lf ish s pec ies t ob e i nve s t iga ted . D a ta o n t h e a r t if a c tua l a nd f a una l ma te r ia l r e cove red , s t ra t ig raphy , s i t e h i s to ry , s u r round ing g eo logy , a nd t h e e nv i ronmen t a s soc ia ted w i th t h e s i te s d u r ing t h e i r f o rma t ion i sp r e sen t ed . T h is i n f o rma t ion i sv i ta l a s t h e e f f ec t o f e nv i ronmen t a nd h ab i ta t s o f N ew Z ea land s he l lf i sh s p ec ies o n t h e d a t ing o fm a r ine s he l l h ave s e ldom b een r i go rous ly i n ve s t iga ted . R econ s t ruc t ion o f t h e

5

CHAPTER 1

I n t roduc t ion

6

CHAPTER 2

THE RAD IOCARBON METHOD " Po ten t ia l ly m o re s en s i t ive i s an ew m e thod o fd a t ing o rgan ic ma te r ia lb ym ean s o fi t sr ad ioca rbon c on ten t . T h i sm e thod , a b y -p rod uc to fa tom ic r e search , . . .m ay e ven tua l ly e nab le s pec imen s u p t o4 0 ,000 y ear so ld t ob ed a ted o b jec t ive ly ." S i r Mor t ime r W hee ler ( 1954 :50 )

T he ' 4C p roduced i sr ap id ly o x id i sed t of o rm c a rbon d i ox ide ( C O 2 ) . T he ' 40 3 , i s t h en t a ken i n b y p l an t s t h rough p ho to syn the s is w he re i te n t e r s t h e t e r r e s t r ia l f ood c ha in , a nd b y d i rec t e xchange w i th t h e o cean w he re i ti si n co rpo ra ted i n to o cean ic o rgan isms ( F igu r e 2 . 1) . A f te r p roduc t ion , 1 4C b eg in st od ecay a cco rd ing t ot h ep roce s s :

I NTRODUCT ION

1 4

T h i s c hap te r e xp la ins t h e b a s is o f t h e r a d ioca rbon d a t ing m e thod b y w h ich a bso lu te d a te s h ave b een o b ta ined f r om a r chaeo log ica l s i te s t h roughou t t h e w o r ld . T he r a d ioca rbon d a t ing t e chn ique emp loyed a t t h e U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra to ry t o d a te N ew Z ea land p r eh i s to ry i s a l so d e sc r ibed . A dd i t iona l ly , t h e s t a t i s t ica l m e thodo logy a nd c a l ib ra t ion p rocedu r e s u sed i nt h i s s t udy a r ep re sen ted .

1 4C >

w he r e ßi s ab e ta p a r t ic le e m i t ted a s ap roduc t o fr a d ioa c t ive d ecay . When t h e p roduc t ion a nd d ecay o f ' 4C i s i n e qu i l ib r ium , t h e re i s ac on s tan t c oncen t ra t ion o f ' 4C i ne ach c a rbon r e servo i r a nd t h u s i nt h e a s soc ia ted l i v ing o rgan i sms ( Bowman 1 990 :10 ; A i tken 1 990 :57 -58 ) . When a n o rgan i sm d i e s , i t n o l o nge r e xchang e s c a rbon w i th i t s p a r t icu la r r e se rvo i r a nd t h e ref o re t h e r ema in ing ' 4C i n t h e p l an t o r a n ima l d ecay s w i thou t r e p len i shmen t a cco rd ing t o ak nown r a te . T he r a te o fr a d ioac t ive d ecay i sc a l led t h e h a lf l if e . F o r ' 4C , t h is m ean s t h a t a f te r 568 y ea r s , h a lf o f t h e o r ig ina l a moun to f' 4C w ou ld r ema in i n ad ead o rgan ism ( F igu re 2 . 2 ) .

PR INC IPLES AND ASSU MPT IONS C a rbon o c cu r s i nn a tu re a s t h ree i s o tope s : DC a nd ' 4C . P ropor t iona l ly , ' 2C m ake s u p c a . 9 9% o fc a rbon , ' 3C c a . 1 % a nd ' 4C c a . 1x 1 4C i sf o rmed c on t inua l ly i nt h e l owe r s t ra to sphe r e a nd u ppe r t r opo sphe re b y t h e i n te rac t ion o f n eu t ron s p r oduced b y c o sm ic r a y s w i th n i t rogen a t oms ( Bowman 1 990 ) : 1 4

N + In— >

C

' 4N + ß—

IH

A TMOSPHERE -2 %

1

[ MAR INE]

[ TERRESTR IAL]

( ORGAN IC)

B IOSPHERE

B IOSPHERE

%

-0 .0 1 %

_

( INORGAN IC )

S URFACE WATER ( M IXED L AYER) -2 %

A

w NONL IV ING ORGAN IC MATTER ( HUMUS ) -5 %

D ISSOLVED ORGAN IC MATTER -2 %

DEEP WATER 2 1-

S ED IMENTS -4 %

-83 %

1

r

F i gu re 2 . 1 . C a rbon r e se rvo i r si nn a t u r e( %=%Ca rbon )( f rom T ay lo r 1 987 :8 ) .

7

T he R ad ioca rbon Me thod

CHAPTER 2

1 T he d ecay o f ar ad ioca t ive e l emen t f o l lows t he e xponen t ia l d ecay l aw . T he p r imary c ha rac te r is t ic o fe xponen t ia l d ecay i s t ha tt he p e rcen tage d ec rease i nn umbe ro f a toms p e ru n i tt ime i sc ons tan t ; h ence a f te r e ach h a l f l i fe t he n umbe ro fa toms r ema in ing i sh a lved : i ft here a re Ao a to ms t ob eg in w i th , t hen a f te ro ne h a l f l i fe t here w i l lb e A0/ 2 a toms r ema in ing ; a f ter t wo h a l f l ives , A0/ 4 r ema in ; a f te rt h ree , A0/ 8a nd s oo n .

F igure 2 . 2 . T he h a lf l if e o f

1 4C ( f rom

B owman 1 990 :11) .

T he h a lf l if e o f' 4C w a s o r ig ina l ly c a lcu la ted b y L ibby e ta l . ( 1949 )a s5 568 y ea r s ( known a st h e " L ibby " h a lf l if e ) .

t h is , r a d ioca rbon d a te s c ou ld c onve r ted t oc a lenda ra ge s .

L a te r m ea su remen t s i n c r ea sed t h is t o5 730 y ea r s ( c a l led t h e " Camb r idge" o rN ew H a lf -L if e ) ( Tay lo r 1 987 :9 ) . Af t e r 5 0 6 0K y ea r s , v e ry l i t t le 1 4C r ema in s , a nd t h e ref o r e t h i s b ecome s a m ax imum a ge t o w h ich t h is c h rono log ica l t e chn ique e x tend s . ( I n p r ac t ice , h oweve r , 4 0K y ea r s B P i s s e ldom e xceeded i n a r chaeo logy ( s ee A l len a nd H o ldaway 1 995 :10 1112 ) ) . I t i s f r om t h is p roce s s o f d ecay a nd k now ledge o ft h eh a lf l if e o f 4C , t h a tw e may f i nd t h e a ge o f a n o rgan ism .

C a l ib ra t ion c urve s w e re t h e ref o re d eve loped i n t h e e a r ly 1 970 s t o d e r ive c a lenda r a ges f r om r a d ioca rbon d a t e s ( s ee S ue s s 1 967 , 1 970 ; D amon e t a l . 1 972 ; A i tken 1 990 :3 ) . B ecau se t r ee r i ng s a r e r e p resen ta t ive o f e ven t s o f k nown h i s to r ic a ge , r a d ioca rbon m ea suremen t s o f s ucce s s ive r i ng s a lowed f o rc o r rec t ion o ff l uc tua t ing ' 4C l e ve ls t h rough t ime . T h is p roce s s t h us p roduced a c a l ib ra t ion c u rve t oc onver t a r a d ioca rbon a ge d i rec t ly t o ac a lenda r d a te ( F igu r e 2 . 3 ) . T he se c a l ib ra t ion c u rve s w e re a pp l icab le f o r r a d ioca rbon d a te s d e r ived f r om c ha r coa l a nd w ood s amp le s , b u t n o t f o r s amp le s f o rmed i nt h e o cean s uch a s m a r ine s he l l . I tw a s f ound t h a t m a r ine s he l l r a d ioca rbon a ge s w e r e c a . 4 00 y ea r s o l de r t h an c ha r coa l o r w ood r ad ioca rbon d a te s o ft h e s ame c a lenda r a ge ( s ee C hap te r 5 ) . T h is w a s b ecau se t h e o cean r e se rvo i r e xpe r ience s s l ow m ix ing a nd a b so rp t ion o f a tmo sphe r ic 1 4C . T he ref o re , b ef o re r a d ioca rbon d a te s o n m a r ine s he l l c ou ld b e a pp l ied t o ac a l ib r a t ion c u rve t od e r ive ac a lenda r a ge , c a . 4 00 y ea r s f i r s t h ad t ob e s ub t rac ted . T h is a ge d i f f e rence w a st e rmed t h e R eservo i rC o r rec t ion o r R( s ee C hap te r5 ) .

U s ing ' 4C a s ad a t ing t e chn ique d epend s o n an umbe r o f a s sump t ions . T he se a r e ( Tay lo r 1 987 :3 ) : 1 . T he c oncen t ra t ion o f ' 4C i ne ach c a rbon r e se rvo i r h a s r ema ined e s sen t ia l ly c on s tan to ve rt h e ' 4C t ime s c a le ; 2 .

3 .

t h e re h a s b een c omp le te a nd r a p id m ix ing t h roughou t t h e v a r ious c a rbon r e se rvo i r s w o r ldw ide b a s is ;

of

o n

1 4c

a

n o t

a lway s

b e

d i rec t ly

c a rbon i s o tope r a t io s i ns amp le s h ave n o t b een a l te r ed e xcep t b y 4C d ecay s i nce t h e se s amp le m a te r ia l s c ea sed t o b e a n a c t ive p a r t o f o ne o f t h e c a rbon r e se rvo i r s( a sa tt h e d ea th o fa no rgan ism ) ;

WA IKATO LABORATORY

4 .

t h eh a lf l if eo f' 4C i sa ccu ra te ly k nown ; a nd

S amp le P re trea tmen t

5 .

n a tu ra l l e ve l s o f ' 4C c an b e m ea su red t o a pp rop r ia te l e ve l so fa ccu racy a nd p rec is ion ."

H igham ( 1993 :98 119 ) u nder took e x ten s ive s t ud ie s o n t h e p re t rea tmen to fN ew Z ea land a r chaeo log ica l s amp le sp r io rt o r ad ioca rbon d a t ing . H e c onc luded t h a t , " A t t h e l e ve l o f p rec i s ion u sed i n t h e e xamp les g iven a bove , c on tam inan t s a r e e i the r n eg l ig ib le i nt h e i r i mpac t , o rt h e i r s i de e f f ec t s a r e b e ing m a sked b y h ighe r s t anda rd e r ro r s . G iven t h e s i tua t ion e ncoun te red a tP l ea san t R ive r i ti sw ise t oe r r o n t h e s i de o f c au t ion a nd p r e t rea t a l l a r chaeo log ica l s amp le s w i th s imp le r ou t ine p rocedu r es ." ( H igham 1 993 :119 ) . F o r t h i s s t udy , p r e t rea tmen t p r ocedu re s w e re d eve loped f o r c ha r coa l a nd ma r ine s he l l f o l low ing t ho se o fH igham ( 1 993 :98 119 ; p e r s . c omm . ) , i n c lud ing t h e r emova l o f p hy s ica l a nd c hem ica l c on tam inan t s a nd , f o r m a r ine s he l l , t h e u s e o fX ray p owde r d i f f rac t ion ( XRD )a na ly s is t ot e s t f o rr e c ry s ta l l isa t ion .

RAD IOCARBON DAT ING AT THE UN IVERS ITY OF

T he f i r s t t e s t o ft h e r ad ioca rbon m e thod w a s c a r r ied o u t b y A rno ld a nd L ibby i n 1 949 ( A i tken 1 990 :58 ) . H e r e r a d ioca rbon a ge s o f w ood t a ken f r om E gyp t ian t omb s o f k nown a ge w e r e c ompa r ed . Many o f t h e r ad ioca rbon a nd h i s to r ic a ge s w e r e i n c l o se a g reemen t i lus t ra t ing t h a t t h e r a d ioca rbon d a t ing me thod w a s av e ry a ccu ra te a nd p r ec ise t o o l f o r a r chaeo log ica l r e sea rch . H oweve r , i tw a s o b se rved e a r ly o n i n r a d ioca rbon d a t ing t h a t t h e p roduc t ion a nd movemen t o f 1 4C i nt h e a tmo sphe r e h ave n o t b een c on s tan t t h rough t ime ( d e V i res 1 958 ; W i l l i s e ta l . 1 960 ) . B ecau se o f

8

CHAPTER 2

T he R ad ioca rbon Me thod

F igu re 2 . 3 . R e la t ion sh ip b e tween r a d ioca rbon a ge s a nd c a lenda r d a te s d e r ived t h rough t h e d a t ing o ft r ee r i ng s . C u rve ss u ch a st h is a r eu sed i nt h ec onve r s ion o f ar a d ioca rbon a ge t o ac a lenda rd a te ( f rom A i tken 1 990 :99 ) .

( Hogg 1 982 :26 ; G up ta a nd P o la ch 1 985 :11 , 1 28 ) . A ragon i te s e c re t ing s he l lf i sh s pec ie s t y p ica l ly u s ed i n r a d ioca rbon d a t ing N ew Z ea land p reh is to ry i n c lude P aph ie s a u s t ra l i s ( p ip i ) , P aph ie s s ub t r iangu la tum ( t ua tua ) , A u s t rovenus s t u tchbury i ( c ock le ) , C om ine l la s p . ( whe lk s ) ,V enerup i s l a rg i l le r t i ( ob long c ock le ) , My t i lu s e d i t / i s a o teanu s ( b lue mu s se l ) , P e rna c ana l icu la ( g r een m u s se l ) a nd L une l la s ma ragda ( c a t seye ) . A n XRD a na ly s is o ft h e se s pec ie s w i l l t yp ica l ly s how t h e p r esence o fa r agon i te o n ly , b u t i fc a lc i te i s d e tec ted , r e cry s ta l l isa t ion h a s o ccur red a nd t h e m a r ine s he l l i sr e jec ted f o r d a t ing . C a lc i te s e c re t ing o rgan isms s uch a s C ra s so s t rea g lomera ta ( r ock o y s te r ) a r e n o t X rayed a s r e cry s ta l l i sa t ion i su nde tec tab le .

C on tam inan t s o f c once rn f o r c ha r coa l s amp le s m ay b e d e r ived f r om p r e - a nd p o s t -samp l ing s ou r ce s . C on tam ina t ion a f te r d epo s i t ion i n c lude s r oo t i nf i l t ra t ion f r om p l an t s g row ing a bove t h e s i te , h um ic a c id a b so rp t ion f r om u ppe r l e ve l d ecompo sed p l an t r ema ins i n t r ud ing d own o n to t h e s amp le , a nd a d sorp t ion o f c a rbona te s f r om g round w a te r f l ow ing t h rough t h e s i te ( Hogg 1 982 :18 ; H igham 1 993 :103 ) . T he f i r s tt wo c on tam inan t sw i l l m ake t h ec ha r coa l a ppea rt o o y oung w hen d a ted , wh i ls tc a rbona te c on tam ina t ion c an c au se c ha rcoa l a ge s t o a ppea r t o o o l d . S ou r ce s o f c on tam inan t s a f t e r s amp le r e covery c an b e f r om p ackag ing o ft h e s amp le u s ing p ape r p roduc t s , f r om h a i r , c i ga r e t te a s h ( mak ing t h e d a tes mo r e mode rn ) , a nd o i l o rg r ea se ( mak ing t h e d a te s t oo o l d )( Hogg 1 982 :2 1) .

C on tam ina t ion b y o lde r c a rbon i s m o r e s e r iou s t h an c on tam ina t ion b y moder n c a rbon f o r N ew Z ea land a r chaeo log ica l m a te r ia ls b ecause o f t h e i r y oung a ge ( Tab le 2 . 1) . C augh ley ( 1988 :246 ) n o te s t h a t f o r as amp le 9 00 y ea r s o l d , c on tam ina t ion b y 1% moder n c a rbon w i l l r e duce t h e t r ue a ge o f t h e s amp le b y a pp rox ima te ly t h e s ame p e r cen tage . H oweve r , f o r e ve ry 1 % o f o ld c a rbon c on tam ina t ion , t h e re i s ac a . 9% e r ro r ( ca . 8 0 y ea r s ) . T he ref o r e f o r N ew Z ea land p r eh is to ry , w e s hou ld b e mo re c oncer ned a bou t c on tam ina t ion f r om o l d c a rbon s ou rce st han f r om m oder n .

A s m en t ioned a bove , r e c ry s ta l l i sa t ion o f s he l l a f t e r d epos i t ion i n a n a r chaeo log ica l c on tex t m u s t b e t e s ted f o r , e ven t h ough w i th t h e s hor t l e ng th o fN ew Z ea land p r eh is to ry t h is s i tua t ion s e ems u n l ike ly . H igham h a s n o ted t h a t , " No N ew Z ea land a r chaeo log ica l s he l l s h ave e ve rb een i d en t if ied a s c on tam ina ted b y r e c ry s ta l l isa t ion , s o XRD [ X ray d i f f rac t ion a na ly s is ] i sn o t r o u t ine ly i mp lemen ted "7 ( H igham 1 993 :99 ) . R ec rys ta l l isa t ion o f m a r ine s h e l l i n vo lve s t h e d i s so lu t ion o f t h e s he l l a nd r e c ry s ta l l i sa t ion o f c a lc ium c a rbona te i nt h e f o rm o f c a lc i te . T h i s p r o ce s s c an o n ly b e d e tec t ed i n a r agon i te -sec re t ing o rgan i sm s . I t c au se s a r a d ioca rbon a ge t o b e t oo y oung , a s t h e r e c ry s ta l l isa t ion p roce s s i n co rpo ra te s mode rn c a rbon i n to t h e s he l l s t ruc tu re 8

Charcoa l P re trea t ment T hough H igham ( 1993 :119 ) f ound t h a t t r ea ted a nd u n t rea ted c ha rcoa l s amp le s f r om h i s s i te s s howed n o s i gn if ican t d i f f e r ence i n t h e i r t r ue r a d ioca rbon a ge , a r ou t ine p r e t rea tmen tp rocedu re w a s u nder taken f o rt h i s d i s se r ta t ion

A nde r son e ta l . ( 1996 :66 ) h ave n o t ed t h a t as amp le o fp aua ( Ha l io t i si r s ) f r om t h e S hag Mou th m oa -hun t ing s i t ew a s p o s s ib ly a f f ec t ed b y r e c rys ta l l i sa t ion . 7

G up ta a nd P o lach ( 1985 :128 ) n o te t h a tu nde rp a r t icu la re nv i ronmen ta l c ond i t ion s ,r e c ry s ta l l isa t ion m ay s ome t ime s c au se s h e l l a g e st oa ppea rt o o o l d . 8

9

T he R ad ioca rbon Me thod

CHAPTER 2

% c on tam ina t ion w i th MODERN c arbon 0%

1 %

5%

1 0%

2 5%

5 0%

E s tA ge B P .

9 00

8 90

8 50

8 10

6 70

4 40

% e rror

0

1

5

1I

2 6

5 1

% c on tam ina t ion w i th OLD c arbon 0%

1 %

5%

1 0%

2 5%

5 0%

E s tA ge B P .

9 00

9 80

1 320

1 770

3 280

6 630

% e rror

0

9

4 7

9 7

2 64

6 37

T ab le 2 . 1 . T he e f f ec t o n a9 00 y ea r s o ld s amp le w hen c on tam ina ted b y d if f e r 'ng a moun t s o f modern a nd o l d c a rbon ( f rom C augh ley 1 988 :247 ) . t o r emove o bv ious c on tam inan t s s uch a s r oo t h a i r s a nd c a rbona te sf r om c ha rcoa l s amp le s .

s amp le i n to CO , f o r t h e m ea su r ing o f ' 4C a c t iv i ty . I nL iqu id S c in t i l la t ion ( LS ) C oun t ing , as amp le w a s c onve r ted i n to b enzene ( C ,H , ) , a nd t h en a s c in t i l la to r a dded . As c in t i l la to r i s ac ompound w h ich r e ac t s f l uo re scen t ly t ot h e e m i s s ion o f r a d ioac t ive p a r t ic le s b y p roduc ing s ho r t b u r s t s o f p ho ton s ( Tay lo r 1 988 :86 -88 ; P o lach 1 992 :199 ) . B ecau se o f t h is

T he c ha r coa l s amp le w a s f i r s t s c reened f o r p hy s ica l c on tam inan t s s uch a s r oo t h a i r s , s and a nd p i ece s o f s he l l . T he s amp le w a s t h en c a ref u l ly c r u shed u s ing a mor ta r a nd p e s t le t o r e vea l a ny a dd i t iona l c on tam inan t s m is sed d u r ing i n i t ia l s c reen ing , a nd t oe xpo se a s much o ft h e s u rf ace a r ea a sp o s s ib le t oc hem ica l p r e t r ea tmen t . T he c ha rcoa l w a s t h en w a shed w i th h o t 1 0 % HC 1 f o r 2 4 h ou r s t o r emove c a rbona te s , t h en r i nsed w i th d e ion ised w a te r t o a ch ieve a n eu t ra l p H l e ve l , a nd a ga in s c reened f o r a ny p hy s ica l c on tam inan t s . T he c ha r coa l w a s t h en d r ied i n a n o ven a t

a b i l i ty , t h e e m i ss ion o f ßp ar t ic le s t h rough t h e r a d ioac t ive d ecay o f ' 4C c an b e d e tec ted a nd t h e r ef o re c oun ted t o d e term ine ' 4C a c t iv i ty . B enzene w a s i d ea l f o r L S c oun t ing b ecau se o f i t s h igh f r a c t ion o f c a rbon a nd e xce l len t l i gh t t r ansm is s ion q ua l i t ie s . L S C oun t ing b ecame w ide sp read i n t h e 1 960 s , t h e f i r s t c omme rc ia l l i qu id s c in t i l la t ion c oun te r b e ing b u i l t a s e a r ly a s 1 953 ( Tay lo r 1 987 :76 ,77 ,86 ; P o lach 1 992 :199 ) . T he a dvan tage s o ft h e se t e chn ique s o ve rt h e s o l id c a rbon c oun te r w a s t h a t t h e max imum d a t ing r a nge w a s i n c rea sed a s w a s c oun t ing p rec is ion , l e s s s amp le w a s r e qu i red , a nd r ep roduc ib i l i ty w a s i mp roved ( Tay lo r 1 987 :83) .

8 0 °C . Mar ine S he l l P re trea t ment B ef o r e am a r ine s he l l s amp le c ou ld b e d a ted , It e s ted e ach s h e l l f o r r e c ry s ta l l isa t ion b y XRD u s ing aP h i l ip s PW 1 729 X ray g ene ra to r . T he s he l l s amp le w a s f i r s t c l eaned i n a n u l t ra son ic b a th f o r 1 5 m inu te s t or emove a ny a dhe red d eb r i s , a nd t h en l e f t i na n o ven o ver n igh t t od ry . As ma l l p or t ion o f s h e l l w a s t h en r emoved f r om e ach s he l l i nt h e s amp le , t h e p i ece sc omb ined , a nd t h en g round u s ing amor ta r a nd p e s t le . T he g round s he l l w a s t h en X rayed . N o a r agon i t ic m a r ine s h e l ls r a d ioca rbon d a ted i nt h is s t udy s howed e v idence o f r e c ry s ta lI i s a t ion .

T he f our th t e chn ique , A cce le ra ted Ma s s S pec t rome t ry ( A MS ) , w a s d eve loped i nt h e l a te 1 970 s ( Tay lo r 1 987 :90 ) . Wh i le t h e p r ev ious t e chn iques m ea su re t h e ' 4C r a d ioa c t iv i ty o f as amp le t h rough d e tec t ion o f b e ta p a r t ic le e m i s s ion s , AMS a c tua l ly c oun t s t h e n umbe r o f ' 4C a t oms i n as amp le . T hough o n ly v e ry s ma l l s amp le s a r e r e qu i r ed f o r t h i s t e chn ique , i ti se xpen s ive i nc ompa r i son t o ßd ecay m e thod s . T he U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra to ry o b ta ins r a d ioca rbon d a te s b y L S c oun t ing o f b enzene . F o r t h i s t h e s i s , Ic onver ted 1 00 ma r ine s h e l l a nd c ha r coa l s amp les t o b enzene f o r L S c oun t ing . T he b enz ene ( C 61 -6)

Rad iocarbon Da t ing b y L iqu id S c int i l lat ion Count ing o fB enzene T he r e h ave b een f ou r t e chn ique s b y w h ich t h e r a d ioac t ive d ecay o f ' 4C h a s b een m ea su red t o d e term ine t h e a ge o f a r chaeo log ica l a nd g eo log ica l s amp le s . T he f i r s t w a s t h e u se o f as c r een w a l led S o l id C a rbon C oun te r b y L ibby , Ar no ld a nd A nde r son a tt h e c l o se o ft h e 1 940 s ( Tay lo r 1 987 :76 , 8 2 ) . H e r e e l emen ta ry c a rbon w a s c oa ted o n to t h e i n s ide o f a m e ta l c on ta ine r a nd a G e ige r c oun te r p l aced i n s ide . T he G e ige r c oun te r m ea su red t h e n umbe r o f b e ta p ar t ic le s r a d ia t ing f r om t h es amp le o ve r ag i ven p e r iod o ft ime .

w a s p roduced t h rough a s e r ies o f c hem ica l r e a c t ion s i n v acuum s y s tems f o l low ing p rocedu re s a s s e t o u t b y H ogg ( 1982 ) a nd H ogg e ta l . ( 1987 ) . A n o u t l ine o ft h e p rocedu r e f o l low s . C a rbon d iox ide w a s f i r s t p roduced e i the r b y a c id h yd ro ly s i s o fc a rbona te s( u s ing d i lu te HC 1 )o rb y c ombu s t ion o fo rgan ic s amp le s :

D u r ing t h e e a r ly 1 950 s , t wo f u r the r t e chn ique s w e re d eve loped w h ich p rov ided i n c rea sed p r ec is ion i n ' 4C d ecay m ea su r emen t . G a s C oun t ing i n vo lved t h e c onve r s ion o ft h e

CaC O 3 > CO , HC I

1 0

CHAPTER 2

T he R ad ioca rbon Me thod

d i s se r ta t ion w e re c oun ted f o r 3 000 m inu te s t o a ch ieve a s t anda rd e r ro ro f ±4 0 y ea r s .

C+ 0 ,— > CO , h ea t D u r ing c ombu s t ion o f t h e o rgan ic s amp le s , t h e g a se s w e re p a s sed t h rough a p u r if ica t ion t r a in . T h i s i n c luded h ea ted c oppe ro x ide ( CuO ) t oa i d i nt h e o x ida t ion o f CO , NO , N ,O , NO , a nd t a r m a te r ia ls , s i lve r n i t ra te ( AgNO 3) ,t o p r ec ip i ta te a ny h a logen s , m e rcu r ic n i t ra te ( Hg (NO 3) , ) t o r emove h a logen s s t i l l p r e sen t , a nd p o ta s s ium i o d ide i ni o d ine ( K 1 / 1 2) a nd c h rom ic a c id ( K ,C r ,0 7)t or emove n i t rogen a nd s u lphu r c ompound s . Wa te r v apou r w a s r emoved b y s i l ica g e l a nd c oo led e t hano l t r aps ( 80 °C ) . C a rbon d i ox ide p roduced b y a c id h yd ro ly s i s o f c a rbona te w a s c l eaned o n ly b y t h e r emova lo fw a te rv apou r . T he Wa ika to l a bo ra to ry u t i l ise s 3 m 1 ( ca . 2 . 64g ) o fb enz ene f o r c oun t ing s t anda rd s amp le s . T h i s a moun t i sg ene ra ted b y a pp rox ima te ly 3 g rams o fc a rbona te , a nd 8t o 1 0 g ram s o f c ha r coa lo rw ood .

( when n o rma l ised t o

2 CO 3 +1 0L i — >L I ,C , +440 When r e ac t ion o ft he CO ,w i th t h e l i t h ium w a sc omp le te , t h e

" A . t h e u se o ft h e 5 568 y rh a lf l if e ( mean l i f e 8 033y ) ,

L i 2C2 + 2 H 20 — › C2H2 +2 L IOH

B . t h e a s sump t ion o f c on s tancy o f ' 4C a tmo sphe r ic l e ve l d u r ing t h e p a s t ,

T he a c e ty lene w a s p a s sed t h rough ap ho spho r ic a c id t r ap t o r emove a mmon ia c ompound s , a nd ac oo led e t hano l t r ap t o r emove w a te r v apou r . T he a ce ty lene w a s t h en t r ansf er r ed t o ac oo led v anad ium -ac t iva ted s i l ica -a lum ina c a ta ly s t c o lumn whe re i tw a st r ime r ised t ob enz ene :

C .t h e u se o fo xa l ic a c id ( d i r ec to ri n d i rec t )a s as t anda rd , D .

T he b enz ene w a s t hen c o l lec ted b y h ea t ing t h e c a ta ly s t i na n d own

t h e

b enzene

v apou r

p roduced u nde r a c t ive v acuum a t6 5 °C . U pon t h aw ing , t h e b enzene w a s t h en t r ansf er red i n to a t ef lon b acked s c rew c apped v i a l , a nd p laced i n af r eez e r f o r s t o rage . B enzene s amp le s a r e g ene ra l ly s t o red f o r o ne mon th t o a low t h e d ecay o fr a don ( 2 2 R n ) t o o ccu r i fi ts hou ld b e p re sen t ( t he h a lf l if e o f

2 22

Rn

i s o top ic

f r ac t iona t ion

n o rma l i sa t ion

o f

a l

s amp le

a c t iv i t ie s t ot h e b a se o f5 '3C = 2 5% 0 ( r e la t ive t ot h ec1 30 1 2 r a t io P DB ) [ PDB b e ing t h e P ee D ee B e lemn i te f r om t h e g eo log ica l f o rma t ion o f t h is n ame i n t h e U n i ted S t a te s ( H igham 1 993 :23) . R ecen t ly , t h e PDB n omenc la tu re h a s c hanged t o VPDB a s t h i s s t anda rd h a s b een a l te r ed s l igh t ly ( Long 1 995 : i i ) ] ,

3 C 2H2 — > C6H6

f r eez ing

C pD B =2 5% o ) e qua ls 0 .95 t i me s t h e

A l l c onven t iona l r ad ioca rbon a ge s ( o r CRA 9)u sed i nt h i s t h e s i s w e re c a lcu la ted a c co rd ing t o S t u ive r a nd P o lach ( 1977 :355 -363) a nd t h e ref o r e i n c lude t h e f o l low ing ( S tu ive r a nd P o lach 1 977 :356 ) :

l i t h ium c a rb ide w a s h ea ted a t8 00 °C f o r 3 0 m inu te s u nde r a c t ive v a cuum t o r emove u n r eac ted g a se s . T he L i ,C , w a s t h en l e f t t oc oo l t o r oom t empe ra tu r e . When c oo l , d i s t i l led w a te rw a sa dded t ot h eL i ,C ,t op roduce a ce ty lene ( C ,H 2) :

a nd

5 "

o l d o xa l ic a c id a c t iv i ty ( no rma l i sed t o 5 1 3 C pD B 19 % or ( S tu ive r 1 983 :794 ) . T he y ea r 1 9 50 i su sed a s 0y ea r s B P i n r a d ioca rbon d a t ing , a st h is y ea r w a s c l o se t ot h e p ub l ica t ion o f t h e f i r s t r ad ioca rbon d a te s b y Ar no ld a nd L ibby i n D ecembe ro f1 949 ( Tay lo r 1 987 :5 ) . L a te r , t h e y ea r 1 950 h ad a n a dd i t iona l u se a s i tw a s a f t e r t h is t ime t h a t many a t om ic t e s t s w e re u nder taken w h ich a f f ec ted t h e n a tu ra l ' 4C l e ve l i n t h ec a rbon e xchange r e se rvo i r .

T he CO , p roduced t h rough h yd ro ly s i s o r c ombu s t ion w a s t h en s l ow ly a dded i n to a v e s se l c on ta in ing 1 7g o f mo l ten l i t h ium ( L i ) ,p roduc ing l i t h ium c a rb ide ( L i ,C 2) :

1 00 °C o ven ,

I nd e r iv ing ar a d ioca rbon a ge f r om a n a r chaeo log ica l s amp le , w e m ea su re i t s c oun t r a te a nd c ompa re t h is t o modern s t anda rd a nd b ackg round c oun t r a tes . T he t wo i n te r na t iona l modern s t anda rd s u sed a r e HOx l ( Oxa l ic a c id I )a nd H0x 1 1 ( Oxa l ic a c id I ) ( Long 1 995 : i i i ) . A n i mpor tan t s e conda ry s t anda rd i s ANU ( Aus t ra l ian N a t iona l U n ive r s i ty ) s uc ro se ( s ee S t u ive r a nd P o lach 1 977 :355 ; G up ta a nd P o lach 1 985 :103 ) . A l l t h ree s t anda rd s a r e e mp loyed a tt h e Wa ika to l a bo ra to ry ( Hogg 1 982 :40 -43 ; G up ta a nd P o lach 1 984 :104 ) . B y i n te rna t iona l c onven t ion , t h e mode rn s t anda rd i st a ken a s 9 5% o ft h e n e t a c t iv i ty o ft h e O x I s t anda rd . T h is a c t iv i ty i s e qua l t ot h e c oun t r a te o f 1 890 w ood , c o r r ec ted f o r d ecay t o 1 950 ( Gup ta a nd P o lach 1 985 :103 ) . W i th t h e n ew o xa l ic a c id s t anda rd H0x 1 1 , " 0 .7459 t i me s t h e n ew o xa l ic a c id a c t iv i ty

E . t h e y ea r 1 950 i sa u toma t ica l ly t h e b a se y ea r , w i th a ge s g i ven i ny ea r s B P( i e ,p r e sen t i sAD 1 950 ) ." I s o top ic f r ac t iona t ion f o re a ch s amp le r a d ioca rbon d a ted w a s d e te rm ined b y aVG M ic roma s s 6 02C Ma s s S pec t rome te r a t t h e U n ive r s i ty o f Wa ika to .

i s o n ly 3 . 82 d ay s ) ( Gup ta a nd P o la ch

1 985 : 108 109 ) . T h is i si mpo r tan ta st h is i s o tope a l so e m i t s [ 3 p ar t ic le s o f s im i la r e ne rgy t o ' 4C b e ta e m i s s ion s , t h e ref o r e i n te rf e r ing w i th t h e i r m ea su r emen t a nd a l te r ing t h e a ppa r en t r ad ioca rbon a ge .

C onven t iona l r ad ioca rbon a ge s a r e c a lcu la ted u s ing t h e r ad ioca rbon d ecay e qua t ion : t=-8 033 I n (A s n / Ao n )

Af te r o ne mon th t h e b enz ene w a s t h awed a nd t h en t r ansf e r r ed i n to a s t anda rd Wa ika to S yn the t ic S i l ica 3 m 1 c oun t ing v i a l ( Hogg e ta l . 1 99 1 :123 ) . T he s c in t i l la to r b u ty l P BD ( C„H„N 20 ) ( s ee P o lach 1 992 :200 -20 1) , w a s t h en d i sso lved i nt h e s amp le b enzene a t ac oncen t ra t ion o f 1 5g / 1 . Af t e r d i s so lu t ion o ft h e s c in t i l la to r , t h e b enzene s amp le w a s p laced i n aWa l lac 1 220 Q uan tu lus s pec t rome te r ( s ee L owe a nd H ogg 1 992 ; H igham 1 993 ) . B enzene s amp le s f o r t h is

w he re 8033 i st h e m ean l i f e t ime o f ' 4C , As n t h e n e t s amp le c oun tr a te , a nd Am t h en e ta c t iv i ty o f0 . 95 H0x 1 .

Whe r e CRA i sf ound i nt e x to ri nt a b le s i nt h is s t udy i tr e f e r st ot h e C onven t iona l R ad ioca rbon A g e . 9

1

T he R ad ioca rbon Me thod

CHAPTER 2

i n to a ccoun t f o r e ach a ge , a long w i th t h e c oun t ing e r ro r ( E i ) ( s ee Wa rd a nd W i lson 1 978 :21-23 ) . T he ref o re , t h e v a r iab le

T he r e su l t ing c onven t iona l r a d ioca rbon a ge c a lcu la ted i s g i ven i ny ea r s B P a nd h a s a n a s soc ia ted l a s t anda rd e r ro r , f o r e xamp le 6 00 ± 4 0 y ea r s B P . A t t h e Wa ika to l a bo ra to ry , CRAs o fl e s s t h an 1 000 y ea r s a r e r ounded t ot h e n ea re s t 1 0 y ea r s , a nd t h e a s soc ia ted e r ro r t ot h e n ea re s t 5y ea r s u p f o r e r ro r s l e s s t h an 5 0 y ea r s ( s ee S t u ive r a nd P o lach 1 977 :362 ) . I ft h e r e se rvo i r c o r rec ted r a d ioca rbon a ge i sl e s s t h an 2 00 y ea r s B P ,t h en b yc onven t ion ,t h e a ge i st e rmed ' Moder n ' .

Es 2 .i nt h e f o rmu lae g i ven a bove f o rC a s e 1 ,i sr e p laced b y t h e v a r iab le S, w he r e S

( Wa rd a nd W i lson

A l l c onven t iona l r a d ioca rbon a ge s i nt h i s d i s ser ta t ion w e re c a l ib ra ted t oy ea r s AD a t l a u s ing t h e c a l ib ra t ion p rog ram CAL IB 3 . 0 .3 d eve loped b y S tu ive ra nd R e ime r ( 1993 ) . T h is p rog ram p r ov ides t wo i n ter na t iona l ly a c cep ted a tmo sphe r ic c a l ib ra t ion s c u rve s f o r t h e c a l ib ra t ion o f t e r re s t r ia l b a sed s amp les . F o r N ew Z ea land a r chaeo log ica l c ha r coa l s amp le s , t h e S tu ive r a nd B ecke r ( 1993 ) d e cada l a tmo sphe r ic c a l ib ra t ion c urve w a s u sed a s o ppo sed t ot h e b i decada l , a s t h i s c urve i sb a sed o n s amp les w i th s h o r t l i f e span s a nd l i t t le i n bu i l t a ge , w he rea s t h e b idecada l c u r ve i s a pp l icab le t o s amp les w i th l o nge r l i f e spans a nd u nknown i n bu i l t ar ( H igham 1 993 :25 ) . As ou thern h em i sphe r e o f f se t o f40 C y ea r s w a s a pp l ied t o c ha rcoa l CRA b ef o re c a l ib ra t ion , a s r e commended b y V oge le ta l . ( 1993 :74 ) . 1°

STAT IST ICAL ANALYS IS AND CAL IBRAT ION OF CONVENT IONAL RAD IOCARBON AGES ( CRA ) A l l s t a t is t ica l c a lcu la t ions i n t h is s t udy w e re u nde r taken u s ing t h e s t a t is t ica l t e chn ique s o f Wa rd a nd W i l son ( 1978 ) f o r t h e c ompa r i son a nd c omb in ing o fr a d ioca rbon a ge s . T h is m e thod w a s a l so u sed b y H igham ( 1993) f o r p oo l ing r a d ioca rbon a ge s f r om N ew Z ea land a r chaeo log ica l s i te s . H e re t h e s t a t i s t ica l r e la t ionsh ip b e tween a s e t o f d a te s i s f ound b y u nder tak ing aT te s t o n t h e p oo led d a te s . Wa rd a nd W i lson ( 1978 :20 ) e xp la in t h a t w hen p oo l ing r a d ioca rbon a ge s t h e r e a r e t wo C a se s f o r c ons ide ra t ion . I n C a se 1 ,t h e r a d ioca rbon a ge s c ome f r om t h e s ame o b jec t o rp a r t s o ft h e s ame o b jec t ; i nC a se 2t h e a ge s a r e n o t k nown o rc anno t b e p r e sumed t o b e f r om t h e s ame o b jec t . I n c omb in ing r ad ioca rbon a ge s f r om a s i ng le l a ye r i n a n a r chaeo log ica l s i te , w e u se t h e C a se 1c ons ide ra t ion . T o t e s t t h e h ypo the s is t h a tt h er a d ioca rbon a ge sa r e s im i la r , w e p oo l o u rs e to fd a te s b y u s ing t h e f o rmu la :

Ma r ine s he l l c onven t iona l r ad ioca rbon a ge s w e re c a l ib ra ted u s ing t wo d i f f e ren t t e chn iques t o a s ce r ta in w h ich m e thod i s mo re s u i tab le f o r c a l ib ra t ing N ew Z ea land m a r ine s he l l s amp les ( s ee C hap te r 5 ) . F i r s t ly , m a r ine s he l l CRAs w e re c a l ib ra ted b y s ub t rac t ing t h e c ur ren t N ew Z ea land R e se rvo i r C or rec t ion o f3 85 y ea r s ( McFadgen 1 9 78 :384 -390 ) , a nd t h en c a l ib ra t ing t h e r e su l t ing a ge o n ad ecada l a tmo sphe r ic c a l ib ra t ion c u rve ( i n t h is c a se u s ing t h e CAL IB 3 . 0 .3 S t u ive r a nd B ecke r ( 1 993) c u rve ) . T h is t e chn ique h a s b een u sed f o r m any y ea r s t o c a l ib ra te N ew Z ea land m a r ine s he l l CRAs . S econd ly , m a r ine s he l l c onven t iona l ' 4C a ge s w e re c a l ib ra ted u s ing t h e S t u ive r a nd B raz iuna s ( 1 993 ) mode l led m a r ine c urve ( a lso a va i lab le w i th t he CAL IB 3 . 0 .3 p rog ram ) , a nd a pp ly ing aA R c or rec t ion o f25 ± 1 5y ea r s a sr e commended b y H igham a nd H ogg ( 1995) ( s ee C hap te r 5 ) . T h is m a r ine c u rve b a se s i t s c a l ib ra t ions o n am od e l o f d i f f us ion a nd movemen t o f ' 4C t h rough t h e wo r ld 's o ceans . I th a s b een a r gued t h a t t h e mode l led ma r ine c u r ve p rov ide s a mo re r e a l is t ic m e thod o f c a l ib ra t ing m a r ine s h e l l c onven t iona l r a d ioca rbon d a te s i n to c a lenda r d a te s , a st h e c a l ib ra t ion s a r e b a sed o n t h e s amp le s ' o wn ' 4C r e se r vo i r p a rame te r s ( s ee S t u ive re ta l . 1 986 ; S t u ive ra nd B raz iuna s 1 993 ) .

A p = d A i / E fA iv E f ) w he re A p i s t h e p oo led m ean r ad ioca rbon a ge , A i t h e r a d ioca rbon a ge i ny ea r s B P , a nd E i i st h e s t anda rd d ev ia t ion a s soc ia ted w i th t h is a ge (Wa rd a nd W i l son 1 978 :19 ,21) . T o e va lua te w he the r t h e p oo led a ge s a r e s t a t is t ica l ly i n d is t ingu i shab le ,w e u se t h e T te s t : T= is ( A i — Ap )2/Ef w he re T h a s ac h i squa re d i s t r ibu t ion o fn 1 . T he T te s t m ay b e u nde r taken a tt h e 1o r 2s i gma p robab i l i ty c onf idence l e ve l . I n t h is s t udy , a l s t a t is t ica l c ompa r isons a r e a tt h e 2 s i gma l e ve l ( 9 5% ) ( P =0 . 05 ) . I ft h e a ge s a r e n o t s t a t is t ica l ly d i f f e ren t t h en t h ey m ay b e c omb ined a nd t h e v a r iance c a lcu la ted u s ing t h ef o rmu la :

V (Ap) = (

= E, 2+ F ;

1 978 :23)

l IE , 2) 1

w he re V (Ap ) " i s t h e v a r iance o ft h e m ean o ft h e g roup o fn o b se rva t ion s a nd n o t t h e v a r iance o f t h e d e term ina t ions ." ( Wa rd a nd W i lson 1 978 :23 ) .

g roup

o f

When e s tab l i sh ing w he the r mu l t ip le l a ye r s i n a n a r chaeo log ica l s i te w e re d epo s i ted a tt h e s ame t ime , aC a se 2 c ons ide ra t ion i s u sed . T h i s i s b ecause e ach d a ted l a ye r r e p re sen t s as i ng le e ven t ( o ro b jec t ) , a nd s o a l l a ye r s c anno t b e p r esumed t o b e c on tempo ra ry . C a lcu la t ing A p , T , a nd V( Ap ) i nt h eC a se 2c ons ide ra t ion u ses t h e s ame f o rmu lae a s f o r C a se 1 , b u t a s e ach l a ye r r ep re sen t s a n e ven t a t a p a r t icu la rp o in t i nt ime e xp re s sed b y i t sr a d ioca rbon d a te , t h e e r ro ra s soc ia ted w i th t h e c a l ib r a t ion c u rve ( F l )m us tb et a ken

s i nce c omp le t ion o ft h i s r e sea r ch , CAL IB 4 . 0( s ee S t u ive ra nd R e im e r 1 993 ) h a sb een r e lea sed w h ich i n co rpo ra te s t h en ew S t u ive re ta l . 1 998a a nd S t u ive re ta l . 1 998b c a l ib ra t ion d a ta se t s . I na dd i t ion , p r e l im ina ry r e su l t so n c u r r en tr e sea r ch r e ga rd ing t h e s ou thern h em isphe r ec o r r ec t ion s ugge s t st h is c o r r ec t ion m ay n ow b e 2 7 " C y ea r s( McCo rma ce ta l . 1 998 ) . T he r e v i s ed CAL IB 4 . 0p rog ramme a nd t h e p ropo sed n ew s o u the r n h em i sphe re c o r rec t ion d o n o ta f ec tt h e r e su l t so ft h is r e sea r ch . 1 0

1 2

CHAPTER 3

THE SA MPLE TYPE D ILE M MA I N RAD IOCARBON DAT ING NE W ZEALAND ARCHAEOLOGY " I tm u s tb ea ppa ren tf rom t h e se v a r iou sa rgumen t st ha tt h ere i sn os y s tema t ic m a rg in o fe r ro rb e tween r ad ioca rbon d a te so n s amp l e so fd if f e ren tt y pe ." A nd e r son ( 1991 :781 )

H oweve r , i n 1 965 , L ocke rb ie r e ce ived a mendmen t s t o h i s e a r l ie r 1 957 m a r ine s h e l l a ge s f r om t h e U ppe r a nd I n te rmed ia te l a ye r s a t P ounawea ( Locke rb ie 1 980 ) . T he m a r ine s he l l CRAs h ad b een " co r rec ted " b y t h e I GNS r a d ioca rbon l a bo ra to ry a c co rd ing t o n ew r a d ioca rbon c a lcu la t ion m e thod s . T he r e ca lcu la ted m a r ine s he l l a ge i nt h e I n te rmed ia te l a ye r w a s n ow o l de r t h an i t s p a i red c ha rcoa l a nd s e a l d a te s , w i th t h e n ew r e ser vo i rc o r rec ted a ge o f6 60 ± 6 0 y ea r s B P . L ocke rb ie ( 1 980 ) c ou ld n o t e xp la in w hy t h e m a r ine s he l l a ge w ou ld b e o l de r t h an t h e o t he r s amp le t y pe s d a ted . T h i s i n i t ia l o bserva t ion o n d i f f e r ence sb e tween s amp le t y pe s b y L ocke rb ie w a s n eve r r e so lved , a nd t h e c on t rove r sy o ft h e c h rono logy o fP ounawea c on t inued f o r2 3 y ea r s .

I NTRODUCT ION P o s s ib ly t h e m o s t c ommon m e thod u s ed b y a r chaeo log i s t s t o day f o r p l ac ing a n a r chaeo log ica l e ven t i ni t s p reh i s to r ic t i me f r ame i s r ad ioca rbon d a t ing . I n c oun t r ies w he re p r eh i s to ry e x tend s b ack o ve r t hou sand s o fy ea r s , t h e u se o f d i f f e r ing s amp le t ype s f o r r a d ioca rbon d a t ing a n a r chaeo log ica l s i te c an a f f ec tt h e c h rono log ica l o u tcome , b u t n o t t ot h e s c a le a tw h ich i tc ou ld h e re i nN ew Z ea land . W i th h uman o ccupa t ion c omp r is ing a bou t 9 00 y ea r s , p rob lems e ncoun te r ed i nu s ing v a r ious m a te r ia ls f o rd a t ing p r eh is to r ic e ven t s w i th in t h is p e r iod may b e f a r m o r e s i gn if ican t . I ti s t h e ref o r e v i ta l f o r N ew Z ea land p r eh i s to ry t h a t v a r ia t ion s i n r a d ioca rbon a ge b e tween d i f f e r ing s amp le t y pe s f r om t h e s ame s t ra t ig raph ic c on tex tb e i n ve s t iga ted .

T ro t ter ( 1967 , 1 968 )

T h i s c hap te rp r e sen t s ah i s to r ic r e v iew o fp a s t i n ve s t iga t ions a nd o p in ion s o n d i f f e rences b e tween r a d ioca rbon d a te s f r om v a r ious m a te r ia l s , a nd t h e r e l iab i l i ty o f p a r t icu la r s amp le t y pe s , f o rd a t ing i nN ew Z ea land a r chaeo logy . I tw i l l b e s e en t h a t i n ve s t iga t ions o fs amp le t y pe h ave b een f ew i nn umbe r , e ven t hough o p in ions o n t h e r e l iab i l i ty o fv a r iou s m a te r ia ls h ave b een p r o l if ic .

I t w a s n o t u n t i l t wo y ea r s a f te r L ocke rb ie 's 1 965 o b serva t ion s , t h a t o the r a r chaeo log i s t s b egan t o i n ve s t iga te t h e s amp le t ype p rob lem . I n 1 967 , T ro t te r e xp r e s sed h i s c once rn i n a m emo t o D uf f ( a t t h e t ime b o th w e r e a r chaeo log i s t s a t t h e C an te rbu ry Museum ) o ve r a ge v a r ia t ions b e tween c ha r coa l , b one c o l lagen , a nd r e servo i r c o r rec ted m a r ine s he l l s amp le s f r om a r chaeo log ica l s i t e s i n t h e S ou th I s land ( Leach 1 9 67 ) ( Tab le 3 . 1) . H e n o ted , " . . the a ge o fc ha rcoa l s amp le s i sa lmo s t c on s i s ten t ly 3 00 -400 y ea r s e a r l ie r t h an c o l lagen o rs h e l l f r om t h e s ame l e ve l" , b e l iev ing t h a t , " I n s ome c a se s t h i s i sd ue t o t h e u se o f o l d o r r e l ic t i mbe r , b u t t h i s c anno t a pp ly w he re t w ig s a r e s e lec ted ." ( T ro t te r 1 967c ) .

I NVEST IGAT IONS AND OP IN IONS ON SA MPLE CHO ICE AND REL IAB IL ITY I N RAD IOCARBON DAT ING NE W ZEALAND ARCHAEOLOGY : A H ISTOR ICAL REV IE W L ocke rb ie ( 1957 )

I n 1 968 , T ro t te r f u r the r i n ve s t iga ted i regu la r i t ie s b e tween r a d ioca rbon a ge s o n v a r iou s m a te r ia ls f r om e xcava ted a r chaeo log ica l c on tex t s . H ec on s ide red a ga in t h er a d ioca rbon c h rono log ie s o f t h e moa -hun t ing s i te s T a i R ua , Woo lshed F l a t , a nd R edc l if f s , a nd t h e p a a t K a t ik i P o in t , a nd a dd i t iona l ly t h e r ad ioca rbon d a te s f r om Moa -bone P o in t C ave ( Tab le 3 . 2 ) . T ro t te r ( 1 968 ) b e l ieved t h a t t w ig s a nd s ma l l d i ame te r p i ece s o f c ha rcoa l s hou ld y i e ld a c cu ra te r a d ioca rbon d a te s , b u t f o und t h a t t h e c ha r coa l CRA s f r om t h e se s i te s w e re c ons i s ten t ly s eve ra l c en tu r ie s o l de r t h an r e se rvo i r c o r r ec ted r a d ioca rbon d a te s o n o t he r m a te r ia ls . T ro t te r ( 1968 ) p ropo sed t h a t t h e c ha r coa l d a ted f r om T a i R ua , Woo lshed F l a t , R edc l if f s , Moa -bone P o in t C ave a nd K a t ik i P o in tc ame f r om r e l ic t i mbe r , p robab ly d r if twood , a nd t h i s w a s t h e r e a son f o r t h e v a s t a ge d i f f e r ence s b e tween t h e m a r ine s he l l a nd moa b one c o l lagen r a d ioca rbon d a te s , a nd c ha r coa l a ge s . H e s ugge s ted t h a t o n ly t h e m a r ine s he l l a nd c o l lagen d a te s s hou ld b e a ccep ted a s r e l iab le ( T ro t te r 1 968 :86 ) .

O b serva t ion s t h a t d i f f e ren t s amp le t y pe s f r om t h e s ame a r chaeo log ica l c on tex t e xh ib i ted v a r ied r a d ioca rbon a ge s e x tend b a ck t o t h e 1 950 s . L ocke rb ie ( 1 980 ) b egan e xpe r imen t ing i n 1 957 w i th t h e s u i tab i l i ty o f c ha r coa l , m a r ine s h e l l , a nd s ea l b one f o r d a t ing t h e P ounawea a r chaeo log ica l s i te i nt h e S ou th I s land ( F igu r e 3 . 1) . T he s i te c on ta ined t h r ee c u l tu ra l l a ye r s : a n U ppe r l a ye r h av ing a r e servo i r c o r rec ted ma r ine s he l l a ge o f2 90 6 0 y ea r s B P ( NZ -54 ) ; a n I n te rmed ia te l a ye r w i th a r e se rvo i r c o r r ec ted m a r ine s h e l l a ge o f5 00 ± 6 0 y ea r s B P ( NZ -57 ) , ac ha rcoa l a ge o f 5 20 ± 5 5 y ea r s B P ( NZ -55 ) , a nd as e a l b one a ge o f 50 ± 5 y ea r s BP ( NZ -56 ) ; a nd a L owe r l a ye r w i th a c ha rcoa l d a te o f8 10 ± 6 0 y ea r s B P ( NZ -58 ) . At r ee g row ing o n t op o ft h e s i te w a s d end roch rono log ica l ly d a ted t o 2 24 y ea r s a go . L ocke rb ie ( 1980 ) n o ted t h a t t h e se r ad ioca rbon d a tes s uppo r ted t h e c u l tu ra l s equence o f t h e s i te , a nd t h e d i f f e ren ts amp le t ype sw e re a l l i nc h rono log ica l a g reemen t .

1 3

T he S amp le T ype D i lemma

C II APTER 3

K ey •

A rchaeo log ica l s i te o rs i tes

Ce l

L .T aupo

F ox ton Awa ro

0

Wa i rau B a r

A voca P o in t o rF yf f e s O ld P i e rP o in t

Weka P a s so r P en t land D own s•

Moa -bone P o in tC ave ç jR edc l if f s

R aka ia Wakanu i

B o l ton 'se G u l ly

4 1 ) •

T a i R ua Awamoa O tu rehua • O to ta ra f lW a ima ta i ta i

T akahe V a l ley

H awk sbu rn R ock f a l l C reek I t a l ian C reek

Wakapa tu R iver ton

T iwa i P o in t

P u rakanu i

Woo lshed F l a t J unc t ion P o in t A hu r i r i G oo seneck B end K a t ik i P o in t H ampden

S hag Mou th P l ea san tR ive r

P ounawea C ann iba l B ay

0

a pa towa i

1 00 k i l omet r es

S tewar tI s land

F igu re 3 . 1 . L oca t ions o fa r chaeo log ica l s i t e sd i scu s sed i nC hap te r3 .

1 4

2 00

CHAPTER 3

T he S amp le T yp eD i lemma

S i te N ame

Charcoa l ( BP )

Mar ine s he l l ( BP )

Moa b one c o l lagen ( BP )

T a i Rua ( S 136 / 1)

8 31 ±3 ( NZ -594 )

4 85 ± 3 7( NZ -749 )

5 03 + 3 2 ( NZ -578 )

Woo lshed F la t ( S 117 /3 )

8 60 ± 5 0( NZ -798 )

-

4 93 ± 7 0 ( NZ -760 )

R edc l if f s ( S84 /76 )

170 ±6 0 ( NZ -438 )

6 17 ± 3 4 ( NZ 1111)

NZ 1113) 7 35 ± 5 6(

K a t ik i P o in t ( S 146 /4 )

8 80 ± 3 9( NZ -696 )

6( 2 11 ± 5 NZ -697 )

-

T ab le 3 . 1 . V a r ia t ions i n r ad ioca rbon a ge o n d i f f e ren t s amp le t ypes f r om N ew Z ea land a r chaeo log ica l s i tes o bse rved b y T ro t te r( 1967c )( ma r ine s he l l r ad ioca rbon d a tes a r er e servo i rc or rec ted ) .

S i te N ame

C harcoa l

Mar ine s he l l

Moa b one c o l lagen

T a i R ua ( S 136 / 1)

119 ± 3 3 AD ( NZ -594 )

1 465 ± 3 2 AD ( NZ -749 ) ( Ha l io t i s i r i s )

1 447 ± 3 2 AD ( NZ -578 ) 1 447 ± 3 2 AD ( NZ -578 ) 1 407 ± 3 2 AD ( NZ -752 )

-

1 457 ± 7 0 AD ( NZ -760 )

7 80 ± 6 5 AD ( NZ -438 )

1 333 ± 3 4 AD ( NZ 1111) ( Aus trovenu ss t u tchbu ty i )

1 215 ± 5 6 AD (NZ 1113)

Moa -bone P o in tC ave ( S84 /77 )

163 ± 8 2 AD ( NZ -459 )

-

1 460 ± 9 0 AD ( NZ -460 ) ( Ca rbona te )

K a t ik i P o int ( S 146 /4 )

1 070 ± 3 9 AD ( NZ -696 )

1 739 ± 5 6 AD ( NZ -697 ) ( s p .? )

-

Woo l shed F la t ( S 117 /3 )

1 090 ± 3 2 AD ( NZ -798 )

R edc l if f s ( S84 /76 )

140 ± 5 0 AD ( NZ -783)

T ab le 3 . 2 . T ro t te r 's ( 1968 ) c ompa r ison o f c ha rcoa l , ma r ine s he l l a nd moa b one r ad ioca rbon d a tes f r om N ew Z ea land a r chaeo log ica l s i tes . ( T ro t te r s ub t rac ted e ach r e se rvo i r c or rec ted CRA f r om 1 950 AD t od e r ive y ea r s AD ) .

ma te r ia ls w e re i mmune t o s o la r e f f ec t s , b u t f r eshwa te r s he l l a nd moa c rop ma te r ia l wou ld b e a f f ec ted .

I nc onc lus ion T ro t te r( 1968 :86 -87 ) s t a ted : " .on t h i s b a s i s Ia m s u sp i c iou s o ft h e a c cu racy o fa ny c ha r coa l d a t e n o t s uppo r t ed b y d a t e s o b ta ined f r om o t her m a t e r ia l s o r m e thod s . . .I nv i ew o ft h e u nc er ta in t i e s i n vo l v ed t h er e w ou ld a pp ea r t o b e l i t t l e p o in t i n s ubm i t t ing a r cha eo log i ca l c ha r coa l f o r r ad iocarbon d a t ing e x cep ta s al a s tr e so r t w hen n o o t her m a t e r ia l s -s uch a ss h e l lo rb one c o l lag en -a r ea va i lab l e ."

C ou t t s ( 1972 ) C ou t t s ( 1972 :516 -531) d i scus sed p rob lems a s soc ia ted w i th d a t ing v a r ious s amp le t ypes b y l o ok ing a t 2 7 r ad ioca rbon d a tes f r om 1 5 s i tes . H e n o ted t h a t c ha rcoa l w a s n o t a lways e xc lu s ive ly o lde r t han o t he r c on tempo rary ma te r ia ls a s T ro t te r ( 1968 ) h ad o bserved ( Cou t t s 1 972 :524 ) . C ou t ts o b se rved t h a t o ne t h ird o f h i s a r chaeo log ica l s i tes w i th c ha rcoa l /ma r ine s he l l p a ir s h ad ar e se rvo i r c or rec ted ma r ine s he l l r a d ioca rbon a ge t ha t w a s o l de r t h an t h e c on tempo rary c ha rcoa l r ad ioca rbon a ge ( Cou t t s 1 972 : 5 27 ) . T he r ema in ing c ha rcoa l r a d ioca rbon d a tes f r om o t he r s i tes s howed g rea t v a r iab i l i ty w hen mu l t ip le c ha rcoa l a ge s f r om t h e s ame l a ye r w e re c ompa red . C ou t t s s ugges ted t h a t c hrono log ica l p rob lems a s soc ia ted w i th r ad ioca rbon d a t ing a r chaeo log ica l s i te s may b e a l lev ia ted b y mu l t ip le d a t ing a nd mo re r e sea rch o n t h e r e l iab i l i ty o f c er ta in ma te r ia ls ( Cou t t s 1 972 :524 ) .

L aw ( 197 1 ) L aw ( 197 1) c ons idered t h e e f f ec t o fs o la r c yc les a nd n uc lea r t e s ts o n r a d ioca rbon d a te s . H e s ugge s ted t h a t t w ig s , l e ave s a nd s eed s s hou ld n o t n ece s sa r i ly b e r e ga rded a s r e l iab le f o r d a t ing b ecause ' 4C f l uc tua t ions i n t h e b i o sphe re e ve ry 1 y ea r s ( due t os o la r c yc le s ) may a f f ec t t h e s hor t t ime s pan o f g row th . B a sed o n t h is , h e b e l ieved t h a t s ap l ing s i zed t w ig s wh ich s how a g ood n umbe r o fy ea r s o fg row th ( i e . s l owe r g row ing ) , a nd b one c o l lagen f r om l a rge f a una a r e t h e mos t r e l iab le f o r d a t ing ( Law 1 97 1 :65 ) . L aw n o ted t h a t ma r ine

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R af te r e t a l . ( 1972 ) t h en i n ve s t iga ted d i f f e rence s i n r a d ioca rbon a ge b e tween s amp le t y pes f r om N ew Z ea land a r chaeo log ica l s i te s ( F igu re 3 . 2 ) . F or ty f o u r r a d ioca rbon d a tes f r om 1 a r chaeo log ica l s i t e s a nd n a t u ra l s wamp d epo s i t s o f moa b one w e re c ompa red , t h e p l an t m a te r ia l b e ing c on tempo ra ry w i th t h e b one c o l lagen a nd s h e l l ( Raf t e r e ta l . 1 972 :631) . F rom t h e a na ly s i s , r ad ioca rbon d a te s f r om b one c a rbona te w e re f ound ( a s e xpec ted ) t o b e u n re l iab le . P l an t r ema ins w e r e c ons is ten t ly o l de r t han t h a t o f s he l l o r b one c o l lagen , b u t t h e s he l l a nd b one c o l lagen r a d ioca rbon a ge s w e re i nc l o se a g r eemen t . E xp lana t ions s ugge s ted f o rt h e a ge d i f f e r ence s b e tween t h e p l an t r ema ins a nd a s soc ia ted s he l l a nd b one , w e re t h e u se o f r e l ic l o g s b y t h e s i te s ' i n hab i tan t s ( s uch a s a t K a t ik i P o in t ( t o ta ra ) ) , o r t h a t t h e c ha rcoa l u s ed f o r d a t ing p oss ib ly c ame f r om t h e o u te r a nd i n ne rr i ng so fa nc ien tt r ee s ( a s p ropo sed f o rt h e R edc l if f s a nd Moa -bone P o in tC ave d a tes ) .

C ou t t sa l so s ugge s ted t h a t i n ve s t iga t ions o fa l terna t ive d a t ing m e thod s a pp rop r ia te t o a r chaeo logy m ay b e u sef u l ( Cou t t s 1 972 :524 ) . R af ter ,J an sen , L ocke rb ie a nd T ro t te r( 1972 ) R af te r , J an sen , L ocke rb ie , a nd T ro t te r ( 1972 ) c ons ide r ed d i ve r se o p in ions a nd o b se rva t ions r e ga rd ing t h e r e l iab i l i ty o f v a r ious s amp le t ypes f o r d a t ing . F o r m a r ine s he l l , R af t e r e t a l . ( 1972 ) n o ted t h a t T ay lo r a nd B e rge r ( 1967 ) s t re s sed t h e n ece s s i ty o f s t udy ing t h e m a r ine e nv i ronmen t f r om w h ich m a r ine s he l ls u sed f o r d a t ing a r chaeo log ica l c on tex t s w e r e d e r ived , a nd Mangerud ( 1972 )h ad e mpha s ised t ha ts he l l s a r e r e l iab le i f s amp le s w e re s e lec ted c a ref u l ly . T hey a l so o b served t h a t V a la s t ro a nd D av is 's ( 1970 ) c ompa r ison o f 1 2 p a i r s o f c ha rcoa l a nd r e se rvo i r c o r r ec ted s he l l a ges f r om a r chaeo log ica l s i te s i n T exa s , s howed t h a t s he l l w a s o l de r t h an c ha r coa l b y 1 . 36 s i gma f o r a l l p a i r s e xcep t t wo , b u t t h a t H ayne s e ta l . ( 197 1) r epo r ted l i t t le d i f f e rence b e tween t wo r e se rvo i r c o r rec ted s he l l a nd c ha rcoa l a ges f r om h i s s t udy ( Raf t e re ta l . 1 972 :627 -633 )

R af t e r e t a l . ( 1972 ) c onc luded f r om t h e i r c ompa r ison o f s amp le t y pe s , t h a t p l an t r ema ins u sua l ly g i ve r a d ioca rbon d a te s s eve ra l h und r ed y ea r s o lde r t h an r e se rvo i r c o r rec ted s he l l o rb one c o l lagen d a te s . T hey b e l ieved t h a t m a r ine s he l l a nd b one c o l lagen w e re mo r e r e l iab le f o r d a t ing N ew Z ea land a r chaeo log ica l s i tes ( Raf t e re ta l . 1 972 :644 ) .

R af t e re ta l . ( 1972 )t h en a s se s sed t h e s u i tab i l i ty o f moa b one f o rr a d ioca rbon d a t ing . T hey c ompa red c a rbon i s o tope r a t io s a nd d a te s o f moa b one c a rbona te f r om f ou r a r chaeo log ica l s i te s , w i th ac on tempo ra ry b one s t anda rd . R af te re ta l . ( 1972 ) f o und t h a t i s o top ic f r ac t iona t ion i n b one c a rbona te c ou ld i n t roduce s i gn if ican t r a d ioca rbon d a t ing e r ro r s f o r a r chaeo log ica l s amp le s , a nd t h a t b one c a rbona te r ad ioca rbon a ge s f r om s ome o f t h e a r chaeo log ica l s amp le s d a ted w e re a f f ec ted b y i n co rpo ra t ion o f b omb c a rbon . T hey c onc luded f r om t h e i rs t udy t h a t moa b one c a rbona te w a s n o t r e l iab le f o r d a t ing , b u tt h a t moa b one c o l lagen c ou ld b e , a s i lu s t ra ted b y c l o se a g reemen t b e tween moa b one c o l lagen d a te s a nd r e se rvo i r c o r rec ted s he l l a ge s f r om c on tempo ra ry a r chaeo log ica ld epo s i t s( Raf te re ta l . 1 972 :638 ) .

McCu l loch ( 1973 ) I n 1 973 , McCu l loch ( 1973 :130 131) p ropo sed ap r o toco l f o r o b ta in ing r e l iab le s amp le s f o r r a d ioca rbon d a t ing . O f t h e f ou rp o in t s i nh e rp ro toco l , t h e t wo mo s t i mpo r tan t w e re t h a t t h e ma te r ia l t o b e d a ted mus t b e a ccu ra te ly i d en t if ied , a nd t h a t t h e t i me o fd ea th o ft h e ma te r ia l b e c on tempo ra ry w i th t ime o fu se a tt h e s i te . S he i lus t ra ted t h e se t wo p o in t s u s ing t wo r ad ioca rbon d a te s f r om t h e Weka P a s s s i t e i n N o r th C an te rbu ry ; o ne f r om m a r ine s he l l ( Amph id e sma a u s t ra l i s ) o f 9 10 ± 1 32 y ea r s B P ( NZ 1534 ) , a nd t h e o t he r f r om c ha rcoa l ( Podoca rpu s t o ta ra -ha l l i i )o f 1 3 15 + 8 0 y ea r s B P ( NZ 1535 ) . McCu l loch ( 1973 :131132 ) e xp la ined t h a t b ecause c ha r coa l d a te s w e re u sua l ly s e vera l h und r ed y ea r s o l de r t h an m a r ine s he l l , a nd i ft h is w a s a l lowed f o r i nt h is i n s tance , t h en t h e c ha r coa l a ge w a s i na g r eemen t w i th t h e s he l l a ge . McCu l loch s ugge s ted t h a t w hen l o ok ing f o r e a r ly s i tes , " Ia m c onv inced t h a t t h e b es t a nd mo s t a u then t ic d a te s i n t h is d i r ec t ion a r e t o b e g o t f r om s ma l l i s o la ted s i tes s how ing o n ly o ne p e r iod o f o ccupa t ion - p e rhap s o ne i s o la ted v i s i t -r a the rt h an f r om t h e l a rge a nd o bv iou s ly w e l l e s tab l ished s i t es , e ven a t t h e i r l owe s t l e ve l s ." ( McCu l loch 1 973 : 1 3 1) .

R af te r e ta l . ( 1972 ) c ons ide red av a r ie ty o fo p in ions o n t h e r e l iab i l i ty o f b one f o r r a d ioca rbon d a t ing . F o r e xamp le , T ame r s a nd P ea r son ( 1965 ) o b se rved d a te s o n b one c a rbona te w e re u n re l iab le d ue t oc on tam ina t ion , b u t H ayne s ( 1 968 ) a nd H ayne s a nd L ong ( 1969 ) s t a ted t h a t t h e b one a pa t i te CO 2 d a t ing m e thod g ave mo re a ccura te r e su l t s t h an a ny o t he r b one f r ac t ion . I n d a t ing t h e c o l lagen f r ac t ion o f b one , R af t e r e t a l . ( 1972 :640 -643 ) n o ted S e l ls ted t e t a l . ( 1 966 ) w ho b e l ieved b one c o l lagen p rov ided r e l iab le r a d ioca rbon d a te s ( wh ich s hou ld b e mo re a ccu ra te t h an w ood ) ; H ayne s ( 1967 ) w ho b e l ieved o n ly c o l lagen w a s r e l iab le f o r d a t ing ; a nd f i na l ly B a rke r e t a l . ( 1971) w ho r e po r ted c l o se a g reemen t b e tween c ha r coa l a nd c o l lagen d a te s w hen a l t h e h um ic a c id s w e re e x t rac ted . R af t e r e ta l . ( 1 972 :64 1-642 ) a l so f ound , h oweve r , t h a t m any s t ud ie s c ou ld n o td ec ide o n t h e r e l iab i l i ty o fb one a ta l l , f o r e xamp le B a rke r ( 1967 ) w ho c ou ld m ake n o f i rm d ec is ion o n t h e s u i tab i l i ty o f b one f o r d a t ing ; G eyh a nd G uh l ich 's ( 1970 ) r e sea rch w h ich i n d ica ted t h a t b o th c o l lagen a nd a pa t i te s hou ld b e d a ted a nd c ompa red f o r amo re r e l iab le r e su l t , b u t t h e se d a te s s hou ld n o t b e c omp le te ly t r us ted ; a nd P o lach ( 1 97 1) w ho d a ted s i x b one s amp les f r om o ne a r chaeo log ica l s i t e t o i n ve s t iga te t h e r e l iab i l i ty o f d a t ing b one c a rbona te , a pa t i te , a nd r e s idua lo rgan ic c a rbon , a nd f ound n o a g reemen t b e tween d a te so nt h e se f r ac t ion s ( Raf t e re ta l . 1 972 : 6 42 ) .

G ran t -T ay lor ( 19 7 4 ) G ran t -Tay lo r ( 1974 ) p r e sen ted i n f o rma t ion r e ga rd ing t h e r e por t ing a nd c o l lec t ion o f s amp le s f o r r a d ioca rbon d a t ing . H e w a rned a r chaeo log is t s a ga ins t c o l lec t ing c ha r coa l f o r d a t ing b ecause o f i n bu i l t a ge , a s i lu s t ra ted b y R af t e r e ta l . ( 1972 ) . G ran t -Tay lo r ( 1974 : 1 59 ) b e l ieved t h a t t h e b e s t m a te r ia l f o r d a t ing w a s s ho r t l ived m a te r ia ls , s uch a s s h e l l , b one o r f l ax c o rdage , w h ich w a s d i rec t ly i n vo lved w i th t h e p r eh is to r ic e ven t b e ing d a ted . H e a l so n o ted t h a t i fd a t ing c ha rcoa l o r w ood , o n ly t w ig s s hou ld b e u sed , a nd w hen u s ing s h e l l , t h a t a r agon i te s hou ld b e t e s ted f o r r e crys ta l l i sa t ion b y XRD .

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L Il owe r l e ve l . m l . m idd le l e ve l . t . l .t op l e ve l . F igu r e3 . 2 . C ompa r ison o fr a d ioca rbon a ge s o n d i f f e ren t s amp le t ype s f r om N ew Z ea land a r chaeo log ica l s i t e s b y R af t e re ta l . ( 1972 ) . m ay o ccu r ; 4 )f i sh b one m ay b e u s ed , e s pec ia l ly v er teb rae , i f t h ey c an b e i d en t if ied a nd a ged ; 5 )m oa b one w a s g ood f o r d a t ing , a nd m ay d i rec t ly d a te moa -hun t ing ; 6 ) i d en t if ied s ma l l b i rd b one c an b e u sed , b u t l a nd a nd s e ab i rd s s hou ld b e k ep t s epa ra te ; a nd 7 ) as amp le s hou ld b e c a ref u l ly a s soc ia ted w i th t h e e ven t t o b e d a ted , a nd a s t ra t ig raph ic c o lumn p rov ided s ot h a tt h ep o s i t ion o fe ach s amp le m ay b em a rked .

G ran t -Tay lo r ( 1 974 : 1 59 ) e xp la ined t h a t s he l lf i sh s u ch a s p ec tens , m u s se l s , a nd o y s te r s s hou ld n o t b e u sed f o r d a t ing a s r e c rys ta l l i sa t ion c anno t b e d e tec ted , a nd Amph ibo la s hou ld b e a vo ided a s i t i n ge s t s o l d c a rbon f r om t h e e nv i ronmen t .H ea l so s ugge s ted t h a t : •

w hen d a t ing h uman a nd moa b one , c a rbona te s hou ld n o t b ed a ted ,a nd t h a tc o l lagen w a sp r ef e r r ed ;

•

t h a t s o i l sw e re n o to r ious f o rd a t ing ;

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f i sh c ou ld b e al i ke ly s ou r ce f o r d a t ing a r chaeo log ica l s i tes t h a t h ad g ood s t ra t ig raphy o r d i s t ingu i shab le a r tef a c t s ,t h ough s pec ie s i d en t if ica t ion w a s i mpo r tan t ;

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a nd f i na l ly t h a t w ha le b one w a s n o t au sef u l c on s t i tuen t f o r a r cha eo log ica l d a t ing , b u t s e a l b one h ad b een n o ted a s p roduc ing d a te s w h ich a g reed c l o se ly w i th o t he r m a te r ia l s b e l ieved t o b e r e l iab le ( G ran t -Tay lo r 1 974 : 1 59 160 ) .

McCu l loch a nd T ro t te r( 1975 ) McCu l loch a nd T ro t te r 's ( 1975 ) s t udy o n t h e c h rono log ica l d i s t r ibu t ion o f moa -hun t ing s i te s i n t h e S ou th I s land h i gh l igh ted t h e s amp le t y pe p rob lem . O ft h e 1 80 r a d ioca rbon d a tes a va i lab le f r om S ou th I s land a r chaeo log ica l s i te s , 8 8 w e re u sed i n t h e i r a na ly s is . D a te s a nd s i t e s c ons ide red d ub ious b y t h e a u tho r s w e re w i thd rawn b a sed o n ap ro toco l w h ich c on s ide red t h e u n re l iab i l i ty o f b one c a rbona te , u n re l iab le p rovenance o fs amp le s t om oa -hun t ing s i te s , d a te s f r om r e l ic t imbe r , a nd l a ck o ff i rm e v idence f o r moa -hun t ing a s soc ia ted w i th t h e d a te . T he r a d ioca rbon d a te s w e r e t h en a na ly sed b y s amp le t ype , p rov id ing 2 0 moa b one c o l lagen , 1 8 m a r ine s he l l , a nd 4 4 c ha rcoa l r a d ioca rbon d a te s , w i th 6 r a d ioca rbon a ges c om ing f r om o t he r m a te r ia ls . T h i s a na ly s i s p roduced p e rhap s o ne o ft h e mo s t w e l l k nown i l us t ra t ion s o n s amp le t ype d i f f e r ence s i n N ew Z ea land a r chaeo logy ( F igu re 3 . 3 ) .

A g u ide l ine p r esen ted b y G ran t -Tay lo r ( 1974 : 16 1162 ) c on ta ined 1 3 s t eps f o r e f f ec t ive d a t ing o f a r chaeo log ica l s i t e s . I n s umma ry , h e b e l ieved t h a t : 1 )s amp le s s hou ld n o t c ome f r om i s o la ted s i ng le d epo s i t s , b u t f r om m u l t i laye red s i t e s w he r e s amp les c an b e c o l lec ted f r om a l l l a ye r s ( c f . M cCu l loch 1 973 :131) ; 2 ) c ha rcoa l c o l lec t ions s hou ld b e f r om t w ig s ;3 )s he l ls a ppea red t ob e v e ry g ood f o rd a t ing , b u t i nc er ta in a r ea s c au t ion s hou ld b e t a ken , s uch a s t h e C ook S t ra i t t o K a ikou ra c oa s ta l r e g ion w he re o cean ic u pwe l l ing

McCu l loch a nd T ro t te r ( 1975 :5 ) v i ewed moa b one a s a r e l iab le i n d ica to ro fi n i t ia l o ccupa t ion o f as i te , a nd b e l ieved

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F igu r e 3 . 3 . C ompa r ison o f r a d ioca rbon a ge s o n c ha r coa l , m a r ine s he l l a nd moa c o l lagen f r om N ew Z ea land a r chaeo log ica l s i tes b y McCu l loch a nd T ro t te r( 1975 )( b la ck a nd w h i te r e p roduc t ion o fo r ig ina lc o lou rg raph ) .

L aw r e commended t h a t o n ly i d en t if i ed c ha rcoa l f r om s ho r t l i ved s pec ie s o r y oung w ood b e u t i l i sed , b u t w a rned t h a t c on tam ina t ion w a s p o s s ib le f r om h um ic a c id s a nd t h e e f f ec t ive r emova l o f t h e se w as d i spu ted ( Law 1 9 8 1 :233 ) . A dd i t iona l ly , h e n o ted t h a t i d en t if ied c ha rcoa l s amp le s w e re o f ten m ade u p o f t h ree o r mo re s p ec ie s , a nd u n iden t if ied c ha rcoa l o f ten c on ta ined w ood u p t o 2 00 y ea r s o l d ( Law 1 981 :233 -234 ) . L aw ( 198 1 :234 ) b e l ieved t ha t m a r ine f i sh b one s hou ld b e e xce l len t f o r d a t ing a s l o ng a s p e lag ic f i sh w e re a vo ided a s t h ese s p ec ies c an f e ed o u t s ide o f N ew Z ea land w a te r s . H e a l so s ugges ted t h a t h uman b one s hou ld n o t b e u s ed b ecau se o ft h e p o ss ib ly h i gh ma r ine d i e t . Moa b one w a s s e en b y L aw a s a ccep tab le ( a s w e l l a s b one f r om a n ima l s w i th as o le d i e tc omponen t ) , b u th e n o ted t h a td oub t s o n t h e c on tam ina t ion o f c o l lagen w e re u n re so lved . F o r m a r ine m amma l s a nd b i rd s , L aw ( 198 1 :235) p ropo sed t h a t a n ima ls w h ich d e r ive t h e i r f ood f r om t r op ica l o r A n ta r c t ic s e a s s hou ld n o tb e d a ted .

t h a t i tw a s n o t p rone t oc on tam ina t ion f r om t h e a tmo sphe r e o r s u r round ing s o i l , o r a tr i sk o fc ompos i t iona l c hange . T he o n ly d i sadvan tage o f d a t ing moa b one w a s i t s a va i lab i l i ty f r om a r chaeo log ica ld epo s i t s . T hey c on s ide r ed m a r ine s he l l t o b e p rob lema t ic d ue t o g eog raph ica l v a r ia t ions i nr e se rvo i rc o r rec t ion s , a nd p o ten t ia l f o r r e c ry s ta l l isa t ion . C ha rcoa l a nd w ood w e r e v i ewed a s p o s se s s ing m any p rob lem s i nt e rm s o fs amp le h i s tory , s u ch a st h e u se o fr e l ic t imbe r s b y as i te 's i n hab i tan t s . McCu l loch a nd T ro t te r s ugge s ted t h a t c ha rcoa l a nd w ood s hou ld b e i d en t if ied b ef o r e d a t ing t o i s o la te s ho r t l ived m a te r ia l , b u t t h a t c ha r coa l w a s a t r i sk o f c on tam ina t ion b y h um ic m a te r ia l s( 1 975 :9 ) . F rom t h e i r a na ly s i s o fs i tes whe r e c ha rcoa l h ad b een d a ted a l ong s ide e i the r m a r ine s he l l o r m oa b one c o l lagen ( F igu r e 3 . 3 ) , McCu l loch a nd T ro t te r ( 1975 :1113 ) o b served t h a t c ha rcoa l d a te s w e re c ons i s ten t ly o l de r ( by o n a ve rage 2 00 y ea r s ) t h an d a te s o n t h ese ma te r ia ls . T hey c onc luded t h a t moa b one c o l lagen w a s t h e mo s t r e l iab le d a t ing ma te r ia l , f o l lowed b y m a r ine s he l l . T hey a l so s ugges ted t h a t c ha r coa l w a su n re l iab le ( McCu l loch a nd T ro t te r 1 975 :14 ) .

A nder son ( 1982 ) I n d i scu s s ing t h e c h rono logy o f e conom ic p a t te r n s i n A rcha ic s ou the rn N ew Z ea land , A nde r son ( 1982 :47 ) n o ted ( s ee F igu re 3 . 4 ) :

L aw ( 1981 )

" T he c hrono logy o ft h e s ou thern A rcha ic i sa tp r esen t i n as t a te o f s ome c onf us ion b ecau se r ad iocarbon d a t ing i n t h i s r eg ion s ome t ime s p roduce s e s t ima t e s u p t o 3 00 y ear s a pa r tf o r s im i lar l a y er s d epend ing o n t h e m a ter ia l p roce s sed ( T ro t t e r 1 968 , M cCu l loch a nd T ro t ter 1 975 ) . . . .T ow ha te x t en tt h i s d i scr epancy i sa r ea l o ne i su nknown s i nce f ew s i tes h av e b een c aref u l ly d a t ed b ya r ang e o fm a ter ia l s a nd m any o ft h e e ar l i e rd a tes w er e o b ta ined o n

L aw ( 198 1) p rov ided g u idance f o r r e sea rche r s i n s e lec t ing m a te r ia ls f o r r a d ioca rbon d a t ing . H e n o ted t h a t m a r ine s h e l l w as e xce l len t f o r d a t ing , g iv ing c on s i s ten t a nd r e p roduc ib le a ge s ( Law 1 98 1 :233 ) . A lso , t h a t c on tam ina t ion o f m a r ine s he l l s amp le s c ou ld b e i n ve s t iga ted u s ing x ray m e thod s , b u t Amph ibo la c r ena ta s hou ld n eve r b e d a ted ( Law 1 981 :233 ) .

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F igu re 3 . 4 . C ompa r i son o f s amp le t ype s u s ed t o d a te N ew Z ea land s ou thern A r cha ic a r chaeo log ica l s i t e s b y A nde r son ( 1982 ) . c ha rcoa l w e r e f o und ( Ande r son r e f e r r ing t o McCu l loch a nd T ro t te r 's ( 1975 :8 ) v i ew t h a t i n bu i l t a ge g r ea t ly a f f ec ted c ha r coa l r a d ioca rbon c h rono log ie s ) . S econd ly , A nde r son s ugge s ted t h a t i ft h e re w a s ama te r ia l s -dependen t d i f f e rence i n o b ta in ing r e l iab le r a d ioca rbon a ge s , t h en t h i s w a s n o t c ons is ten t , b ecause s ome s i tes s howed c h rono log ica l a g reemen t b e tween m a te r ia ls d a ted , a nd o t he r s d i d n o t ( Ande r son 1 982 :47 ) . B a sed o n t h e se t wo p o in t s , A nde r son

c harcoa lf rom w ood o fu nknown a ge ."

A nde r son ( 1982 :47 ) made t wo s i gn if i can t o bserva t ion s i nh i s d i scu s s ion o f t h e c ha rcoa l c h rono logy o f t h e s ou the rn A r cha ic . F i r s t ly , h e n o ted t h a t e ven t hough c ha r coa l r a d ioca rbon a ges f r om s ome A rcha ic s i t e s h ad b een d e r ived f r om s ho r t l ived ma te r ia l , t h e re w a s n o r e a son f o r r e jec t ion o ft h e c ha r coa l c h rono logy w h ich e x tended b ack t o8 00 -900 y ea r s B P u n t i l mo re d i ff icu l t p rob lems w i th t h e d a t ing o f

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T he S amp le T yp e D i lemma

( 1982 :47 ) b e l ieved t h a t c ha rcoa l r a d ioca rbon d a te s f o r t h e s ou the rn A r cha ic w e r e a ccep tab le .

g ood r e a sons t o p r ef e r s he l l t h an c ha r coa l f o r d a t ing t h e p r eh is to ry o fN ew Z ea land ( Law 1 984 :7 ) .

Mc F adgen ( 1982 )

T ro t te ra nd McCu l loch ( 1984 )

McFadgen ( 1982 ) i d en t if ied f ew p rob lems i n r a d ioca rbon d a t ing a r chaeo log ica l s i t e s u s ing m a r ine s he l l . B u t h e d id s ugge s tt h a t b ecau se d a te s o n ma r ine s he l l w ou ld o n ly b e a s a ccu ra te a s d a te s o n c ha rcoa l o r w ood , s he l l d a te s w i th s t anda rd e r ro r s l e s s t h an 5 0 y ea r s , s hou ld h ave t h e i r e r ro r s i n c rea sed t o 5 0 y ea r s ( McFadgen 1 982 :384 ) . F rom h i s r e ca lcu la t ion o ft h e N ew Z ea land m a r ine s he l l s t anda rd o f 3 30 y ea r s ( McFadgen 1 978 ) ( s ee C hap te r 5 ) , McFadgen p ropo sed t h a t a s t h e re h ad b een l i t t le c hange i n t h e r ad ioca rbon a c t iv i ty o f t h e m ixed l a ye r o cean i n t h e p a s t 1 000 y ea r s , t h e s ub t rac t ion o f af u r the r 55 y ea r s f r om t h e c ur ren t m a r ine s he l l s t anda rd ( now m ak ing t h e s t anda rd 3 85 y ea r s ) f o r s h e l l s l e s s t h an 1 000 y ea r s o ld , s hou ld p rov ide g ood c a lenda r d a te s ( McFadgen 1 982 :384 ) . McFadgen ( 1982 :384 ) n ex t c on s ide red p a i r ed c ha rcoa l a nd wood r ad ioca rbon d a te s f r om an umbe r o fa r chaeo log ica l s i tes t o i lus t ra te t h a t a ge d i f f e rence s b e tween c on tempo ra ry c ha rcoa la nd w ood d a te sw a sd ue t oi n bu i l ta ge .

T ro t te r a nd McCu l loch ( 1984 :7 18 ) m ade a c l ea r d i s t inc t ion w i th r e ga rd s t o t h e a ccuracy o f c ha r coa l , m a r ine s he l l a nd moa b one c o l lagen f o r d a t ing moa -hun t ing s i te s . T ro t te r a nd McCu l loch b e l ieved t h a t a l though c ha rcoa l w a s t h e m o s t c ommon m a te r ia l u sed f o rr ad ioca rbon d a t ing t h e se s i te s , t h e d ea th o ft h e w ood r a re ly d a ted t h e u se o f af i re ( 1984 :7 18 ) . Two p o s s ib le r e a sons f o r t h is w e re s ugges ted . F i r s t ly , t h a t w ood u sed f o rf u e l p robab ly o r ig ina ted f r om t r ee s l o ng d ead . S econd ly , t h a t e ven i fl i v ing wood w a s u sed , i t s i n ne r c o r e w ou ld b e o f d i f f e ren t a ge t han t h a t o f i t s o u te r w ood o r a s soc ia ted b r anche s . T hey a l so s ugge s ted t h a t c ha r coa l w a s h i gh ly s u scep t ib le t oc on tam ina t ion f r om s o i l c on s t i tuen t s , a s e xpe r ienced a t R edc l if f s a nd T a i R ua ( T ro t te r a nd McCu l loch 1 984 :7 18 ) . T hey b e l ieved t h a t moa b one c o l lagen w a s ab e t te rm a te r ia l f o rd a t ing moa -hun t ing s i te s a s i ta ppea r ed t o r e s i s t c on tam ina t ion f r om t h e g round o r t h e a tmo sphe r e , a nd h ad s hown v ery c on s i s ten t r e su l t s ( T ro t te r a nd McCu l loch 1 984 :7 18 ) . C oas ta l m a r ine s he l l w a s s e en a s p roduc ing s im i la r a ge s t o moa b one c o l lagen , b u t l a cked r ep roduc ib i l i ty ( T ro t te ra nd McCu l loch 1 984 :7 18 ) .

L aw ( 1984 ) I n 1 984 , L aw i n ve s t iga ted t h e r e l iab i l i ty o fm a r ine s he l l f o r r ad ioca rbon d a t ing N ew Z ea land a r chaeo log ica l s i te s . H e o b served t h a t e ven t h ough b y 1 984 , 1 9 1 d a te s e x i s ted o n s he l l f r om a r chaeo log ica l s i te s , t h i s m a te r ia l h ad n o t b een c ons ide r ed a c cep tab le b y a r chaeo log i s t s . L aw s ugge s ted t ha t t h is w a s b ecau se m a r ine s he l l h ad n o t b een s e en a s a c onven t iona l m a te r ia l t ou se , t h a t i th ad n o c a l ib ra t ion c u rve t o c o r rec t a ge s w i th , a nd t h a t t h e d i f f e ren t m a r ine s he l l c or rec t ion se mp loyed i nd i f f e r ing a r ea so ft h ew o r ld w e re n o t u nde r s tood b y a r chaeo log i s t s ( Law 1 984 :1) . L aw c ons ide red t h e c u r ren t m a r ine s he l l s t anda rd f o r N ew Z ea land ( 336 y ea r s ) ,a nd n o ted t h a t f r om t h e s even m odern s he l l s d a ted , n o r eg iona l d i f f e rence s i n r e se rvo i r a ge s c ou ld b e s e en ( Law 1 984 :3 ) . H e n o ted t h a t C h ione s t u tchbu ly i , P aph ie sa u s tra le , P aph ie ss ub t r iangu la tum , P aph ie s v en t r ico sum , H a l io t i s i r i s , T urbo s ma ragda , a nd P ro to thaca c ra s s i co s ta w e re p ref e rab le m a r ine s he l l s pec ie s f o r d a t ing , a nd t h a t Amph ibo la c r ena ta s hou ld b e a vo ided . L aw i l u s t ra ted t ha t ma r ine s h e l l d a te s f r om N ew Z ea land a r chaeo log ica l s i te s w i th m u l t ip le c u l tu ra l l a ye r s d i d s how s i te s t ra t ig raph ic a g reemen t , a nd t h a t m a r ine s he l l w a s r e p roduc ib le . H e t h en c ompa r ed a ge d i f f e rence s b e tween moa b one c o l lagen , r e se rvo i rc o r rec ted m a r ine s he l l , a nd c ha rcoa l d a te s f r om t h e s ame a r chaeo log ica l c on tex t a t an umbe r o fa r chaeo log ica l s i te s ( Law 1 984 :5 -6 ) . B y n o t ing t h e d i f f e rence i n y ea r s b e tween t h e s amp le t y pe s f o r e ach s i t e a nd a ve rag ing t h ese , L aw f ound t h a t moa b one c o l lagen a ge s a g reed c l o se ly w i th r e se rvo i rc o r rec ted s he l l d a te s , w i th am ean d i f f e r ence o f 0± 2 5 y ea r s . T he d i f f e rence s b e tween c ha rcoa l a nd r e servo i r c o r rec t ed s h e l l w e r e g r ea te r ( up t o 53 y ea r s ) , e ven t hough t h e mean d i f f e rence w a so n ly 8 3 ±3 6y ea r s . L aw c onc luded f r om h i s s t udy t h a t d ue t op rob lems s uch a s t h e S ue s s e f f ec t , c ha rcoa l a nd c o l lagen a ge s o fl e s s t h an 4 50 B P w e r e u s e le s s ( Law 1 984 :6 -7 ) , b u t s he l l w a s u s ef u l u p t o 2 50 y ea r s o rl e s s . A lso , t h a tt h e o f ten r ema rked d i f f e rence i n r ad ioca rbon a ge b e tween c ha r coa l a nd o t he r s amp le t ype s o f 2 00 y ea r s , w a s o n a ve rage o n ly 8 3 y ea r s , a nd t h e re w e re

T ro t te r a nd McCu l loch ( 1984 ) o b se rved t h a t moa b one c o l lagen a nd c ha r coa l d a tes f r om t h e s ame s i te , o n a ve rage , d ive rged i n a ge b y a s much a s 3 00 y ea r s . B a sed o n t h i s o b serva t ion a nd t h o se made a bove , t h ey p ropo sed , " I n d i scus s ing t h e d a te o f moa e x t inc t ion a nd t h e p a r t p l ayed b y m an i n t h a t e x t inc t ion , w e wou ld p r ef e r t o c ons ide r o n ly s amp le s o f moa b one c o l lagen" ( T ro t te r a nd McCu l loch 1 984 :7 18 ) . B u t d ue t ot h e l a ck o fc o l lagen d a te s f r om m oa h un te r s i t e s , T ro t te r a nd McCu l loch a l so e mp loyed m a r ine s he l l a ge s f o rt h e i ra na lys is , e xc lud ing d a te s f r om Amph ibo la a nd s he l l s amp le s n o ted b y t h e r a d ioca rbon l a bo ra to ry t o h ave b een a f f ec ted b y r e cry s ta l l isa t ion . A t t h e t ime o ft h e i r a na ly s i s , 2 7 moa b one c o l lagen d a te s a nd 2 2 ma r ine s h e l l a ge s w e r e a va i lab le f r om moa -hun te r s i t e s t h rough -ou t N ew Z ea land , b u t o n ly a h andf u l o f d a te s c ame f r om t h e N or th I s land ( T ro t te ra nd McCu l loch 1 984 : 7 18 ) . T ro t te r a nd McCu l loch ( 1984 :720 ) e xp la ined t h a t a l though moa b one c o l lagen a nd ma r ine s he l l d a t e s w e re b e l ieved t o b e r e l iab le , d i sc repanc ies d id o ccu rw h ich c onf l ic ted w i th t h e a r chaeo log ica l e v idence f r om s ome s i te s . T hey n o ted t h a t p rob lems w i th t h e r a d ioca rbon c h rono logy a t Wa i rau B a r a nd P apa towa i , w e r e p robab ly d ue t o t h e s amp le s b e ing s t o red f o r al o ng p e r iod o ft ime b ef o re b e ing u sed f o rd a t ing (Wa i rau B a r ) , a nd s amp le s b e ing c o l lec ted b y v a r iou sp eop le o ve r ap e r iod o f t ime f r om d i f f e ren t p a r t s o f t h e s i t e ( Papa towa i ) . D a te s f r om P apa towa i w e re i n g ene ra l c on s ide red d ub iou s a st h ey w e re ma in ly t a ken f r om c ha r coa l a nd moa b one c a rbona te , a nd t h e re w a s d i sag r eemen t b e tween ac ha rcoa l a nd r e se rvo i r c o r rec ted s he l l d a t e f r om t h e s ame l e ve l ( T ro t te r a nd McCu l loch 1 984 :720 ) . T hey n o ted t h a t o n ly o ne m oa b one c o l lagen d a te c ame f r om t h e N o r th I s land , a nd s ome o f t h e f ew s i t e s w i th s he l l d a te s c on ta ined s t ra t ig raph ic a noma l ies , s u ch a s t he F ox ton s i te ( T ro t te ra nd McCu l loch 1 984 :722 ) . Ande r son ( 1984 ) A nde r son d i scu s sed t h e r a d ioca rbon c h rono logy o f m oa e x t inc t ion i nS ou ther nN ew Z ea land . H eo b se rved :

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t h ey w e re f r om K a ikou ra ( Caugh ley 1 988 :250 ) . T h i s m e thod a ga in s howed c ha rcoa l w a s t h e o l de r m a te r ia l b y 2 4 1 ±4 2 y ea r s . C augh ley ( 1988 :250 ) b e l ieved t h is a na ly s i s s howed t h a t c ha rcoa l w a s o n a ve rage 2 40 y ea r s o l de r t h an d a te s o n m oa b one c o l lagen o rm a r ine s he l l . C augh ley ( 1 988 :250 ) d i d n o te , h oweve r , t ha t t h e d i f f e r ence o f 2 40 y ea r s m ay b e s ma l le r a s s ome c ha r coa l d a te s w e r e mo re r e cen t a nd m ay h ave b een s c reened f o rl o ng l ived s pec ie s .

" Many d a te sa r eu npub l i shed , a nd e xac td e ta i l s o ft h e ir p rov enance a r e u nknown . T he s ame may b e s a id o ft o o m any p ub l i shed d a te s . W o r se , t h er ei sf r equen t ly ad i scr epancy o fu pt o3 00 y ear s b e tween r ad iocarbon e s t ima te sf rom c harcoa ls amp l e sa nd t ho se f rom o t her m a t er ia l ss uch a sb one c o l lag en a nd m ar ine s he l l . T he d if f er ence i s i n con s i s t en t , a nd t h e c ause i sy e t u nc l ear ." ( And er son 1 984 :731 7 33 ) .

A nde r son ( 1 984 :733) n o ted t h a t w h i le c ha r coa l d a te s e x tended a sf a rb ack a s 1 000 y ea r s B P ,t h o se o n c o l lagen a nd r e se rvo i r c o r r ec ted ma r ine s he l l f e l l a r ound 8 00 y ea r s B P , a nd t h a t f o r s ome s i te s , d a te s o n c ha r coa l , c o l lagen , a nd m a r ine s h e l l s amp les f r om t h e s ame c on tex t w e re i n c h rono log ica l a g r eemen t ( Ande r son 1 984 :733) . A nde r son p r ef e r red c ha r coa l f o r d a t ing t h e moa -hun t ing p e r iod , b ecause r e cen t d a te s o n t h i s ma te r ia l w e re s pec ia t ed a nd p r oce s sed f o r s o i l c on tam ina t ion . H e a l so b e l ieved t h a t s u ch d a t e sw e r et h em o s ta ccu ra te w hen r e cons t ruc t ing c hange s i n v ege ta t ion f o r al o ca t ion t h rough t ime ( Ande r son 1 984 :733 ) .

I nc onc lus ion h e s t a ted : " W he ther c harcoa ld a t e sa r e mo r ea ccura te t h an c o l lag en a nd s he l l d a t e s c anno tp resen t ly b e d e term ined W ha t i sn o t i nd oub t i st h a t c o l lagen d a te s a nd m a r ine s he l l d a te s a r e c on s i s t en t w i th e ach o t her , a nd j o in t ly o r s epara te ly p rov id e am o r e p r ec i se r e la t ive c hrono logy t han d oe sc har coa l ." ( Caugh l ey 1 988 :250 ) .

C augh ley b e l ieved t h a t moa b one h ad a n a dvan tage o ve r c ha r coa l i nt ha t i ta c tua l ly d a ted a ne ven t ,t h ed ea th o f amoa , a nd i tw a so n ly t h is o ne e ven tt h a th ad t ob ed e te rm ined .

C augh l ey ( 1 988 )

A nder son ( 1989 )

C augh ley ( 1 988 ) c ons ide r ed t h e r ad ioca rbon c h rono log ie s f r om moa -hun t ing s i te s i nt h e No r th a nd S ou th I s land s i na n a temp tt ot r a ce t h ec o lon i sa t ion p a t ter no fN ew Z ea land . H i s s t udy i n c luded ac r i t ique o ft h e u se o fv a r ious s amp le t y pe s f o r d a t ing a r chaeo log ica l s i te s , a s se s s ing w ha t m a te r ia l w ou ld b e b e s t f o r d a t ing t h e movemen t o f t h e e a r ly P o lyne s ian s f r om t h e a r ea o ft h e ir f i r s t l a ndf a l l . H e b e l ieved t h a t c on tam ina t ion a nd f a l se a s soc ia t ion ( t he d ea th o f t h e s amp le b e ing d i f f e ren t f r om t h e e ven t b e ing d a ted ) w e re t h e m a jo rs ou r ce so fe r ro r i nd a t ing as ho r tp r eh i s to ry ( Caugh ley 1 9 88 :246 ) . F a l se a s soc ia t ion t o ok t h e f o rms o fR edepo s i t ion ; I n c lus ion ; M ix ing i np l ace ; a nd C on tempo ra ry d epo s i t ion o f s amp le s , b u t d i f f e ren t r ad ioca rbon a ge s . C augh ley a t t r ibu ted " c on tempo raneou sd epo s i t ion" a st h e m a in c ause o fl a rge a ge v a r ia t ion s b e tween c ha r coa l , r e servo i rc o r rec ted m a r ine s he l l a nd c o l lag en r a d ioca rbon d a te s . P rob lems a s soc ia ted w i th t h e v a r iou s s amp le t ype s i d en t if ied w e re i n bu i l t a ge f o r c ha r coa l a nd w ood , a nd y oung a ge s f o r b one c o l lagen ( Caugh ley 1 988 :247 ) .

A nde r son ( 1989 :172 173 ) a dd re s sed s amp le t y pe d i f f e rence s i nr a d ioca rbon d a te s f r om moa -hun te rs i te s . H e s t a ted t h a t : " One o ft h e l ong -s tand ing u ncer ta in t ie sc oncern ing a r chaeo log ica l c h rono logy i n N ew Z ea land i s w he ther t h e r e i s as y s t ema t ic d i f f erence i nt h e r ad iocarbon r e su l t s o b ta ined o n c ha r coa ls amp l e s a s o ppo sed t ot ho se o b ta ined o n b one c o l lagen a nd m a r ine s he l l ." ( And er son 1 989 :1 72 ) .

A nde r son ( 1989 :172 ) n o ted T ro t te r ( 1968 ) a nd T ro t te r a nd McCu l loch 's ( 1973 ) 3 00 y ea r d i f f e rence b e tween c ha rcoa l a nd ma r ine s he l l a nd c o l lagen r a d ioca rbon d a te s , C augh ley 's ( 1 988 ) 2 40 y ea r m ean d i f f e r ence , a nd L aw 's ( 1 984 ) a ve rage d i f f e rence o f8 3 y ea r s . B u t h e a l so n o ted t h a t a ts ome s i te s , s u ch a s Wa ima ta i ta i , t h e re w a s n o g r ea t d i ve rgence i na ge b e tween s amp le t ype s . A nde r son ( 1989 ) a ve r aged t h e r a d ioca rbon a ge s f o re ach s amp le t y pe f r om h i s m oa -hun t ing r a d ioca rbon c h rono logy , a nd i l us t ra ted t h a t a m ean d i f f e rence o f 2 6 y ea r s b e tween m a r ine s h e l l a nd moa c o l lagen , a nd 7 7 y ea r s b e tween m a r ine s he l l a nd c ha rcoa l e x is ted . F rom h i s a na ly s i s , h e c onc luded t h a t t h e d i f f e rence i n a ge b e tween moa b one c o l lagen o r m a r ine s h e l l a nd c ha rcoa l d a te s w a s a bou t 1 00 y ea r s ( Ande r son 1 989 :172 ) . A nde r son r e cogn ised t h a t i tw a s d i ff icu l t t o a s ce r ta in w hy t h e re w a s ad i f f e rence b e tween r a d ioca rbon a ge s o n v a r iou s s amp le t ype s , a nd w h ich m a te r ia l p rov ided a c on s is ten t a c cu ra te c h rono logy . H e o b se rved t h a t o ne o ft h e p rob lems w a s al a ck o f moa b one c o l lagen o rm a r ine s h e l l d a te s f r om t h e n or ther n Nor th I s land , s ou ther n S ou th I s land , o r i n land s i t e s ( Ande r son 1 989 : 173) . O the r p rob lems r e cogn i sed b y A nde r son w a s t ha t w ood w a s n o t i d en t if ied u n t i l 1 976 , t h a t c o l lagen d a te s may b e t oo y oung , a nd e s tua r ine s h e l l u sed c ommon ly f o r ma r ine s he l l s amp le s , m ay h ave s im i la r p rob lems t o f r esh w a te r s h e l l ( Ande r son 1 989 :173 ) . A nde r son c onc luded t h a t , " Un t i l m o r e i sk nown a bou t t h e se p rob lems . . . i t wou ld b e p ruden t t o l e ave t h e m a t te r o f p r ef e rence o pen a nd t r ea t s amp le t y pe s a s s epa ra te g roup s ." ( 1989 :173 ) .

C augh ley p r e sen ted r ad ioca rbon d a ta s how ing a l moa h un t ing s i t e s w i th b o th m a r ine s he l l a nd moa b one c o l lagen d a t e s ( s ee C augh ley 1 988 T ab le 4 ) . I n a n a na ly s i s o f t h i s d a ta , h e f o und t h a tt h e re w a s l i t t le d i f f e rence i na ge b e tween t h e se s amp le t y pe s f r om w i th in t h e s i te s , b u t t h a t d a te s f r om m a r ine s h e l l a nd moa b one c o l lagen v a r ied s i gn if ican t ly f r om a s soc ia ted c ha rcoa l a ge s . T h i s , h e n o ted , h ad a l so b een o b se rved b y T ro t te r ( 1968 ) a nd T ro t te r a nd McCu l loch ( 1 973 )( Caugh ley 1 988 :249 ) . C augh ley ( 1 988 ) c ompa r ed A nde r son 's ( 1983) l i s t o f c ha r coa l d a te s f r om moa -hun t ing s i te s w i th h i s o wn l i s t o f m a r ine s he l l a nd moa b one c o l lagen a ge s ( 3 5 d a te s f r om 1 0 s i t e s w h ich i n c luded 1 6 c ha r coa l a ge s , a nd 1 9 ma r ine s he l l a nd m oa b one c o l lagen d a te s ) . H e f o und t h e m ean o f o ne s amp le t y pe f r om as i te a nd c ompa r ed t h is w i th t h e m ean o f t h e o t he r s . T he g rea te s t a ge d i f f e rence f ound b e tween t h e r e se rvo i r c o r r ec ted a ge s w a s 2 64 ± 3 7 y ea r s f o r c ha r coa l . N ex t , h e p oo led t h e m a r ine s he l l a nd moa b one c o l lagen d a te s f r om t h e s i tes t o p roduce a m ean d a te o n t h o se m a t e r ia l s , a nd c ompa r ing t h i s w i th t h e p oo led m ean o f t h e c ha r coa l d a te s , s howed c ha r coa l t ob e 2 34 ± 4 4 y ea r s o l de r t h an t h e o t he rm a te r ia ls . F i na l ly , C augh ley t ook t h e t wo s e t s o fd a t es a nd p e rf o rmed ar e g r e s s ion a na ly s is o n t h ed i s tance s

A nder son a nd McGove rn -W i l son ( 1990 ) A nde r son a nd McGover n -W i lson ( 1990 :43 -45 ) i n ve s t iga ted t h e u se o fd i f f e r ing s amp le t ype s f o rr a d ioca rbon d a t ing moa h un t ing s i te s , wh i le c r i t iqu ing C augh ley 's ( 1988 ) a na ly s is o f m oa -hun t ing r ad ioca rbon d a te s .

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F igu r e 3 . 5 . A nde r son 's ( 1989 ) c umu la t ive p robab i l i ty c u rve s o f r a d ioca rbon d a te s o n d i f f e r ing s amp le t ype s f r om m oa -hun t ing s i te s . t h an c ha r coa l f o r d a t ing moa -hun t ing s i t e s a s t h is m a te r ia l a c tua l ly d a ted t h e c u l tu ra l e ven t . T hey e xp la ined t h a t c ha r coa l d i d h ave p rob lem s w i th i n bu i l t a ge , b u t s i nce 1 976 t h e I GNS h ad r o u t ine ly s c reened c ha r coa l s amp le s b ecau se o f t h i s p rob lem . T hey n o ted t h a t m oa b one c ou ld a l so b e p rone t o at y pe o fi n bu i l t a ge a st h e b one o fb i rd s l o ng d ead m ay b e b rough t t o t h e s i te f o r p r oce s s ing , a s a r gued b y M i l lene r ( 198 1) , P r icke t t ( 1987 ) , N icho l ( 1988 ) a nd McFadgen ( 1 987 ) . A nde r son a nd McGove rn -W i l son ( 1990 :44 )b e l ieved t h a tt h is o ccur r ence w ou ld n o tb e o fg r ea t c oncer n f o r S ou th I s land s i tes , b u t w a s s t i l l p o ten t ia l ly a p rob lem a sb one c an s u rv ive f o r l o ng p e r iod s o ft ime i nd ry r eg ion s . T hey s ugges ted t h a t m a r ine s he l ls c ou ld a l so b e c on tam ina ted t og i ve o l de r a ge s a s o b se rved b y McFadgen

A nde r son a nd McGove rn -W i lson ( 1990 :43 ) o b se rved t h a t a l though C augh ley b e l ieved o ne s amp le t y pe c ou ld n o t b e p r ef er red o ve r a no the r i nr ef lec t ing t h e c h rono logy o fN ew Z ea land p r eh i s to ry , C augh ley t h en s e t o u t t o i l us t ra te t h e re w e re d i s t inc t ive a ge d i f f e rence s b e tween c ha rcoa l , m a r ine s he l l a nd m oa b one c o l lagen r ad ioca rbon d a te s . T hey n o ted t h a t A nde r son 's ( 1989 ) ( s ee a bove ) a na lys is f o und d i f f e rence s i n a ge b e tween c ha rcoa l d a te s a nd d a te s o n m a r ine s he l l a nd m oa b one , w e re s i gn if ican t ly l e ss t h an t h e 2 40 y ea r s p ropo sed b y C augh ley ( Ande r son a nd McGove r n W i lson 1 990 :43 ) . A nde r son a nd McGove rn -W i lson ( 1990 :44 ) a l so d i sag reed w i th C augh ley 's o b se rva t ion t h a t c o l lagen d a te s w e re b e t te r

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v a r ia t ions i n moa d i e t ( wh ich s hou ld b e ma in ly aC 3 p l an t d i e t ) , i n adequa te s amp le p r epa ra t ion , o r d i agene t ic a t tack f r om b ac te r ia w h ich i n t roduce n ew o rgan ic c ompound s t o t h e c o l lagen w h i le i n t h e g round ( Ande r son 1 99 1 :777 ) . A nde r son o b served t h a t t e s t s o f s amp le i n teg r i ty f o r b one s uch a s " c ompa ra t ive d a t ing o f t h e a m ino a c id f r ac t ions i n t h e c o l lagen , e xam ina t ion o f c a rbon :n i t rogen r a t io s ( t he n orma l r a nge i s2 : 9 -3 :6 ) a nd t h e m ea su remen t o f f l uo r ine l e ve l s " h ad n o t b een u nder taken o n ar ou t ine b a s is b y N ew Z ea land l a bo ra to r ie s ( Ande r son 1 99 1 :779 ) . F ac to r s c on t r ibu t ing t o i n con s i s ten t r e su l t s i n h i s v i ew i n c luded v a r iab le c o l lagen c oncen t ra t ions a nd c hang ing t r ea tmen t s t o e x t rac t c o l lagen ( u s ing HC 1 , p ho spho r ic a c id , a nd n ow 0 . 6N HC 1 ) ( Ande r son 1 99 1 :779 ) . M ine ra l isa t ion c aus ing y oung c a rbon t o b ecome i n corpo ra ted f r om t h e s u r round ing e nv i ronmen t i n to t h e b one c o l lagen w a s a no the r s ou r ce o f d i ff i cu l ty i d en t if ied b y A nde r son ( 199 1 :779 ) . A nde r son ( 199 1 :779 ) a l so s u spec ted t h a t t h e re w e re moa b one c o l lagen d a te s o n b one n o t a s soc ia ted w i th b u tche r ing a c t iv i t ie s , b u t f r om n a tu ra l s ub -f o s s i l d epo s i t s . A nde r son ( 199 1 :779 ) b e l ieved t h a t b ecause o f t h e se p o ten t ia l p rob lems , r a d ioca rbon d a te s o n moa b one c o l lagen c ou ld n o t b e r e l ied u pon ( Ande r son 1 99 1 :779 ) .

( 1987 ) a tA voca P o in t , K a ikou ra ( Ande r son a nd McGover n W i lson 1 990 :44 ) . A nde r son a nd McGove rn -W i lson ( 1990 :44 ) c ha l lenged C augh ley 's ( 1 988 :249 ) a s ser t ion t h a t m a r ine s he l l a nd c o l lagen d a te s b o th p roduced v e ry s im i la r a ge s , b y c on s ide r ing A nde r son 's ( 1989 ) C umu la t ive P robab i l i ty C u rve s ( s ee F i gu re 3 . 5 ) . T hese c urve s c ompa red c ha rcoa l , m oa b one c o l lagen a nd r e se rvo i r c or rec ted m a r ine s he l l r a d ioca rbon d a te s f r om moa -hun t ing s i te s . T he c u rve s s howed c ha r coa l d a tes n o rma l ly d i s t r ibu ted s im i la r ly i nt ime a s moa b one c o l lagen d a te s , whe rea s t h e m a r ine s he l l a ge c u rve w a s v a r ied . A nde r son a nd McGove rn -W i lson ( 1990 :44 ) s ugge s ted t h is i lus t ra ted t h a t c ha r coa l w a s n o t " t he o dd m an o u t " a s o b se rved b y C augh ley , a nd t h a t t h e r e w e re m any o t he r r e a son s f o r c ha l leng ing t h e u se o fv a r iou s s amp le t y pe s , s uch a s c hange s i n c oun t ing s t anda rd s , p roce s s ing m e thod s , o r d a t ing t e chn ique e t c ( Ande r son a nd McGover n -W i l son 1 990 :45 ) . A nde r son a nd McGove r n W i lson ( 1990 :45 )c onc luded : " N ever th e l e s s i ti sn o t o ur i n ten t ion t od i spu te t h e v a l id i ty o fd a t e s o n a ny p a r t i cu la r s amp le t y pe ; r a ther i ti s t o e mpha s i se t h a t g enera l u nc e r ta in ty , f or o ne r ea son o r a no ther , a bou t a l l a rchaeo log i ca l r ad iocarbon d a tes . . .r end er s i n va l id t h e c ho ice o f o ne s er i e s o v er a no ther a s t h e d a ta b a s e o n w h ich t ot e s t ab road c hrono log i ca lh ypo the s i s ."

t ua tua •

A nd er son ( 1 991 )

c ock le

N2 1 347

A nde r son ( 1 99 1 :768 ) d i scus sed t h e a ccep tab i l i ty o f p a r t icu la r s amp le t ype s f o r r ad ioca rbon d a t ing i nh i s p ape r o n t h e f i r s tc o lon isa t ion d a te o fN ew Z ea land . H e n o ted t h a t s e t s o f d a te s f r om t h e s ame a r chaeo log ica l c on tex t s how c ha r coa l t ob e c ons is ten t ly o l de r t h an m a r ine s he l l a nd b one c o l lagen b y s e ve ra l h und red y ea r s , a s o b se rved b y T ro t te r ( 1968 ) , R af t e r e ta l . ( 1972 ) , McCu l loch a nd T ro t te r ( 1975 ) , L aw ( 1984 ) , C augh ley ( 1988 ) , A nde r son ( 1989a ) , a nd A nde r son a nd McGover n -W i l son ( 1990 ) ( Ande r son 1 99 1 :768 ) . A nde r son ( 199 1 :777 -782 ) t h e ref o r e a dd re s sed p rob lems a s so c ia ted w i th t h e v a r iou s s amp le t y pe s u sed i n r a d ioca rbon d a t ing N ew Z ea land p r eh is to ry , t o t r y t o d e term ine w h ich s amp le t y pe w a sr e l iab le .

4 Ni 1 251

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NZ 6 83

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F i gu re 3 . 6 . P rob lems i n r a d ioca rbon d a t ing s he l lf i sh o f d i f f e r ing s pec ie s f r om t h e F ox ton a r chaeo log ica l s i t e ( r ad ioca rbon d a te s h ave b een c a l ib ra ted )( f rom A nde r son 1 99 1 :779 ) .

A nde r son s ugge s ted t h a t t h e re w e r e t wo a r ea s o fc once rn i n d a t ing m a r ine s he l l . T he f i r s tw a st h a t mo s t s amp le s u sed f o r d a t ing w e r e e s tua r ine s pec ie s s uch a s c ock le s ( Au s t rovenu s s t u tchbu ry i ) , w h ich m ay h ave c ome f r om c a tchmen t s a s soc ia ted w i th c a lc ium c a rbona te o fi n f in i te r a d ioca rbon a ge ( Ande r son 1 99 1 :777 ) . T h i s w a s s hown b y McFadgen 's ( 1972 , 1 978 ) s t ud ies o n d i f f e rence s b e tween t h e r a d ioca rbon a ges o f c ock le a nd t u a tua ( Paph ie s s ub t r iangu la tum ) f r om t h e F ox ton a r chaeo log ica l s i te ( F igu re 3 . 6 ) . T he s e cond c au se o f c once rn w a s t h e u se o f s p ec ie s w h ich o t he rw ise m ay b e r e l iab le , s uch a s s ub t ida l r o cky s ho re s he l lf i sh , b u t w h ich c ame f r om a r ea s o fd eep o cean ic u pwe l l ing a s soc ia ted w i th l i me s tone s t ra ta , s uch a s a t A voca P o in t , K a ikou ra ( Ande r son 1 99 1 :777 ) .

A nde r son 's c once rn s w i th d a t ing c ha rcoa l c ame f r om t h ree m a jo ra r ea s -i n bu i l t a ge ; t h e i d en t if ica t ion o ft r ee s p ec ie s f o r d a t ing ; a nd t h e c a ref u l u se o ft w ig s . H e e mpha s i sed t h a t a l c ha r coa l s hou ld b e i d en t if ied a nd c a ref u l ly s e lec ted p r io r t o d a t ing ( 199 1 :779 -78 1 ; s e e C hap te r4 ) . F rom h i s p r e sen ta t ion o fp rob lems a s soc ia ted w i th t h e d a t ing o fm a r ine s he l l , m oa b one c o l lagen , a nd c ha r coa l , A nde r son s t a ted , " t he se v a r iou s a r gumen t s [ s how ] t h a t t h e re i sn o s y s tema t ic m a rg in o fe r ro r b e tween r a d ioca rbon d a te s o n s amp le s o fd i f f e ren t t y pe " a nd t h a t s ou r ce s o f e r ro r c an b e d ue t o l o ca l c ond i t ion s ( Ande r son 1 99 1 :78 1) . H e c onc luded , " S ince w e c anno t b e s u re w h ich d a te s e xh ib i t s i gn if ican t e r ro r s , o rt ow ha t e x ten t , t h e r e i sn o p o in t i nd we l l ing o n t h e ma r ine s he l l a nd b one c o l lagen c h rono log ie s ( Tab le 1 ,F igu re 6 ) . T hey a r e b road ly s im i la r t o t h e c ha r coa l c h rono logy b u t d i sc lo se g r ea t v a r iab i l i ty ." ( Ande r son 1 99 1 :781-782 ) .

A nde r son ( 1 99 1 :777 -779 ) n ex t c on s ide red p rob lems a s soc ia ted w i th d a t ing moa b one c o l lagen . T he f i r s t s ou r ce o f p o ten t ia l e r ro r w a s t h e a moun t o f p o s s ib le f r ac t iona t ion w h ich c ou ld h ave a f f ec ted t h e s amp le s . H e n o ted t h a t a l though 8 "C l e ve ls c ou ld b e d e te rm ined f o r b one s amp le s , d e te rm in ing w ha t a f f ec t v a r ia t ions i nf r ac t iona t ion m ean t i n d a t ing , w a s p rob lema t ic . T he se c ou ld r ef lec t a ny th ing f r om

F an k hau ser ( 1992 ) F ankhau se r ( 1992 ) d a ted Umu t i i nS ou th C an te rbury u s ing T he rmo lum ine scence ( TL ) a nd r ad ioca rbon d a t ing t o

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l i ved s pec ie s , a nd t h e n umbe r o f c ha rcoa l a nd m a r ine s he l l r ad ioca rbon a ge s u s ed f o r c ompa r ison w a s q u i te l a rge ( 24 c ha rcoa l a nd 4 1 m a r ine s he l l ) . N o o t he r p r ev ious s t ud ie s h ad s uch e x tens ive a nd w e l l p rovenanced d a ta .

d e term ine t h e s e t t lemen t t ime o f t h e S ou th I s land . T h ir ty f ou r r a d ioca rbon d a te s w e re o b ta ined o n i d en t if ied c ha rcoa l ( ma in ly P odoca rp s p . ) f r om t h e se p r eh is to r ic s t ruc tu re s ( Fankhause r 1 992 :29 -30 ) . F ankhau se r( 1992 :37 ) b e l ieved t h e r ad ioca rbon d a te s i n d ica ted t h a t S ou th C an te rbu ry a nd S ou thern N ew Z ea land w e re c o lon ised b y c a . 1 275 AD , b u t t h a t i n bu i l t a ge h ad c aused l a rge v a r ia t ion s i nt h e c ha rcoa l a ge s d e r ived f r om t h e Umu t i . C ons ide r ing a l te rna t ive s t o u s ing c ha rcoa l f o rd a t ing b ecau se o fi n bu i l ta ge , h e a sked " I s t h e r e d a t ing e v idence o t he r t h an r a d ioca rbon c ha rcoa l d a te s w i th w h ich t oa s se s st h e p r eh is to r ic s e t t lemen to fC an te rbu ry a nd t h e S ou the rn S ou th I s land? " ( Fankhau se r 1 992 : 3 4 ) . I n a nswe r ing t h is q ue s t ion , F ankhau se r e xc luded c ha rcoa l f o r a r chaeo log ica l d a t ing , n o t ing t h a t p a s t e xpe r ience h ad s hown i tt o b e u n re l iab le f o r d a t ing s i te s , a s s hown b y McCu l loch a nd T ro t te r ( 1975 ) , McFadgen ( 1982 ) , a nd L aw ( 1984 ) . T he se s t ud ie s s howed t h a t t w ig s c an b e r i sky t o u se , a nd e ven w i th i d en t if ied w ood f r om s hor t l ived s p ec ie s , t h e re w a s s t i l l a n u nknown i n bu i l ta ge ( Fankhause r 1 992 :34 ) .

D ISCUSS ION AN D CONCLUS IONS F ind ing a Re l iab le S a mp le Type f or Rad iocarbon Dat ing New Z ea land Archaeo logy I n t h is r e v iew , Ih ave e xam ined p a s t l i t e ra ture c oncer n ing d i f f e rence s i nr a d ioca rbon d a te s b e tween s amp le t y pe s f r om a r chaeo log ica l c on tex t s , a nd t h e r e l iab i l i ty o f v a r ious ma te r ia l s f o r d a t ing N ew Z ea land p r eh is to ry . Two a r ea s o f c oncern a r e a ppa r en t . T he f i r s t r e la te s t o t h e r e l iab i l i ty o f p a r t icu la r s amp le t ype s f o r d a t ing . V a r iou s p rob lems i d en t if ied i n c lude i n bu i l t a ge i n w ood , t h e u se o f b one c a rbona te a nd c o l lagen , a nd p o ten t ia l r e c ry s ta l l isa t ion o f ma r ine s he l l . S econd ly , t h e r e i s ac once rn a bou t m i s a s soc ia t ion o fs amp le a nd e ven t .

F ankhause r ( 1992 :35 ) t h en c on s ide red t h e u s e o f m a r ine s he l l a nd moa b one c o l lagen f o r d a t ing s ou ther n moa h un t ing s i tes ( u s ing d a te l i s t s f r om t h e se s i te s s u ch a st h a t o f A nde r son a nd McGove rn -W i lson ( 1990 ) ) , a nd o b served t h a t e ven t h ough t h e se m a te r ia ls a ppea red t o b e m o re r e l iab le t h an c ha rcoa l , p rob lems h ad b een n o ted w i th t h e i r u se . H e a l so n o ted t ha t mo s tm a r ine s he l la ges b e ing l e s st h an 6 50 c a l y ea r s B P may b e a n i s sue o f c once rn t o p r eh is to r ian s ( Fankhau se r 1 992 :35 ) .

I ti sc l ea r f r om t h is l i t e ra tu re r e v iew t h a t a r chaeo log is t s a r e d iv ided o n t h e r e l iab i l i ty a nd u sef u lne s s o fv a r iou s m a te r ia ls a va i lab le i n a r chaeo log ica l d epo s i t s f o r d a t ing ( Tab le s 3 . 3 a nd 3 . 4 ) . N o p a r t icu la r s amp le t ype h a s b een u n ive r sa l ly a ccep ted e i the rf o r i t sp o s t -depo s i t iona l s t ab i l i ty o rd eg ree o f a s soc ia t ion w i th t h e e ven t t o b e d a ted . C an a ny f i rm c onc lu s ion s b e d r awn f r om t h e l i t e ra tu r e a s t o t h e b e s t ma te r ia l f o r a r chaeo log ica l d a t ing? T oo f ew s t ud ie s h ave b een made t o s a t i sf ac to r i ly a nswe r t h i s q ue s t ion , a nd o f ten r ad ioca rbon a ge s o n ap a r t icu la r s amp le t ype h ave b een r e jec ted b y a r chaeo log i s t s b a sed e i the ro n s t ud ie s w h ich h ave b een i ne r ro r , o ro n u n sub s tan t ia ted t h eo ry .

I n t h e l i gh t o f h i s c ha rcoa l r a d ioca rbon d a te s , F ankhau se r a dvoca ted t h e u s e o f T L f o r d a t ing N ew Z ea land a r chaeo log ica l s i t e s . H e b e l ieved t h a t T L d a t ing c ou ld p rov ide mo re a ccu ra te r e su l t s t h an r a d ioca rbon d a t ing , e spec ia l ly w hen a temp t ing t o r ad ioca rbon d a te c ha rcoa l b ecause o ft h e p rob lem o fi n bu i l t a ge ( Fankhau se r 1 992 :36 ) . F ankhause rp ropo sed t h a t T L w ou ld s e em t ob e a n i mpo r tan t a nd s e ns ib le a l ter na t ive t o t h e d a t ing o f c ha r coa l , a s g reywacke o ven s t one s w e re c ommon i n a r chaeo log ica l s i te s . H e c onc luded t h a t a l though m a r ine s he l l m ay b e mo re r e l iab le f o r r ad ioca rbon d a t ing t h an c ha rcoa l , w he re m a r ine s he l l i sl a ck ing f r om as i te , T L d a t ing m ay p rov ide r e l iab le d a te s , a nd s o a i d i nr e so lv ing t h e p r eh i s to r ic s equence o f N ew Z ea land ( Fankhau se r 1 992 :37 ) .

H igham 's ( 1993 ) r e sea rch o n r ad ioca rbon d a t ing N ew Z ea land p reh is to ry f o und f ew p rob lems i n t h e d a t ing o f c ha r coa l a nd ma r ine s h e l l f r om a r chaeo log ica l c on tex t s . T h i s w a s t h e f i r s t d e ta i led s t udy w h ich l o oked a tt h e d i f f e rence s b e tween i d en t if ied c ha rcoa l a nd ma r ine s he l l a ge s , a nd c on s ide red t h ree N ew Z ea land a r chaeo log ica l s i t e s i n t h e a na ly s is ( s ee C hap te r s 4a nd 5 ) . H igham ( 1993 )u s ed t h en ew

T he mo s t s i gn if ican t i n ves t iga t ions t h a t h ave b een u nder taken , w e re t h o se b y T ro t te r ( 1967c , 1 968 ) , R af te r e t a l . ( 1972 ) , M cCu l loch a nd T ro t te r ( 1 975 ) , L aw ( 1984 ) , C augh ley ( 1988 ) , a nd A nde r son ( 1989 ) ( e xc lud ing H igham 1 993 , s ee b e low ) w he re a ge d i f f e rence s b e tween v a r iou s s amp le t ype s f r om t h e s ame a r chaeo log ica l c on tex t s w e re c ompa red . T he se c ompa r i sons w e re u nde r taken i nt wo w ay s . T he f i r s t m e thod i n vo lved c a lcu la t ing d i f f e r ence s i n r ad ioca rbon a ge b e tween s amp les t ype s f r om e ach o f t h e a r chaeo log ica l s i t e s b e ing a na ly sed . A l l t h e a ge d i f f e rence s f r om t h e s i te s w e r e t h en a ve raged t op roduce a n o ve ra l l a ge d i f f e rence b e tween e ach s amp le t ype ( T ro t te r 1 967c , 1 968 ; R af te r e ta l . 1 972 ; McCu l loch a nd T ro t te r 1 975 ; L aw 1 984 ) . T h is m e thod t o ok i n to a ccoun t s i te h i s to ry a nd c u l tura l i n terp re ta t ion . T he s e cond m e thod u sed l i s t s o fr ad ioca rbon d a tes f r om s i te s w h ich h ad mu l t ip le m a t e r ia l s d a ted , d e r ived am ean a ge f r om t h e t o ta l n umbe r o fd a t e s f o r e ach s amp le t ype , a nd t h en c ompa red t h e se means t of i nd t h e v a r ia t ion i n r ad ioca rbon a ge f o r e ach s amp le t y pe ( Caugh ley 1 988 ; A nde r son 1 989 ) .

mode l led ma r ine c a l ib ra t ion c u rve a nd AR d eve loped b y S tu ive ra nd B raz iuna s( 1993) , a nd s aw t h a tt h ed i f f e rence s i n c a l ib ra ted a ge b e tween m a r ine s he l l a nd c ha r coa l d a te s w a s s ma l l , t h e o n ly a noma l ie s b e tween d a te s b e ing f r om o ne s i t e wh ich w a s l a te r f o und t o h ave s uf f e red f r om p o s t d epo s i t iona l d i s t u rbance ( H igham p e r s . c omm . ) . H igham ( 1993) c onc luded f r om h i s s t udy t h a t h e h ad n o p r ef e r ence f o r o ne s amp le t y pe o ve r a no the r , b e l iev ing t h a t t h i s w a s a s i te s pec if ic i s sue . T he i mpo r tan t a spec t r ega rd ing H igham 's s t udy , w a s t ha t a l l t h e c ha rcoa l u sed w a s i d en t if ied t os ho r t -

B o th t h e se m e thod s o fc ompa r ison p roduced a ge d i f f e r ence s b e tween c ha r coa l a nd r e se rvo i r c o r rec ted m a r ine s he l l f r om a s g rea t a s 3 00 y ea r s t o a s l i t t le a s 7 7 y ea r s , a nd b e tween r e servo i r c o r r ec ted m a r ine s he l l a nd m oa b one c o l lagen , f r om 2 6 y ea r s d own t o 0y ea r s . I tc an b e s e en , t h e ref o re , t ha t b o th t h e m e thodo log ie s p roduced v e ry d i ve r se r e su l t s . T h is w a s b ecause e a ch m e thod c on ta ined f u ndamen ta l e r ro r s , wh ich r e su l ted i n i n accu ra te a pp ra isa l s o f r a d ioca rbon a ge d i f f e rence s b e tween c ha rcoa l a nd ma r ine s he l l a nd b one c o l lagen s amp le t y pe s .

H igham ( 1993 )

2 4

C HAPTER 3

T he S amp le T yp eD i lemma C harcoa l

Mar ine s he l l

B one c o l lagen

N

Y

Y

T ro t te r( 1 967c , 1 968 ) L aw ( 1 97 1) R af te re ta l . ( 1972 )

Y +

Y

Y

N

Y

Y *

Y

Y

,

Y +

G ran t -Tay lo r( 1974 ) McCu l loch a nd T ro t te r( 1975 ) L aw ( 1 98 1)

N

Y

Y

Y+

Y

Y *

A nde r son ( 1982 )

Y

?

?

L aw ( 1 984 )

N

Y

N

N

Y

Y

A nde r son ( 1984 )

Y +

?

?

C augh ley ( 1988 )

N

Y

Y

Y+ Y+

?

?

?

? ?

F ankhau se r( 1992 )

Y+ N

? Y

N

H igham ( 1993 )

Y +

Y

?

T ro t t e ra nd McCu l loch ( 1984 )

A nde r son ( 1989 ) A nde r son a nd McGove rn -W i l son ( 1990 )

-

A nde r son ( 199 1)

T ab le 3 . 3 . S umma ry o fo p in ion s o n t h e r e l iab i l i ty o ft h e t h ree m a in s amp le s t ype s u sed f o r r ad ioca rbon d a t ing N ew Z ea land a r chaeo log ica l s i te s . ( y =r e l iab le ; y + =r e l iab le i ft w ig s a r e u sed ; y * =r e l iab le b u t c an b ea f f ec ted b y c on tam ina t ion ; n= n o t r e l iab le ; ?= r e l iab i l i ty u ndec ided e i the r d ue t o u n r e so lved i s sue s s uch a s c on tam ina t ion ,o rf u r the rr e sea rch r e qu i red ) .

C u l tura l e ven t b e ing d a ted

C harcoa l

Mar ine s he l l

B one c o l lagen

G ran t -Tay lo r( 1974 )

Moa -hun t ing

N

N

Y

M cCu l loch ( 1 975)

T ro t te r

Moa -hun t ing

N

Y

Y

McCu l loch

Moa -hun t ing

N

N

Y

A nde r son ( 1 984 )

Moa -hun t ing

Y +

N

N

C augh ley ( 1 989 )

C o lon isa t ion o f N ew Z ea land

N

Y

Y

A nde r son ( 1 99 1)

C o lon i sa t ion o f N ew Z ea land

Y+

?

?

T ro t te r ( 1 984 )

a nd

a nd

T ab le 3 . 4 . S umma ry o fo p in ion s o n s amp le t y pe r e l iab i l i ty b a sed o n w ha t ma te r ia l mo s t i k e ly d a te s t h e c u l tu ra l e ven t b e ing i n ve s t iga ted . ( y =r e l iab le ; y + =r e l iab le w hen t w ig s a r e u sed ; n= n o t r e l iab le ; ?= r e l iab i l i ty u ndec ided ) .

T he mo s t n o tab le e r ro r i n t h e i n ve s t iga t ions o f T ro t te r ( 1967c , 1 9 68 ) , R af te r e ta l . ( 1972 ) , McCu l loch a nd T ro t te r ( 1975 ) a nd L aw ( 1984 ) ,w a st h a tc ha r coa l u sed f r om t h e s i te s i nt he c ompa r i sons w a s n o t i d en t if ied t ot r ee s pec ie s . Of t en t h e o bse rva t ion w a s m ade t h a t t h e c ha r coa l u sed f o r d a t ing mus t h ave b een f r om r e l ic w ood , s uch a s d r if t w ood , w h ich a ccoun ted f o r t h e c ha r coa l d a te s b e ing h und red s o f y ea r s o lde r t h an t h e m a r ine s h e l l o r moa b one c o l lagen a ges . B u t b ecause t h e c ha rcoa l u s ed i nt h e se s t ud ie s w a s u n iden t if ied , t h e s amp le s d a ted w e r e a t h i gh r i sk o f b e ing a f f ec ted b y i nbu i l t a ge . As e cond p rob lem w i th t h e se s t ud ie s w a s t h e p os s ib i l i ty t h a t c ompa ra t ive s amp le s m ay n o t h ave b een c o l lec ted f r om t h e s ame s t ra t ig raph ic l a ye r s w i th in a s i te . T he o n ly s t udy o f t h is k i nd w h ich h a s b een u nder taken c or rec t ly w he re c ha rcoa l w a s i d en t if ied t o s ho r t l ived s pec ie s , a nd t h e p rovenance o f t h e d i f f e ren t s amp le t ype s b e ing c ompa r ed w a s t h e s ame , w a s b y H igham ( 1993) . A s

e xp la ined a bove , H igham f ound l i t t le d i f f e r ence b e tween h i s p a i red c ha r coa l o rm a r ine s he l l r a d ioca rbon a ges . T he l a te r s t ud ie s b y C augh ley ( 1988 ) a nd A nde r son ( 1 989 ) i n vo lved s t ra igh t s t a t i s t ica l c ompa r ison s o fl i s t s o fd a t e s . A n o bv iou s p rob lem w i th t h e se a na lyse s w a s t h a t t h ey w e re g ene ra l c ompa r i sons o f d a te s w i thou t r e ga rd t o t h e s t ra t ig raph ic r e la t ionsh ip o ft h ed a te so rt h es i te h i s to ry . O the r s i gn if ican t f a c to r s a l so n o t c on s ide r ed b y a ny o ft h e c ompa ra t ive s t ud ie s a bove ( e xc lud ing H igham 1 993 ) , w a s t h e N ew Z ea land Ma r ine S he l l S t anda rd u sed b y t h e I GNS l a bo ra to ry h ad c hanged o ve r t h e y ea r s , a nd t h e i r m e thod t o c a lcu la te r e se rvo i r c o r rec ted m a r ine s he l l r a d ioca rbon d a t e s h ad a l so c hanged . T h is i s b e s t i l u s t ra t ed a t L ocke rb ie 's P ounawea s i te a bove . T he o n ly s t udy t h a t r e f e r red b r ief ly t o ac hang ing m a r ine s he l l s t anda rd w a s A nde r son ( 199 1 :782 ) . T he d i f f e rence s i nr a d ioca rbon a ge b e tween m a r ine s he l l a nd

2 5

CHAPTER 3

T he S amp le T ype D i lemma

L ab N o .

S amp le T ype

P rovenance

A s soc ia ted A r tef ac t s a nd F auna

CRA

NZ -682

C ha rcoa l s p .?

L aye r2

Moa b one

7 28 ±4 2

NZ -684

C ha rcoa l s p .?

L aye r2

Moa b one

5 17 ±6 0

NZ -685

C ha rcoa l s p .?

L aye r2

Moa b one

1 77 ± 13

NZ -683

A u s t rovenu s s t u tchbury i

L aye r2

Moa b one

1 053 ± 5 8

NZ 1250

P aph ie s s ub t r iangu la tum

L aye r2 ,S he l l L en s 3

Moa b one

6 95 ± 5 4

NZ 1251

A u s t rovenu s s t u tchbury i

L aye r2 ,S he l l L en s4

E u ropean c u l tu ra l m a te r ia l

169 ± 7 0

NZ 1347

A u s t rovenu s s t u tchbury i

L aye r2 ,S he l l L ens 4

E u ropean c u l tu r a l m a te r ia l

159 ±4 8

NZ 1349

A u s trovenu s s t u tchbury i

L aye r 1 ,S he l l L en s 1

Moa b one

1 093 ± 5 2

NZ 1479

A u s t rovenu s s t u tchbury i

L aye r2 ,S he l l L en s 3

Moa b one

9 84 ± 5 6

NZ 1480

P aph ie s s ub t r iangu la tum

L aye r 1 ,S he l l L en s 1

Moa b one

9 17 ± 5 5

T ab le 3 . 5 . R ad ioca rbon a ge s a nd p rovenance o fs amp le s f r om t h e F ox ton moa -hun t ing s i te . ( P rovenance d a ta a cqu i red f r om 1 GNS s i te r e co rd f o rms ) .

c ons ide red o n ly t h ree a r chaeo log ica l d epo s i t s , o ne o fw h ich h ad s uf f e red f r om p o s t -depo s i t iona ld i s tu rbance .

o t he r m a te r ia ls i ne a r ly s t ud ie s , t h e ref o re , m ay h ave b een i n e r ro r b ecause ma r ine s he l l d a te s c ompa red w i th c ha rcoa l a ges h ad b een c o r rec ted u s ing d i f f e r ing ma r ine s h e l l s t anda rd s ,o rc a lcu la t ion m e thod s .

A l though m a r ine s he l l h a s f r equen t ly b een u sed t o d a te a r chaeo log ica l s i t e s i n N ew Z ea land , i th a s r e ce ived l i t t le d e ta i led a na ly s i s i nt h is c oun t ry ( o the rt h an H igham 's ( 1993) r e sea r ch ) . T h i s m a te r ia l i sc ons ide r ed r e l iab le f o r d a t ing a t t h e I GNS a nd Wa ika to l a bo ra to r ie s , a s i ti s i n o ve r sea s l a bo ra to r ie s , b u t a s r e sea r ch h as b een l i m i ted h e r e i nN ew Z ea land , i t ss ho r t -com ing s , c ompa t ib i l i ty , o ra dvan tage s o ve r c ha r coa l r e qu i r e f u r the rt e s t ing .

T h is s u rvey o f t h e l i t e ra tu re h a s i d en t if ied , h oweve r , t h ree u n ive r sa l ly a ccep ted r e commenda t ions w i th r e spec t t o t h e d a t ing o ft h r ee s amp le t y pe s : •

i fd a t ing c ha rcoa l , u se t w ig s o f s ho r t l ived t r ee a nd s h rub s pec ie s ;

•

i fu s ing b one , d a te t h ec o l lagen f r ac t ion ;

•

w hen d a t ing ma r ine s he l l , t e s t f o r r e cry s ta l l isa t ion a nd d on o tu se Amph ibo la c rena ta ( mud sna i l ) .

T h is n eed f o r f u r the rr e sea r ch i se spec ia l ly r e levan t w hen w e c ons ide r c ommon b e l ief s a mong s t t h e N ew Z ea land a r chaeo log ica l c ommun i ty , a bou t t h e r e l iab i l i ty o f d a t ing p a r t icu la rm a r ine s he l l s pec ie s , a nd e nv i ronmen t s w h ich m ay b ea tr i sk f o rd a t ing .

O ft h e se t h ree s amp le t y pe s , c ha r coa l h a s r e ce ived t h e mo s t a t ten t ion a nd r e sea rch . O n ly t wo d e ta i led s t ud ie s , t h o se o f A nde r son ( 199 1) a nd H igham ( 1993 ) , h ave b een m ade u s ing i d en t if ied c ha rcoa l . T he se s t ud ie s i lu s t ra ted t ha t c ha r coa l w a s ar e l iab le s amp le t y pe f o r d a t ing w hen t w ig s o f s ho r t l i ved s pec ie s w e re u sed . A l so , t h ey s howed t h a t c on tam ina t ion o fc ha rcoa l f r om a r chaeo log ica l c on tex t s w a s n eg l ig ib le , a nd t h a t t h e o n ly r e a l p rob lem a s soc ia ted w i th t h is s amp le t ype w a s o cca s iona l i n bu i l t a ge ( Ande r son 1 991 :784 -788 ; H igham 1 993 :156 ) . S uch s pec if ic i n d iv idua l a na ly s is o f as amp le t ype h a s n o t b een c a r r ied o u t o n b one " (even t h ough t h e re a r e m any m oa b one d a tes f r om moa h un t ing s i te s ) , a nd t h e o n ly s t udy w h ich l o oked a t m a r ine s he l l , p a i red w i th i d en t if ied c ha r coa l ( H igham 1 993 ) ,

A s d i scus sed a bove , A nde r son ( 199 1) o u t l ined t wo m a in c once rns r e ga rd ing t h e r a d ioca rbon d a t ing o f ma r ine s h e l l i n N ew Z ea land a r chaeo logy . F i r s t , t h a t t h e e s tua r ine b i va lve A u s t rovenu s s t u tchbury i i s u n re l iab le b ecause i t m ay i n co rpo ra te d i s so lved a nc ien t c a rbon w i th in i t s p a r t icu la r h ab i ta t . T h i s a r gumen t h a s b een s uppo r ted b y o ne e xamp le , t h e F ox ton m a r ine s he l l r a d ioca rbon d a tes . S econd , t h a t u pwe l l ing a tK a ikou ra , c an c ause m a r ine s he l l r a d ioca rbon d a te s f r om t h i s l o ca t ion t oa ppea r t oo o l d . A ga in , t h e A voca P o in t ma r ine s h e l l r a d ioca rbon a ge s a r et h e o n ly e xamp le st o h ave b een p r e sen ted a se v idence f o rt h i se f f ec t .

II D rF iona P e tchey ( 1998 )h a sr e cen t ly c omp le ted r e sea r ch o n t h e r e l iab i l i ty o fS nappe r( Pag ru sa ura tu s )a nd B a r racou ta ( T hy r s i tes a t un ) b one f o rr a d ioca rbon d a t ing N ew Z ea land a r cha eo log ica l s i te s ,a nd h a s i d en t if ied t h e se f i sh s p ec ie sa sr e l iab le f o rd a t ing .

2 6

When w e e xam ine t h e r a d ioca rbon d a t e s a nd a s soc ia ted a r chaeo log ica l m a te r ia l f r om t h e F ox ton s i te , p o s t d epo s i t iona l d i s tu rbance r a the r t han t h e h a rd w a te r e f f ec t ( s ee C hap te r 4 ) , a ppea r s t ob e a mo re l i ke ly r e a son f o r t h e a noma l ie s i nt h e s he l l a ge s f r om t h i s s i t e ( Tab le 3 . 5 ; s e e F i gu re 3 . 6 ) .

CHAPTER 3

T he S amp le T ype D i lemma

P rovenance

CRA

L une l la s p .

S qua re M20 , 1 0 -20 c m d ep th , o ccupa t iona l d epo s i t .

183 ±2 9

NZ -27 19

P ro to thaca s p .

S qua r e M20 , 1 0 -20 c m d ep th , o ccupa t iona l d epo s i t .

174 ± 3

NZ -6472

H a l io t i si r i s

4 0m , T rench A , 5 5 105 c m d ep th . B each g rave ls w i th s he l ls a nd b one s a nd s t one f l ake s ( c u l tu ra l ) i nb l a ck s i l t .

8 7 1 ±4 0

NZ -6525

C ook ia s uka ta

O ccupa t iona l d epo s i t o u t s ide w a l l a r ea r e la t ing t oe a r ly o ccupa t ion o fa r ea .

8 00 ± 3 2

L ab . N o .

Mar ine S pec ie s

NZ -27 18

S he l l

T ab le 3 . 6 . R ad ioca rbon a ge s f r om a r chaeo log ica l s i te se xcava ted a t' Avoca P o in t ' .

I f w e a s sume t h e y oung c ha rcoa l a ge NZ -685 h a s n o t s u f f e red f r om i n bu i l t a ge ( none o ft h e c ha r coa l s amp le s w e re i d en t if ied t os p ec ie s p r io r t o d a t ing ) , i ta ppea r s a noma lou s g i ven i t s a s soc ia t ion w i th t h e moa b one . When t h e ma r ine s h e l l r a d ioca rbon a ge s a r e e xam ined , t h e d a te s o f A u s t rovenu s s t u tchbu ty i f o r b o th l a ye r s o f t h e s i te a r e n o t u nu sua l , c ompa red t o s h e l l ' 4C d e te rm ina t ion s f r om o t he r m oa -hun t ing s i te ss uch a sS hag Mou th o rP l ea san tR ive r ( s ee H igham 1 993) . T he P aph ie s s ub t r iangu la tum r a d ioca rbon d a te NZ 1250 , h oweve r , a ppea r s t o b e t o o y oung g i ven i t s a s soc ia t ion w i th moa r ema ins ( a s f o und w i th i t s p a i red m odern c ha r coa l a ge ) . T he A u s t rovenus s t u tchbu ty i r a d ioca rbon a ge s NZ 125 1 a nd NZ 1347 a r e t yp ica l f o r a m oa -hun t ing s i te , b u t t h e se a r e f ound a l ong s ide E u ropean m a te r ia l . T he r ad io ca rbon a noma l ie s i d en t if ied a t t h e F ox ton s i te o c cu ra tt h e i n te rf ace o fl e n se s 3a nd 4i nL aye r 2( s ee F igu re 3 . 6 ) . T he se l e n ses h ave c ha rac te r is t ics w h ich i n d ica te m ix ing o ft h e t wo d epo s i t s ; t h e y oung P aph ie ss ub tr iangu la tum a nd c ha r coa l r a d ioca rbon a ge s f r om L en s 3o f L aye r 2f ound w i th moa r ema ins , a nd t h e o l de r A u s t rovenus s t u t chbu ty i r a d ioca rbon d a te s a l ong s ide E u ropean c u l tu ra l m a te r ia l i n L en s 4 o f t h e s ame l a ye r . I n s ho r t , t h e re a r e s eve re q ua l if ica t ion s w h ich h ave t o b e m ade r ega rd ing t h e i n te rp r e ta t ion t h a t a n e nv i ronmen ta l f a c to r h a s c au sed t h e v a r iab le r a d ioca rbon a ge s f r om t h e F ox ton s i te . I ti s mo re l i ke ly t h a t t h e e r ro r s a r e r e la ted t o p o s t -depo s i t iona l m ix ing o f c u l tu ra l d epo s i t s . F u r the r r e sea rch w ou ld b e r e qu i red t o c onf i rm t h i s .

c ome f r om O ld P i e r P o in t , a nd NZ -6472 a nd NZ -6525 f r om t h e F yf f e 's s i te . T he r ad ioca rbon d a te s ,t h e ref o re , a ppea rt od a te t wo d i f f e r en t o ccupa t iona l d epo s i t s o fv a ry ing a ge . T he o l d d a te s a r e n o t c aused b y u pwe l l ing a sA nde r son ( 199 1 :777 ) a nd C augh ley ( 1988 ) h ave s ugge s ted . H igham ( 1993 :137 138 ) u nder took a s ma l l s t udy r ega rd ing u pwe l l ing a t K a ikou ra b y d a t ing mode rn A u s t rovenu s s t u tchbury i t a ken c l o se t o t h e F yf f e 's m oa -hun t ing s i te , a nd f ound t h a t t h e s amp le h ad n o t b een a f f ec ted b y u pwe l l ing . B ecau se o n ly o ne s amp le w a s t e s ted , H igham c onc luded t h a t f u r the r r e sea r ch c oncer n ing u pwe l l ing a tt h e s i te w ou ld b e u s ef u l( 1993 :138 ) . T he F ox ton a nd A voca P o in t e xamp le s i l u s t ra te , t h e ref o re , t h a t t h e a noma lou s r a d ioca rbon a ges o n t h e s h e l lf i sh s pec ie s d a ted m ay n o t b e d ue t ot h e r e a sons o r ig ina l ly p ropo sed . I n a dd i t ion , t h ey p rov ide f u r the r e v idence o f t h e n eed f o r t e s t ing t h e r e l iab i l i ty o f m a r ine s he l l t o e s tab l ish i t s u sef u lne s sf o rr ad ioca rbon d a t ing N ew Z ea land p r eh i s to ry . AS o lu t ion t o t he S a mp le T ype D i le m ma I ti sa ppa ren t t h a t a n i n ve s t iga t ion i n to t h e r e l iab i l i ty o f m a r ine s h e l l f o r N ew Z ea land a r chaeo logy w ou ld b e v e ry u sef u l a t t h is t ime . A s c ha r coa l a nd m a r ine s he l l a r e u b iqu i tou s i nN ew Z ea land p r eh i s to r ic s i te s , i n ve s t iga t ing t h e u se o fm a r ine s he l l w ou ld g r ea t ly i n c rea se c onf idence i nt h e c ho ice o fs amp les t od a te f r om a r chaeo log ica l s i t e s . T he mo s t s a t isf ac to ry m e thod f o re va lua t ing t h e r e l iab i l i ty o f m a r ine s he l l i st o u se m a r ine s h e l l / iden t i f ied c ha r coa l p a i r s . A n a l terna t ive t o c ha r coa l w ou ld b e moa e gg s h e l l f r om a n a r chaeo log ica l c on tex t , a s H igham 's ( 1993 ; 1 994 ) r e sea r ch h a s f ound t h is ma te r ia l t o b e r e l iab le f o r d a t ing . H oweve r , moa e gg s he l l i sn o t w idesp r ead i nn o r ther n N ew Z ea land a r chaeo log ica l s i te s( H igham 1 993 :96 ; 1 994 :168 ) .

T he m a r ine s h e l l r ad ioca rbon d a tes f r om A voca P o in t a r e m o re e a s i ly e xp la ined t h an t h e F ox ton r a d ioca rbon a ge s . NZ 2 7 18 a nd NZ -2719 f r om t h e s i te a r e c a . 3 00 y ea r s o l de rt h an NZ -6472 a nd NZ -6525 ( Tab le 3 . 6 ) . H oweve r , t h e s amp le r e co rd f o rms f r om t h eI GNS l a bo ra to ry i n d ica te t h a tn o to n ly w e re s amp le s NZ -2178 a nd NZ -2179 c o l lec ted t e n y ea r s e a r l ie r t h an NZ -6472 a nd NZ -6525 , b u t b o th s e t s o f r a d ioca rbon d a tes c ame f r om d i f f e r ing l o ca t ions . I na dd i t ion , t h e p rovenance o ft h e s amp le s d a ted f r om e ach o ccupa t iona l d epo s i t a r e a tm a rked ly d i f f e r ing d ep th s , a nd b o th c o l lec t ion s i t e s a r e k nown b y d i f f e r ing n ame s , NZ -27 18 a nd NZ -27 19

T h i s s t udy w i l l i n ve s t iga te t h e u se o f m a r ine s h e l l i n r a d ioca rbon d a t ing N ew Z ea land p r eh is to ry , b y c ompa r ing c ha rcoa l r a d ioca rbon a ge s w i th ma r ine s he l l d a te s f r om a r chaeo log ica l s i te s s amp led f r om v a r ious l o ca t ion s a r ound N ew Z ea land .

2 7

CHAPTER 3

T he S amp le T ype D i lemma

H oweve r , b ef o r e ac ompa r ison c an b e m ade b e tween t h e se s amp le t y pe s , i ti s v i ta l t o r e cogn i se f a c to r s w h ich c an i nf luence t h e a c cu racy o f r a d ioca rbon d a te s f r om t h e se m a te r ia ls . F o r e xamp le , h ow d oe s h a rd w a te r a f f ec t t h e r ad ioca rbon d a t ing o f m a r ine s h e l ls , a nd w ha t f a c to r s s t i l l a f f ec t c ha r coa l d a te s e ven w hen t h e c ha rcoa l h a s b een i d en t if ied t ot w ig s o fs hor t l ived s pec ie s p r io r t od a t ing? I n a dd i t ion , t h e w ay i nw h ich ma r ine s he l l CRAs a r e c a l ib ra ted mus t b e s c ru t in i sed t o d e term ine w he the r t h i s p rov ide s a ny s i gn if ican ts ou r ce o fe r ro r .

2 8

CHAPTER 4

RAD IOCARBON DAT ING CHARCOAL AND MAR INE SHELL : CONS IDERAT IONS FOR USE

c ha r coa l m ay b e i d en t if ied t ot w ig s o fw ha t i sb e l ieved t ob e s ho r t l ived s pec ie s , s ome o f t h e se s pec ie s m ay i n f a c t l i ve c on s ide rab ly l o nge r t h an a s sumed . F o r e xamp le , h e n o t ed t h a t s ome b o tan is t s b e l ieve t h e P seudopanax s pec ie s a nd k anuka ( Kunzea e r ico id e s ) m ay l i ve u p t o 2 00 -300 y ea r s , a nd t h a t m anuka ( Lep to spe rmum s copar ium ) m ay l i ve u p t o 1 00 y ea r s . A nde r son a l so f ound t h a tN ew Z ea land s h rub s c an p robab ly l i ve f o r 5 0 100 y ea r s ( Ande r son 1 99 1 :780 ) . H e s aw t h a t t h e p rob lem o f i n bu i l t a ge w a s e nhanced f o r s amp le s b e ing u sed t o d a te s i te s o f b r ief o ccupa t ion , a nd t h a t " Cha r coa l s amp le s o f' s hor t l i f e span ' s pec ie s , e ven w he r et h e m a te r ia l a l so a ppea r s t o b e o f y oung w ood , s t i l l i n d ica te i n bu i l t a ge s o f 5 0 150 y ea r s , o r g r ea te r . . ." ( Ande r son 1 99 1 :78 1) .

I NTRODUCT ION T o t e s t p rope r ly t h e r e l iab i l i ty o f a s amp le t ype f o r r a d ioca rbon d a t ing a n a r chaeo log ica l s i te , p ar t icu la r c on s ide ra t ion s mus t b e t a ken i n to a ccoun t . T h is c hap te r e xp la ins w ha t f a c to r s c an a f f ec t t h e t r ue r a d ioca rbon a ge s o f c ha rcoa l a nd m a r ine s he l l s amp le s u sed t od a te N ew Z ea land a r chaeo log ica ls i te s . THE PROBLE M

OFI NBU ILT

AGE

B ecau se r a d ioca rbon d a t ing a ims t om ea su re t h e t ime l a p sed s i nce a n o rgan i sm 's d ea th , i n bu i l t a ge o fc ha r coa l c an m ake d a t ing o fa r chaeo log ica l c on tex t s p rob lema t ic . I na n a t temp t t o a lev ia te t h i s p rob lem , a r chaeo log is t s h ave , s i nce 1 976 , i d en t if ied t h e c ha rcoa l r e cove red f r om a r chaeo log ica l c on tex t s t o s ho r t l ived t r ee a nd s h rub s pec ie s . S e lec t ing t w ig s a dd i t iona l ly r ef ined t h is s amp le w he re i tw a s a s sumed t h a t t h e se r e p re sen t o n ly a f ew y ea r s o f g row th , a nd s u ch d e l ica te f o l iage wou ld n o t s urv ive l o ng a f te r d ea th ( s ee C hap te r3 ) .

I n d a t ing t h e c o lon isa t ion o f N ew Z ea land u s ing c ha r coa l , McFadgen e ta l . ( 1994 :224 ) s epa ra ted s amp le s r a d ioca rbon d a ted u s ing s ho r t l ived s pec ie s ( < 1 00 y ea r s ) f r om t h o se o n l o ng l ived s pec ie s ( > 100 y ea r s ) , b a sed o n t h e c r i te r ia s hown i n t a b le 4 . 1 . T hey o b served t h a t w hen s epa ra t ing c ha r coa l a ge s u s ing t h is c r i te r ia , t h e re w e r e f ewe r d a te s o n s ho r t l ived s pec ie s w i th a ge s >7 00 y ea r s c a l B P w hen c ompa red t o d a te so n l o ng l ived s pec ie s ( McFadgen e ta l . 1 994 :224 -225 ) .

A nde r son ( 1 99 1) a nd McFadgen e ta l . ( 1994 ) h ave t a ck led t h e p rob lem o f i n bu i l t a ge i n u s ing c ha rcoa l t o d a te N ew Z ea land p r eh i s to ry . A nde r son ( 199 1) f ound t h a t e ven t h ough S ho r t ( < 1 00 y r )

Med ium ( 1 00300 y r )

L ong ( >3 00 y r )

A r i s to te l ia s e r ra ta B rachyg lo t t i ss p . C arm ichae l ia s p . C arpod e tu ss e r ra tust C as s in ia s p . C opro sma s p . C or iar ia s p . C orok ia m acr ocarpa G en io s toma r upe s tr e H ebe s p . H edycarya a rboreat L ep tospermum s copar iumt L eucopogon f u sc icu la tus L ophomy r tu so bco rda tat Macrop ipe re xce l sus Me l icy tu sr am tf lo rust Me l icy tus s p .$ My rs ine a u s t ra l i s Myrs ine s p . O lear ia r an i* P seudopanax a rboreu st P seudopanax c ras s if o l iust P seudow in te ra s p . P t er id ium e scu len tum S chef f lera d ig i ta ta T ree f e rn

A ckama r o s i f o l iat A lec t ryon e x ce l su s B e i l schm ied ia s p .$ C o rd y l ine a us t ra l i s C o rynoca rpus l a ev iga tu s D isca r ia t o uma tou Dy soxy lum s pec t ib i l e Hohe r ia Kn igh t ia e x ce l sa Kunzea e r ico id es Myr s ine d i var ica tat Myopo rum l a e tum Ne s t ig i ss p . O lear ia s p . P seudopanax P ara tr op i sm icrophy l la P i t to sporum e ugeno id e s P i t to spo rum t e nu if o l iumt P lag ian thu ss p . S opho ra m ic rophy l la S opho ra s p . W e inmann ia s p .

Aga th i sa u s t ra l i s Dacryd ium c upr es s inum Ha locarpus k i rk i i L agaro s t robus c o lenso it L aure l ia n ovae ze land iat L ibo ced ru sb idw i l l i it Me tro s id ero ss p . No thof agu s P hy l loc ladu ss p .t P odocarpu st o tara P rumnop i ty ss p ica tus V i tex l u censt

' Da ta p rov ided b yD r .P h i l ip S imp son , B o tan is t ,S c ienc ea nd R esea rch D iv is ion ,D epa r tmen to fC onse rva t ion . t L if es p an c an b em uch s ho r te rt h an d es igna ted y ea r s . t L if es p an c an b el o ng e r t h an d e s igna ted y ea rs .

T ab le 4 . 1 . McFadgen e ta l ' s . ( 1 994 :224 ) t a b le o fl i f e e xpec tancy o fp l an t s pec ie s u sed f o r r a d ioca rbon d a t ing i n N ew Z ea land .

2 9

R ad ioca rbon D a t ing C ha rcoa l a nd Ma r ine S he l l

CHAPTER 4

L if e E xpec tancy (McFadgen e ta l . 1 994 :224 ; S imp son p er s . c omm . )

T ree a nd S hrub S pec ie s

L a t in N ame

C ommon N ame

A ga th i sa u s t ra l i s

K aur i

1

A l ec t ryon e xce l su s

T i tok i

m

A v i cenn ia m a r ina v ar . r e s in if e ra

Manawa /Mang rove

s *

B e i l schm ied ia t a ra i r i

T a ra i r i

m *

C a rpod e tu ss e r ra tu s

P u tapu tawe ta

s * s

C op ro sma s p . D ac tyd ium c upre s s inum

R imu

I *m . m

D odonaea v i sco sa

A keake

D y soxy lum s pec tab i le

K ohekohe

H ebe s p .

K o rom iko ta ranga

s

H ed yca tya a rbo rea

P o roka iwh i r ia / P idgeonwood

s *

K un zea e r ico id e s

K anuka

m

L ep to spe rmum s copa r ium

Manuka

s *

L i t sea c a l ica r i s

Mangeao

m

L ophomy r tu sb u l la ta

R ama rama

s

L ophomy r tu so bcorda ta Mac rop iper e xce l sum

K awakawa /Peppe rt r ee

s * _ s

M e l icy tu sr am i f loru s

Mahoe

s *

Me t ro s id ero se xce l sa

P ohu tukawa

1

M e t ro s id ero sr obu s ta

V ine R a ta

I

M y r s ine a u s t ra l i s

Mapau

s * m *m

O lea r ia s p . P i t to sporum s p . P lag ian thu sr eg iu s

Mana tu /R ibbonwood

m

P od oca rpu st o ta ra

T o ta ra

1

P rumnop i ty st a x if o l ia

Ma ta i

1

P seudopanax a rboreu s

P uahou /F ive f inge r

P seudopanax c o len so i

O r ihou

s * *m

P seudopanax c ra s s if o l iu s

H o roeka /Lancewood

s * *m

H o rop i to

*m

P seudopanax s p . P seudow in te ra c o lora ta P seudow in te ra s p .

S

P te r id ium e s cu len tum

B racken f e rn

s

S chef f lera d ig i ta ta

P a te te

V i tex l u cen s

P ur i r i

s * 1

W e inmann ia r acemo sa

K amah i

m

T ab le 4 . 2 . T r ee a nd s h r ub s pec ie s c ommon ly u sed f o r r ad ioca rbon d a t ing N ew Z ea land p reh i s to ry a s s e en i n Wa ika to a nd I GNS l a bo ra to r ie s s amp le r e co rd f o rms . L if e e xpec tancy a r e b a sed o n McFadgen e ta l . ( 1994 :224 ) d a ta a nd i n f o rma t ion p rov ided b y D r . P .S imp son . s = s hor t ( < 100 y ea r s ) ; m=med ium ( 100 -300 y ea r s ) ; Hong > 300 y ea r s ) . *t o l e f t o fl i f e e xpec tancy i n d ica te s p l an t f r equen t ly l i ve s s ho r te r t h an t h is t ime , *t o t h e r i gh t m ean st h ep l an to cca s iona l ly l i ves l o nge rt h an t h i st ime .

T ab le 4 . 2 p r e sen t s t r ee a nd s h rub s pec ie s w h ich h ave b een c ommon ly u sed f o r r a d ioca rbon d a t ing i n N ew Z ea land a r chaeo logy s i nce 1 976 , a ss e en i ns amp le r e co rd f o rms f r om Wa ika to a nd I GNS r a d ioca rbon d a t ing l a bo ra to r ie s . T he l i f e

e xpec tancy o ft h e se t r ee s b a sed o n McFadgen e ta l .' s ( 1994 : 2 24 ) e s t ima t e s c an b e s e en i n c o lumn 3 . T he m a jo r i ty o f s pec ie s a r e i nt h e s hor t t o m ed ium a ge r a nge , w i th a f ew c om ing f r om l o ng l ived s pec ies . H oweve r , t h e se f l o ra l

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l i f espan s d o n o t t a ke i n to a ccoun t t h a t t h e s amp le s d a ted w e re f r om t w ig s , a nd s ome t ime s f r om s e ed s , s o a l though t a b le s 4 . 1 a nd 4 . 2 g ive a n i n d ica t ion o f t h e m ax imum l i f e s pan o ft h e f l o ra b e ing d a ted , t h e a c tua l a ge o ft h e w ood i s r e la ted t o t h e n umbe r o f y ea r s o f g row th t h e s amp le r ep re sen t s . S o w ha t d o A nde r son ( 1 99 1) a nd McFadgen e t a l .' s ( 1994 ) s t ud ies ( a nd T ab le 4 . 2 ) , t e l l u s a bou t t h e i n bu i l t a ge o f c ha r coa l u sed t o d a te N ew Z ea land a r chaeo log ica l s i tes? T hough b o th a g ree t h a t t w ig s o f s ho r t l ived s pec ie s s hou ld b e u s ed , t wo a r ea s o f d eba te a r i se : 1 ) s ome t r ad i t iona l ly a ccep ted s hor t l ived t r ee a nd s hrub s pec ie s may i n f a c t h av e b een m i s iden t if ied , a nd l i ve f o r y ea r s w e l l i n e xce s s o fw ha t i sb e l ieved , a nd 2 ) i ft w ig s o n ly r e p re sen t a f ew y ea r so fg row th , t h en t w ig s f r om l o ng l ived s pec ie s may s t i l l b e a c cep tab le f o rd a t ing . McFadgen e ta l .' s( 1994 ) s hor t l i ved a nd l o ng l ived s pec ie s r ad ioca rbon a ge c ompa r ison d oes n o t i n d ica te w he the r s amp le s o f t w ig s o n ly w e re a na ly sed . I fw ec ons ide rA nde r son 's ( 1 994 ) o b se rva t ions t h a t s ome s ho r t l ived s pec ie s ( s uch a st h e P seudopanax s p . ) may l i ve f o r2 00 -300 y ea r s ,t h en s ome o ft h er a d ioca rbon s amp le s i n McFadg en e ta l .' s ( 1994 ) ' s ho r t l ived ' c a tego ry may i n f a c t h ave h i gh i n bu i l t a ge , b ecau se e i the r t h e m a te r ia l w a s n o t d e r ived f r om t w ig s , o rt h e t r ee s p ec ie s m ay n o t a c tua l ly b e s ho r t l ived . A l terna t ive ly , s ome o f McFadgen e t a l .' s ( 1994 ) l o ng l ived ma te r ia l may c ome f r om t w ig ma te r ia l w h ich r e p r e sen to n ly af ew s e a sons g row th . T he p rob lem o fi nbu i l t a ge , t h en , m ay n o t b e f u l ly r e so lved b y s e lec t ing t w ig s f r om s hor t l ived s pec ie s b ecause , a s A nde r son ( 1 99 1 :780 ) n o ted , i ti sd i ff icu l t t o o b ta in d a ta o n l o ngev i ty o fN ew Z ea land t r ee s a nd s h rub s . I ti s , h oweve r , t h e mo s t e f f ec t ive s o lu t ion a tp re sen t t or e so lve t h e i n bu i l t a ge p rob lem .

v a r ie ty o ft r ee s pec ie s i nt h eg round , a nd t h en o nce ay ea rt h e s t ake s a r e k nocked o n t wo a d jacen t s i de s u s ing a w ooden m a l le t ( C l if ton 1 990 :4 ) . I ft h e s t ake s d on o t f a i l t h en t h ey a r e d ug u p a nd a r a t ing o f d ecay i sg iven . H oweve r , C l if ton ( 1990 :5 ) o b se rved t h a t t h e se i n d ica to r s a r e " c ompa ra t ive a nd n o t a b so lu te " b ecause o ft h e w ide r a nge o fr e su l t s . A l so , t h a t t h e r a t ing s c ome f r om t e s t s c a r r ied o u t i n s even d i f f e r en t r e g ions a r ound N ew Z ea land a nd a r e t h e ref o re i nf luenced b y av a r ie ty o f c l ima te s , t opog raph ie s a nd s o i l t ype s ( C l if ton 1 990 :5 ) . F ac to r ss u ch a st h i s c an d rama t ica l ly a f f ec tt h e d u rab i l i ty a nd d ecay r a te s o ft imbe r s . F o r e xamp le , S imp son ( pe r s . c omm . ) a nd A nde r son ( 199 1 :780 ) b o th n o te t h a t i nd ry e nv i ronmen t s s uch a si nC en t ra l O tago , t r ee sm ay t a ke h und red s o fy ea r st o d ecay . A l te rna t ive ly , B a rbe r ( p e r s . c omm ." ) o b se rve s t h a t b ecause o f t h e i n f e r t i le n a tu r e o f t h e N e lson /Ma r lbo rough a r ea , b eech w i l l n o tg row a sl a rge a si no t he r l o ca t ion so ft h e S ou th I s land , n o r f o r l o ng p e r iod s o f t ime , a nd t h e e nv i ronmen t b r ing s a bou t r a p id d ecay a f t e r d ea th . F o r e s t w ood u s ed b y p eop le i np reh i s to ry mo s tp robab ly c ame f r om t h es u rf ace o ft h eg round w he r et h e t r ee f e l l . C l if ton ( 1990 :4 ) n o ted t h a t " a s pec ie s r anked mode ra te ly d urab le i n t h e g round w ou ld b e c l a s s if ied a s d u rab le a bove t h e g round " . H ence d u rab i l i ty a nd d ecay t e s t s o n N ew Z ea land t imbe r s a t p r e sen t w i l l o n ly g i ve a g ene ra l i n d ica t ion o f t h e t i me a f a l len t r ee w i l l l i e o n t h e f o re s t f l oo r r e la t ive ly i n tac t a nd b e a va i lab le a sf i rewood . B ecau se o ft h is , t h e i nf luence o fd ecay r a te s o n i n bu i l t a ge o fc ha r coa l s amp le s c an n o t c u r ren t ly b e d e te r m ined . L IFE WAYS AND HAB ITATS O F SHELLF ISH

O ne a s pec t o f i n bu i l t a ge n o t o f t en c l o se ly e xam ined , a nd w h ich m ay h ave a g r ea te r i nf luence o n d a te s o n c ha rcoa l s amp le st h an b e l ieved , i st h e s t o rage a ge o rd u rab i l i ty o ft r ee a nd s h rub f o l iage ( s ee A nde r son 1 99 1 :780 -78 1) . When s e lec t ing s u i tab le c ha rcoa l f o r d a t ing , t h e s e lec t ion o ft w ig s o f s ho r t l ived s pec ie s i sb e l ieved t o a c coun t f o r b o th t h e g row th a nd s t o rage a ge ( a s d i scu s sed a bove ) . I ti so f t en p resumed t h a t b y s e lec t ing a t w ig , s t o rage a ge i s i mmed ia t e ly a ccoun ted f o r , a nd t h e o n ly r ema in ing a r ea o f c once r n i st h e g row th a ge . T h i s i st r ue w hen a t temp t ing t o e xc lude a n c ien t d r if twood f r om a s amp le w he r e t w ig s a r e l e s s l i ke ly t o s u rv ive i n ac oa s ta l e nv i ronmen t b ecause o f t h e i r f r ag i l i ty . H oweve r , t r ee s w h ich h ave d i ed a nd l i e i n f o re s t so ro nf o res t ma rg in s , m ay v a ry i nb o th t h e i rd u rab i l i ty a nd t ime t a ken t o d ecay i nt h e e nv i ronmen t . I ti sg ene ra l ly b e l ieved t h a t mo s t s ho r t a nd m ed ium l ived t r ee s a nd s hrub s d ecay w i th in 1 00 y ea r s i n t h e N ew Z ea land e nv i ronmen t ( S imp son p e r s . c om . I 2) . T he l o ng l ived s pec ie s s uch a s t o ta ra , p u r i r i , a nd k au r i , d ecay v e ry s l ow ly , b u t b eech , a l so a l o ng l ived s p ec ies , d ecay s q u ick ly . D ecay r a te i s a l so t h e ref o r es p ec ie s s pec if ic . V e ry l i t t le i n f o rma t ion i sa va i lab le o n t h e d e cay r a te o fN ew Z ea land t r ee s i n e i the r f o res t o r c oa s ta le nv i ronmen t s . C l if ton ( 1 990 :4 -5 ) u nder took a t e s t c ommon ly u sed b y c omme r c ia l t imbe r i n du s t r ie s t o p rov ide " na tu ra l d u rab i l i ty r a t ing s " o f N ew Z ea land i n d igenou s t imbe r s . T he t e s t i n vo lve s p l a c ing 5 0 x5 0 mm s t ake s f r om t h e h ea r twood o fa

T he t wo c l a sse s o f mo l lusc c ommon ly u sed t o r ad ioca rbon d a te a r chaeo log ica l s i tes a r e b i va lve s a nd g a s t ropod s . T o u nde r s tand t h e p a t ter n o f 1 4C u p take i n s he l lf i sh , i ti s n ece s sa ry t o e xam ine t h e w ay i n w h ich t h e s h e l l i s c ons t ruc ted a nd t h e h ab i ta t s i nw h ich t h e d i f f e r ing s p ec ie s d we l l . F rom t h i s i n f o rma t ion t h e s ou r ce s o f ' 4C i n t h e c a lc ium c a rbona te o f t h e s h e l l m ay b e i d en t if ied , a nd t h e i nf luence o f s he l lf i sh h ab i ta t a nd e nv i ronmen t o n t h e r a d ioca rbon d a te e xam ined . Cons truc t ion o ft he S he l l a nd Carbon S ources T he s he l l o f b iva lve s a nd g a s t ropod s h ave e s sen t ia l ly t h e s ame s t ruc tu re a nd a r e f o rmed i n as im i la rm anne r . T he s h e l l c omp r i se s ap e r io s t racum c ove r u nde r w h ich l i e s b e tween 2 t o 4c a lca reous l a ye r s ( F igu re 4 . 1) . T he m a in f u nc t ion o ft h e p e r io s t racum i st o a i d s he l l s e c re t ion a nd , a dd i t iona l ly , t o p ro tec t t h e c a lc ium c a rbona te b e low f r om d i s so lu t ion ( Ba rne s 1 987 :403) . T he c a lca r eous s t ruc tu r e m ay b e t o ta l ly a r agon i t ic , ( eg . c ock le s , p ip i , t u a tua o r w he lks ) , o r c a lc i t ic ( e g . o y s te r s ) . T he c a lca reou s l a ye r s a r e d epo s i ted e i the r a s p r ism s , m inu te l a th s , o r t a b le t s t ruc tu re s i n t h e f o rm o f s hee t s , l e n ses o r mo re c omp lex f o rms ( Bar ne s 1 987 :404 ) . T he b a s ic b u i ld ing b lock s o f t h e s he l l a r e t h e p r i sm a nd t a b le t s t ruc tu res w h ich a r e l a id d own w i th in a n o r gan ic m a t r ix . T he se s t ruc tu res a l ong w i th t h e p e r io s t racum , c an a ccoun t f o ru p t o7 2% o ft h e s h e l l 's d ry w e igh t . T he m an t le , w h ich o ve rhang s t h e b ody o ft h e mo l lu sc b enea th t h e s h e l l , f o rms a l a rge s hee t o f t i s sue l o ca ted u nde r t h e v a lve s a nd c ons i s t s o f t h ree f o ld s ; a n i n ne r , m idd le a nd o u te r ( F igu r e 1 3 D r . I .B a rbe r , A rcha eo log is t , N ew Z ea land H i s to r ic P l a ce sT ru s t , We l l ing ton .

1 2 D r . P .S imp son , B o tan i s t , S c ience a nd R e sea r ch D iv i s ion , D epa r tmen to f C onser va t ion , We l l ing ton .

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s he l l . S he l l s e c r e t ion b eg in s i n t h e s ma l l g ap b e tween t h e m an t le a nd t h e s h e l l . T h i s g ap c on ta in s t h e e x t rap i l l ia l f l u id f r om w h ich i sd e r ived b o th t h e c a lca reous e l emen t s a nd t h e s u r round ing o rgan ic f r amewo rk c on s i s t ing o f t h e p ro te in c onch io l in ( F igu r e4 . 2 a nd 4 . 3) ( Bar ne s 1 987 :350 ,4 04 -405) .

4 . 1) . T he i n ne r f o ld c on ta in s t h e r a d ia l a nd c i rcu la r m usc le s o ft h e s he l lf i sh a nd a r e u sed f o r m ovemen t . T he m idd le f o ld h a s as e nsory f u nc t ion . T he o u te r f o ld i sa c t ive i n s he l l s e c re t ion w i th i t s i n ne r s u rf ace l a y ing d own t h e p e r io s t racum , a nd t h en t h e o u te r s u rf ace s e c re t ing t h e f i r s t c a lca reous l a ye r ( Ba rne s 1 987 :404 ) . T he w ho le m an t le s u rf ace t h en s e c re te st h e r e s t o ft h e c a lca reou s p o r t ion o ft h e

F igu re 4 . 1 . T ransve r se s e c t ion t h rough ab iva lve s how ing c a lca reou s l a ye r s , m an t le f o ld s a nd t h e p e r io s t racum , w h ich a i d s i ns he l l s e c re t ion ( f rom B ar ne s 1 987 :403 ) .

F igu re 4 . 2 . S he l l s e c r e t ion i n mo l lu sc s a s s e en i n ap u lmona te s na i l . B ar ne s ( 1987 :35 1) e xp la ins : " Pe r io s t racum i ss e c re ted i n i t ia l ly a tt h e b o t tom o ft h e p e r io s t raca l g roove a nd i st h ickened a s i tp a s se s o ve r t h e m an t le e dge . S ec re t ion o ft h ec a lca reou sp o r t ion o ft h es he l l b eg in st ot h e i n ne rs i de o ft h em an t le e dge g land ." .

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R ad ioca rbon D a t ing C ha rcoa l a nd Ma r ine S he l l

F igu re 4 . 3 . P roce s s b y w h ich s he l l i sf o rmed b y b i va lve s a nd g a s t ropod s . B a rne s ( 1987 :405 ) e xp la in s : " P ro te in a nd m ucopo ly saccha r ide s a r e i n vo lved i nt h e p roduc t ion o ft h e o rgan ic f r amewo rk o ft h e s h e l l . C a lc ium l o s s o ccu r sd u r ing p e r iod so fd i s so lu t ion" . s pec ie s h ab i ta t i si mpo r tan t ( s ee T anaka e ta l . 1 986 ; L i t t le 1 993 ; H igham 1 993 ; D ye 1 994 ) .

T he e l emen ta ry c a rbon w h ich f o rms t h e C aCO 3 o ft h e s h e l l c omes f r om t h r ee s ou r ce s : D IC ( d i s so lved i n o rgan ic c a rbon ) i nt h e f o rm o f HCO 3- f r om t h e s e awa te r , c on t r ibu t ing t h e l a rges t p ropor t ion o fc a rbon ; m e tabo l ic c a rbon i nt h e f o rm o f CO , f r om t e r r e s t r ia l a nd m a r ine o rgan ic f ood s ou rce s ; a nd p o s s ib ly am ino ra moun t f r om a tmo sphe r ic CO , f o re s tua r ine s pec ie s ( Tanaka e ta l . 1 986 :520 ; L i t t le 1 993 :468 ; H igham 1 993 :121123 ) . B iva lve s , s uch a s A u s t rovenu s s t u tchbu ty i ( c ock le ) , P aph ie s a u s t ra l i s ( p ip i ) a nd P aph ie s s ub t r iangu la tum ( t ua tua ) , d raw s e awa te r a nd s u spended o rgan ic m a t te r t h rough a n i n ha l ing s i phon o ve r p a i red c t en id ia ( g i l l s ) . T he c t en id ia a c t a s g a s e xchange m ed ia a s w e l l a s f i l te r s s epa ra t ing d eb r is f r om f ood ( Ba rne s e t a l . 1 993 :133 134 ) . F rom h e re c a rbon i st a ken b o th d i rec t ly i n to t h e man t le f r om t h e s u r round ing w a te r ( a s b i ca rbona te i o ns ) , a s w e l l a s f r om t h e d i ge s t ion o f o rgan ic m a t te r ( me tabo l ic c a rbon i n t h e f o rm o f CO , ) ( F igu re s 4 . 2 a nd 4 . 3) . T he G a s t ropod s L une l la s ma ragda ( c a t seye ) , C om ine l la a d spe r sa , a nd C om ine l la v i rga ta ( t he l a te r w he lk s ) , a l so o b ta in t h e i r c a rbon f r om t h e i mmed ia te s e awa te r , b u t t h e i r m e tabo l ic c a rbon c ome s f r om t h e u se o f r a du la i nL une l la s ma ragda , o re x ten s ib le p robo sc i s f e ed ing f o rC om ine l la s p . , r a the r t h an f r om f i l te r ing . L une l la s ma ragda g raze u pon o rgan ic d epo s i t s a nd c o ra l l ine s ( a lgae ) , a nd b o th C om ine l la s p . a r e c a rn ivo rous , ( t hough C om ine l la a d sper sa i s a s c avenge r r a the r t h an a p reda to r ) ( Mo r ton a nd M i l le r 1 968 :391 ,3 98 ) .

HA B ITATS OFSH ELLF ISH US ED FOR RAD IOCARBON DA T ING NEW ZE ALAND ARCHAEOLOG ICAL SI TES B iva lves T he m o s t c ommon s he l lf i sh f o und i n Mao r i p r eh i s to r ic m idden s a r e A u s t rovenu s s t u tchbu ry i , P aph ie s a u s t ra l i s a nd P aph ie s s ub t r iangu la tum . A u s t rovenu s s t u tchbu ty i l i ve s i na v e ry s im i la r h ab i ta t t o P aph ie s a u s t ra l i s . B o th s pec ie s a r e f ound o n b road l e ve l b each f l a t s e i the r i ns he l te red b ay s o ra t t h e m ou th s o f e s tua r ie s , w h ich a r e p ro tec ted f r om h a r sh w ave e nv i ronmen t s ( Mo r ton a nd M i l le r 1 968 :443 ) . P ip i p r ef e r ac oa r se s a nd t o i n hab i t , t h ough w i l l e x tend u p o n to t h e e dge s o fs he l te red mud f la t s o fe nc lo sed b ea che s . Mor ton a nd M i l le r( 1968 :486 ) n o te t h a t p i p i " f lou r ish" i nt h is h ab i ta t w hen f r e sh w a te r s e ep s u p t h rough t h e b ea ch . C ock le s c an a l so b e f o und i nt h is h ab i ta t a sw e l l a so n t h e e nc lo sed b each mud f la t s . B o th t h e p ro tec ted a nd e nc lo sed b each a r ea s e xpe r ience g en t le w ave movemen t o n ly , w h ich a i d s i nt h e s t i r r ing u p o fs i l t f o r f i l te r f e ed ing . T he se s he l lf i sh a r e a l so t yp ica l ly i mmob i le a nd a r e f ound i nc l us te r s , t hough c ock le s d o o cca s iona l ly move a l ong t h e b each t o mo re p r ef e rab le f e ed ing a r ea s . P ip i a nd c ock le s c an b e f ound b ur rowed j u s t b e low t h es u rf ace u pt o 4c m d eep . P aph ie s s ub t r iangu la tum a r e t y p ica l o f t h e o pen b each h ab i ta tw he re c l ean s and a nd d i rec t w ave a c t ion a r e c on s tan t i na n u nshe l te red s u r round ( Mo r ton a nd M i l le r 1 968 :443 ) . T he se s h e l lf i sh a r e a lway s mov ing w i th t h e s h if t ing s a nd s a nd c an b e f ound , a sw i th p i p i , o n ly ac oup le o fc en t ime t re s b e low t h e s u rf ace . V enerup i s l a rg i l l ie r t i , t h e o b long c ock le ,

Ma r ine s h e l l r a d ioca rbon a ge s a r e r e la ted t o t h e i n take o f D IC f r om t h e m a r ine e nv i ronmen t , b u t t h is m ay b e a f f ec ted b y t h e i n co rpo ra t ion o f m e tabo l ic c a rbon . T h is a nd o t he r f a c to r s a r e d ependen t o n t h e h ab i ta t a nd e nv i ronmen t o ft h e mo l lu sc s p ec ie s b e ing d a ted , a nd t h e ref o re a k now ledge o f

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CHAPTER 4

i sa l so s ome t ime s f ound i nm iddens . T h is s p ec ie s i n hab i t s s i l ty s a nd o fe nc lo sed b eache s o f ten i na s soc ia t ion w i th t h e s of t s ho re p l an t s o ft h e Z o s te ra s p . , w h ich l i e a tt h e f oo t o f m ang rove s wamp s ( Mor ton a nd M i l le r 1 968 :543 ) . T h i s s pec ie s o f b i va lve b ur row s d own 5 t o 6c m i n to t h e s and f r om w he re i ti n ha les f ood a nd w a te r w i th i t s l o ng s i phons w h ich e x tend t ot h es urf ace .

move q u ick ly b e tween t h e t i de s ( Mo r ton a nd M i l le r 1 968 :85 , 3 9 1) . FACTORS THAT I N FLUENCE THE RAD IOCARBON DAT ING OFSH ELLF ISH The ' Hard Wa ter E f f ec t ' a nd ` Upwe l l ing ' E ach o ft h e se f a c to r s a r e c ommon e xp lana t ions f o rv a r ia t ion s i n ma r ine s he l l a ge s . T hey c ause m a r ine s he l l r a d ioca rbon d a te s t oa ppea r t o o o l d . T h is i sc au sed b y a n i n c r ea se i nt h e a moun t o f ' 4C -dep le ted d i s so lved i n o rgan ic c a rbon ( D IC ) ( a lso k nown a sd ead o ro l d c a rbon ) , w i th in t h e h ? /d ro log ica l e nv ironmen t i n w h ich t h e s he l lf i sh l i ve . T h is C -dep le ted c a rbon d i lu te s t h e n a tu ra l l e ve ls o f ' 4C i n t h e w a te r , d ec rea s ing ' 4C a c t iv i ty , a nd t h e ref o re i n c rea s ing t h e a ge o f t h e s he l lf ish .

O ft h e r o cky s ho re b iva lve s p ec ie s , My t i lu s e du l i s a o teanu s ( b lue mu s se l ) , P erna c ana l icu lu s ( g reen mu s se l ) , a nd C ra s so s t rea g lomera ta ( t he r o ck o y s te r ) w e re c ommon ly e xp lo i ted s he l lf i sh i n p r eh is to ry . T he b l ue mu s se l w a s h a rve s ted i nt h e s ou the rn a r ea s , w he r ea s t h e g r een m u s se l w a s t a ken i nt h e n or thern r e g ion . B o th s pec ie s a r e c ommon i nt h e i r p ar t icu la r p rov ince s , b u t l e s s c ommon i np ropo r t ion t o e ach o t he r o n t h e i r o ppo s ing i s land s . P e rna c ana l icu lu s u sua l ly i n hab i t s o pen c oa s t s b u t i sa l so f ound i ns he l te red c oa s ta l l o ca t ions ( Mor ton a nd M i l le r 1 968 :62 , 3 04 , 3 42 3 43 ) . T h i s mu s se l a t tache s i t s e lf t or o ck s u s ing t o ugh b y s sus t h r ead s ,a nd f o rms ma s se so fi n d iv idua l sw h ich p rov ide m o re r e s i s tance t o p ound ing w ave s o f t h e o pen c oa s t . My t i lu s e du l i s a o teanu s i n hab i t s am o r e s he l te red e nv i ronmen t , o n ly a ppea r ing o cca s iona l ly o n o pen c oa s t sa nd t h en o n ly i ns ma l l c l u s te r s ( Mo r ton a nd M i l le r 1 968 :304 , 3 42 -343 ) . T he i r p r ef e r r ed h ab i ta t a r e i n le t s w i th a s t rong p a s s ing w a te r c u r ren t w he re , a s w i th P e rna c ana l icu lu s , t h ey a r e a t ta ched t o t h e r o ck s t ra ta w i th s t rong b y s su l t h read s , o r i n p oo ls b eh ind t h e s p la sh z one o f t h e o pen c oa s t . When i n a s soc ia t ion w i th My t i lu s e du l i s a o teanu s i n s he l te red e nv i ronmen t s , P erna c ana l i cu lu s w i l l a lway s b e s e en l i v ing o nt h er o ck f a ce s i mmed ia te ly b e low .

T he Ha rd Wa te rE f f ec t T he ' h a rd w a te r e f ec t ' c an o r ig ina te f r om t wo s ou rce s . Wa te r d ra inage f r om g eo log ica l l a nd scape s o f l i me s tone o r o t he r h igh ly c a lca reou s s t ra ta , c an i n t roduce ' 4C -dep le ted c a rbon i n to ama r ine r e se rvo i r , w he re i ti st h en i n co rpo ra ted i n to t h e s he l l s o f m a r ine , e s tua r ine o r l a cus t r ine m o l lusc s . T h is e f f ec t i sa l so c au sed w hen s he l lf i sh l i ve u pon c a lca reous s t ra ta w h ich b ecome s as ou r ce o f ' 4C -dep le ted c a rbon w i th in t h e s ur round ing w a te r s . T he h a rd w a t e r e f f ec t i su sua l ly a s soc ia ted w i th e s tua r ine a nd l a cus t r ine s he l lf i sh s p ec ies ( s ee b e low ) . A u s t rovenu s s t u tchbu ty i h a s b een p ropo sed a s p o ten t ia l ly a tr i sk o f b e ing a f f ec ted b y h a rd w a t e r i n N ew Z ea land ( McFadgen 1 972 :54 , I 978a :112 ) .

C ra s so s t rea g lomera ta c emen t s i t s e lf t o h a rd , e r o s ion r e s i s tan t r o ck s , p ref e r r ing v er t ica l a nd i n c l ined s u r f ace s , l y ing e i the r f l a t a ga ins t t h e r o ck w hen f ound i nd i s t r ibu ted n umbe r s , o r f o rm ing o y s te r c l u s te r s i nm a s s . T hey p r ef e r a s he l te r ed e nv i ronmen t , s u ch a s i n b ays o r a l ong r o cky h a rbou r s , g ood e xpo su re t os un l igh t , a nd a r e f o und a t tached t o r o ck s a bove t h e l e ve l o fs e t t l ing s i l t ( Mor ton a nd M i l le r 1 968 :406 ) . T h is s pec ie s f l ou r i shes i nh a rbou r s a nd t h in s i n n umbe r a s w ave a c t ion i n c rea se s ( Mor ton a nd M i l le r 1 968 :64 ) . Gas tropods V a r iou sg a s t ropod sw e re a l so e xp lo i ted b yp r eh i s to r ic Mao r i , s uch a s L une I la s maragda , C om ine l la s p . , a nd Amph ibo la c rena ta ( mud sna i l ) . A l l t h e se s pec ie s h ave b een u sed t o r a d ioca rbon d a te a r chaeo log ica l s i te s i n N ew Z ea land . Amph ibo la c r ena ta i sn o l o nge r u sed f o r d a t ing d ue t o i t s u n r e l iab i l i ty ( s ee C hap te r 3 ) . L une l la s ma ragda a r e f o und mo s t o f ten i nt i da l p oo ls a nd o n t h e s u rf ace o fr o cky s ho re p l a tf o rms w he re i tc an g raz e o n a l gae a nd k e lp ( Mo r ton a nd M i l le r 1 968 :202 -203) . T h i s h ab i ta t i s mode ra te ly s he l te red w i th t h er ocky c r ev ices a nd p oo l sp rov id ing c ove rf r om w ave a c t ion . A l though L une I la s ma ragda c an b e p r e sen t i nm uddy a r ea s ( s uch a s a mong s t Z o s te ra s p . a nd i n m ang rove s wamp s ) , t h ey p r ef e r r ocky s t ra ta . C om ine l la a d spe r sa l i ve i n an umbe ro fn i ches , f r om r o cky s ho re , t om uddy s and a nd s andy b eache s , a s l o ng a s t h e h a rbou r , b ay o r e s tua ry i s s he l te r ed ( Mo r ton a nd M i l le r 1 968 :398 ,490 ) . H e re t h ey s c avenge d ead o rgan isms . C om ine l la v i rga ta , mo re p r eda to r t h an s c avenge r , i n hab i t s am ode ra te ly s he l te red n i che l i v ing o n r o cky o rs i l ted r e ef s , a nd c an b ef ound i nt i da lp oo ls u nde r s t one s . A s w i th C om ine l la a d sper sa , C om ine l la v i rga ta c an

T he h a rd w a te r e f f ec t h a s b een o b served i n many o ve r sea s s t ud ie s o n t h e d a t ing o f m a r ine s he l l , p a r t icu la r ly f r om l a cus t r ine e nv i ronmen t s . D ye ( 1994 :55 ) h a s f o und g rea te r a ge d i sc repanc ie s b e tween s he l lf i sh s pec ies i n hab i t ing a l i me s tone c oa s t , t h an t h o se f r om n on -ca lca reou s g eo log ica l d epos i t s . B e rge r a nd Meek ( 1992 ) n o ted t h a t r a d ioca rbon d a te s o ft h e f r e shwa te rm o l lu sc A nodon ta c a l if orn ien s i s f r om t h e H umbo ld t R ive rb a s in s i nN evada , r e qu i re a n 1 870 ± 2 70 y ea r r e se rvo ir c o r rec t ion d ue t o a n i nf lux o f d ead c a rbon f r om d i sso lved P a leozo ic c a rbona te s t h rough w h ich t h e r i ve r f l owed . T h is w a s i nc on t ra s t t ot h e s ame g enu s b e ing d a ted i nt h e Mo jave R ive r b a s in s , s ou the rn C a l if orn ia , w he re t h e b a s in s i t s u pon ac a rbona te f r ee c ry s ta l l ine b ed rock ,t h e ref o re r e qu i r ing ar e se rvo i rc o r rec t ion o fo n ly 4 50 y ea r s . Ah a rdwa te re f f ec t i sa l so n o ted b y H e i r -N ie lsen e ta l . ( 1995 ) f o r D an ish F jo rd s . I n t h e L imf jo rd S ound i np a r t icu la r , t h e r e se rvo i r a ges w e re g r ea t ly i nf luenced b y D IC i nf lux ing f r om g round w a te r a nd s t reams . T he f j o rds s t ud ied s howed r e se rvo i r a ge s s pann ing 4 00 t o 9 00 y ea r s , d epend ing u pon l o ca l h yd ro log ica l a nd g eo log ica l c ond i t ions ( He i r -N ie lsen e t a l . 1 995 ) . A ravena e ta l . ( 199 1 :170 ) o b se rved t h e i nf luence o f" o lde r w a te r " o n t h e l owe r ing o f Al 4C a c t iv i t ie s i n af r e sh w a te r l a ke i nt h e P recamb r ian S h ie ld i nC anada . B ron ic e ta l . ( 199 1 :18 1182 ) c ompa red ' 4C a c t iv i t ie s o fp r e b omb k nown a ge c a rbona te d epos i t s a nd wood s amp le s t o d e term ine t h e m agn i tude o f t h e h a rd w a te r e f f ec t i n l a ke s ed imen t s i nt h e P l i tv i c e L ake s a r ea o fY ugo s lav ia . H e re t h e C a c t iv i ty o f w ood f r agmen t s i n l a ke s ed imen t s w e r e c ompa red w i th t h e a c t iv i ty o fs u r round ing l a ke s e d imen t s t o d e term ine t h e i n i t ia l ' 4C a c t iv i ty o ft h e l a ke s , a nd t h e ref o re 1 4

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CHAPTER 4

R ad ioca rbon D a t ing C ha rcoa l a nd Ma r ine S he l l

H igham 1 993 :12 1) . T h i s o rgan ic c a rbon , a l so k nown a s m e tabo l ic c a rbon , i s i n co rpo ra ted i n to t h e s he l l t h rough n u t r i t ion . D epend ing u pon t h e o r ig in o f t h e t e r re s t r ia l m a te r ia l , s he l l a ge sm ay b e i n c rea sed o rd ec rea sed .

g ene ra te a c o r r ec t ion f a c to r f o r f u tu re l a ke s ed imen t a ge d e te rm ina t ions . F on te s e ta l . ( 199 1 :196 197 ) o b se rved t h e i n f luence o f " o ld c a rbon" o n r a d ioca rbon a ge s o f t h e f r e shwa te r mo l lu sc C ard ium f r om H o locene l a cu s t r ine d epo s i t s i n ac onf ined a cqu if e r i nt h e N or thern S aha ra . T he a ge s w e re 2 000 y ea r s o l de r t h an e xpec ted , w i th t h e o l d c a rbon c om ing f r om " ver t ica l s e epage " f r om m ud s a tt h e b a se o f t h e a cqu if e r . G a rc ia e t a l . ( 1 99 1 :198 ) a ccoun t f o r t h e d i f f e rence o f r a d ioca rbon a ge s b e tween g eo log ica l d epo s i t s o fc a rbona te s a nd o rgan ic m a t te r f r om ap a leo lake a s b e ing d ue t o ah a rd w a te r e f f ec t . I na vo id ing t h e h a rd w a te r e f f ec t w hen d a t ing l am ina ted l a ke s e d imen t s , H a jda s e ta l . ( 199 1 :205 -206 ) u sed t h e AMS t e chn ique t o d a te m ac ro f o s s i ls s u ch a s l e ave s , n eed les a nd s e ed sf r om t r ee s . T h i s w a su nde r taken i n as ma l l S w is s f r eshwa te r l a ke o n as equence o f l a ke s ed imen t s r a ng ing f r om 6 , 000 12 ,000 y ea r s i n a ge ( Ha jda s e t a l . 1 99 1 :206 ) .

s ou rce d ep le ted i n ' 4C , s uch a s p ea t . I nt h is c a se , t h e 81 3C l e ve l t e nd s t o b ecome mo re n ega t ive . C onve r se ly , o rgan ic ma t te r w h ich i sc on tempo ra ry w i th t h e s he l lf i sh d u r ing i t s g row th m ay r e su l t i ns he l l a ge s w h ich a r e t oo y oung , w i th t h e 8DC l e ve l a l so mo re n ega t ive ( L i t t le 1 993 :468 ; H igham 1 993 :145 146 ) . T h i s i s b ecau se t h e o rgan ic ma t te r i s o f t e r re s t r ia l o r ig in , a nd s on o t e f f ec ted b yt h e o cean ic r e se rvo ir e f f ec t . H ence t h e a ge o f t h e c on tam ina t ing o rgan ic c a rbon w i l l b e c a . 4 00 y ea r s y ounge r t h an t h e c on tempo ra ry m a r ine s he l l . T he OC e f f ec t i sp o s s ib ly s pec ie s s p ec if ic a cco rd ing t o H igham ( 1993 :144 150 ; 152 153 ) , a s mo l lusc h ab i ta t w i l l d e term ine d eg ree o fp o ten t ia l e xpo su re t ot h is i nf luence .

U pw e l l ing

D ISCUSS ION AND CONCLUS IONS

U pwe l l ing o ccu r s w hen ' 4C -dep le ted c a rbon f r om t h e d eep o cean i sb rough t t ot h e m ixed l a ye r o cean s u rf ace t h rough u pwe l l ing s e a c u r ren t s , o f ten i n r e g ion s w i th p l ung ing c oa s ta l m a r ine s h e lve s . T he d ep le ted c a rbon m ay a l so b e u pwe l led f r om d i s so lv ing l i me s tone s ou rce s n ea r t o r i s ing s e a c ur ren t s . T h i s f a c to r m a in ly a f f ec t s o pen ma r ine a nd r o cky s ho re s he l lf i sh s pec ie s . K a ikou ra i nt h e S ou th I s land h a s b een a r gued a s ap o s s ib le r i sk a r ea f o ru pwe l l ing i nN ew Z ea land ( s ee A nde r son 1 99 1 :777 ) .

C ha rcoa l u sed t o r a d ioca rbon d a te N ew Z ea land a r chaeo log ica l s i t e s h a s b een i d en t if ied t o t w ig s o f s ho r t l i ved s pec ie s s i nce 1 976 t o r e duce t h e i nf luence o f i n bu i l t a ge . H oweve r , al a ck o fd a ta o n t h e a c tua l l o ngev i ty o fs ome t r ee a nd s h r ub s p ec ie s , a nd d ec id ing w he the r at w ig f r om a l o ng l ived t r ee s p ec ie s s hou ld b e a ccep tab le a s d a tab le c ha r coa l , s t i l l r a ise s c oncer n s w hen d a t ing t h is s amp le t ype . A n a dd i t iona l c oncer n i st h e d u rab i l i ty a nd d ecay o fv a r ious t r ee a nd s h rub s p ec ie s a f t e r d ea th . A s d u rab i l i ty a nd d ecay a r e s pec ie s - a nd e nv i ronmen t -dependan t , c e r ta in r e g ions o f N ew Z ea land m ay h ave h ad mo re s ou r ce s o f o l d w ood a va i lab le f o r p r eh i s to r ic a c t iv i t ie s t h an o t he r s . T he r i sk o f d a t ing t w ig w ood o f h igh i n bu i l t a ge i sp o s s ib ly g r ea te r , t h e ref o re , f o r a r chaeo log ica l s i te s i n c en t ra l O tago i n t h e S ou th I s land , t h an i ti sf o r s i te s i nt h e N e l son /Ma r lbo rough d i s t r ic t . A s t h i s a r ea o fi n qu i ry h a s n o t b een s t ud ied i nd e ta i l i nN ew Z ea land , t h ee f f ec to ft h is s ou r ce o fe r ro r o n c ha rcoa l r ad ioca rbon a ge s i sd i ff icu l tt oq uan t if ya tp r e sen t .

A n i n c rea se i n s h e l l a ge c ome s a bou t w hen t h e o rgan ic m a t te r f e d u pon i nt h e e s tua ry o r ig ina te s f r om a n a nc ien t

T he C a l if or n ia c oa s t l ine i s ap a r t icu la r ly p rob lema t ic r e g ion f o r u pwe l l ing , w he r e h i gh ly d ep le ted 3 ,1 4C l e ve l s h ave b een o b se rved b y D ruf f e l a nd W i l l iams ( 199 1) , S tu ive r a nd B raz iuna s ( 1993 :153 ) , F l e s sa e t a l . ( 1993 ) I n g ram ( 1994 ) a nd F l e ssa ( p e r s . c omm . I 4) .T h i s c oa s t l ine h a s s e en d r ama t ic s h if t s i nr e se rvo i ra ge s , r a ng ing f r om b e tween 2 00 y r st o5 00 y r s . T h is p henomenon h a s a l so b een i n ve s t iga ted b y R a smu s sen a nd R ahbek ( 1993 ) f o r G r een land , G o rdon a nd H a rkne s s( 1993 )f o rt h eA n ta rc t ic ,G lynn e ta l . ( 1983) f o rt h e G u lf s o fT ehuan tepec , P apagaya a nd P anama o n t h e P ac if ic c oa s t o f C en t ra l Ame r ica , K a shga r ian e ta l . ( 1994 ) f o r t h e I ndone s ian s eaway , We idman a nd J one s ( 1993 ) f o r G eo rge s B ank , F lo r ida , S ou thon e ta l . ( 1994 ) f o r t h e I nd ian O cean , a nd b y D r uf f e l a nd S ue s s ( 1983 ) f o rt h e P e ru C ur ren t . I th a s b een s ugge s ted t h a t u pwe l l ing m ay b e g eog raph ica l ly a nd t empo ra l ly v a r iab le d ue t os e a sona l a nd o t he r n a tu ra l e ven t s , s uch a s t h e Monsoon s e a son ( H igham 1 993 :137 138 ; K a shga r ian e ta l . 1 994 ) .

Mo s t o ft h e c h rono log ica l p rob lems o b se rved w i th t h eu se o f c ha r coa l c ome f r om s i te s w h ich h ave o n ly as i ng le c ha rcoa l a ge ( a s s e en i nC hap te r3 ) . A ga in , n o t a l o ft h e c ha r coa l w a s i d en t if ied i nt h e se s t ud ies . H igham ( 1993 ) a nd A nde r son e t a l .' s( 1996 )e x ten s ive d a t ing o ft h e S hag Mou th moa -hun t ing s i te , a r e t h e b e s t e xamp le s i nN ew Z ea land a r chaeo logy a t p r e sen to ft h ee f f ec t ive u se o fc ha r coa l i nr a d ioca rbon d a t ing . I nt h e se s t ud ie s , m u l t ip le s amp le s w e re i d en t if ied t ot w ig s o f s ho r t l ived s pec ie s p r io rt od a t ing , t h e r e su l t ing d a te s c l o se ly a g ree ing w i th a s soc ia ted m a r ine s he l l a ge s . B y u nde r tak ing mu l t ip le d a t ing , c ha rcoa l s amp les a f f ec ted b y i n bu i l t a ge wou ld s t and o u t f r om t h e r ema in ing p oo l o fd a te s , t h us t h e c ha r coa l c h rono logy i t s e lf w a s ac heck o n i n bu i l ta ge .

The Organ ic Carbon ( OC ) E f f ec t : A l tera t ions I n 5' 3C L eve ls T he i nf luence o f t e r r e s t r ia l o rgan ic m a t te r o n t h e a ge o f s he l lf i sh c an c au se d a te s t ob e e i the r t o o o l d o r t oo y oung .

B y i n ve s t iga t ing t h e o r ig ins o fc a rbon u s ed b y b i va lve s a nd g a s t ropod s d u r ing s he l l b u i ld ing , a nd u nde r s tand ing t h e i r h ab i ta t s a nd l i f eway s , w e m ay i d en t if y w ha t e nv i ronmen ta l a nd g eo log ica l f a c to r s m ay i nf luence t h e r a d ioca rbon d a t ing o fs he l lf i sh c ommon ly f ound i nN ew Z ea land a r chaeo log ica l s i te s .

1 3

C on t r ibu t ion b y o rgan ic c a rbon c an b e d e tec t ed b y l ow 8 C l e ve ls , u n l ike c on tam ina t ion b y t h e h a rd w a te r e f f ec t o r u pwe l l ing . T he s ou r ce o f o rgan ic c a rbon c ome s f r om t e r r e s t r ia l o rgan ic m a t te r s uch a s p l an t d e t r i tu s , d i a toms , p ro tozoa , k e lp , p hy top lank ton , h umu s o r p ea t , c a r r ied b y r i ve r s i n to a n e s tua r ine e nv i ronmen t ( L i t t le 1 993 :468 ;

F o r t h e s of t s ho re h a rbou r a nd e s tua r ine b iva lve s pec ie s P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbwy i a nd V enerup i s l a rg i l l ie r t i , l i v ing i n b o th p ro tec ted a nd e nc lo sed b eaches , t h e t wo m a in r i sk s c ome f r om t h e h a rd w a te r e f f ec t a nd

1 4 D r . K .F l e s sa , D epa r tm en to fG eo s c ience s , U n ive r s i t yo fA r izona , T uc son ,U SA .

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CHAPTER 4

R ad ioca rbon D a t ing C ha rcoa l a nd Ma r ine S he l l

t e r re s t r ia l o rgan ic c a rbon s ou r ce s . T he s of t s ho re b each o pen c oa s ts pec ie s , s uch a sP aph ie ss ub t r iangu la tum , a r e p robab ly o n ly a t r i sk o f b e ing e f f ec ted b y u pwe l l ing d ue t o t h e i r i s o la ted h ab i ta t i nc l ean s ands a nd e xpo su r e t o u n she l te red w ave a c t ion . T he r o cky s ho re h a rbour a nd o pen c oa s t s pec ie s My t i lu s e du l i s a o teanu s , P e rna c ana l icu la , C ra s so s t rea g lomera ta , L une I la s ma ragda , C om ine l la a d spe r sa , a nd C om ine l la v i rga ta m ay a l b e a f f ec ted b y h a rdwa te ro r ig ina t ing d i rec t ly f r om d i s so lu t ion o f t h e r ock s t ra ta u pon w h ich t h ey l i ve . H igh r i sk a r ea s w ou ld b e l i me s tone r o cky s ho re s a nd h i gh ly c a lca reou s s ed imen t s . A dd i t iona l ly , u pwe l l ing m ay a l so b e a s ou rce o fo ld c a rbon w he re i n hab i ted r o cky s he lve s h ave a p l ung ing c oa s t l ine o ro f f sho re o cean t r ench . P o ten t ia l s ou rce so fe r ro r i nd a t ing c ha r coa l a nd ma r ine s he l l f r om a r chaeo log ica l s i tes h ave b een p r e sen ted a bove . I fa n a r chaeo log ica l s i te s amp led f o r d a t ing h a s n o t b een p o s t d epo s i t iona l ly d i s tu rbed , t h en t h e se f a c to r s m ay b e p ropo sed a s p o s s ib le r e a son s f o r d i sag reemen t s b e tween c ha r coa l a nd ma r ine s he l l r a d ioca rbon a ge s . T he n ex t c hap te r e xam ines a no the r c ons ide ra t ion i nt h e u se o f m a r ine s he l l f o r d a t ing , t h e m a r ine r e servo i rc o r rec t ion .

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CHAPTER 5

RESERVO IR CORRECT IONS

I NTRODUCT ION

T oc a lcu la te R ( t ) ,e ach m e thod u se st h e f o rmu la :

T he c a l ib ra t ion o f ma r ine s he l l c onven t iona l r ad ioca rbon d a tes h a s c hanged d rama t ica l ly o ve rt h e p a s t 1 4 y ea r s . P r io r t o 1 986 , m a r ine s he l l CRA s w e r e c a l ib ra ted b y s ub t rac t ing a c oun t ry spec if ic r e se rvo i r c o r rec t ion ( R ) , a nd c a l ib ra t ing t h e r e su l t ing a ge u s ing a n a tmo sphe r ic c a l ib ra t ion c urve . S t u ive r e t a l . ( 1986 ) t h en d eve loped a n a l te rna t ive m e thod o f c a l ib ra t ion , t h rough t h e u se o f amode l led m a r ine c u rve a nd a pp l ica t ion o f al o ca l r e se rvo i r c o r rec t ion c a l led AR . T h is c hap te r d e sc r ibe s h ow m a r ine s he l l CRAs a r e c a l ib ra ted u s ing t h e r e servo ir c o r rec t ion ( R ) t e chn ique , a nd t h e mo re r e cen t S t u ive r e t a l . ( 1986 , 1 993 ) mode l led ma r ine c u rve c a l ib ra t ion m e thod . P rob lem s a s soc ia ted w i th t h e a pp l ica t ion o fe ach m e thod a r e p re sen ted , a sw e l l a s ad e ta i led r e v iew o f v a r iou ss t ud ie so n AR s i nce i t si n t roduc t ion i n1 986 .

Af t e r mC i sp roduced i n t h e a tmo sphe re , i t s m ix ing a nd c oncen t ra t ion i n t he v a r iou s r e se rvo i r s i s n o t e qua l . R ep len i shmen to f' 4C i nt h e m ixed l a ye ro cean ( 75m ) i ss l ow c ompa red t o t h a t o f t h e a tmo sphe r e . Whe rea s t h e " r e s idence " t ime o f ac a rbon a t om i sa bou t 5y ea r s i n t h e a tmo sphe re , t h e d eep o cean c an c on ta in c a rbon a t oms w h ich h ave b een p r e sen t f o rt h ou sand s o fy ea r s . T he m ixed l a ye r o cean c on ta ins a' 4C c oncen t ra t ion t h a t i si n te rmed ia te b e tween h i ghe r a tmo sphe r ic l e ve l s a nd d ep le ted d eep o cean w a te r . T h i s r e su l t s i nt h e m ixed l a ye r o cean h av ing a n a ppa ren t ' 4C a ge o f c a . 4 00 y ea r s , a nd i s k nown a s t h e r e servo i r e f f ec t ( A i tken 1 990 :64 ) . T he r e se rvo ir e f f ec t t h e ref o re c au se s m a r ine s he l l a ge s t oa ppea r c a . 4 00 y ea r so l de rt han c on tempo ra ry t e r re s t r ia l m a te r ia l .

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c ompa r ing a ma r ine s he l l r a d ioca rbon a ge c o l lec ted i n c a lenda r y ea r ' t ' w i th a n a tmo sphe r ic r ad ioca rbon a ge t a ken f r om a t r ee r i ng r e co rd o f t h e s ame y ea r o f c o l lec t ion ;

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o r b y c ompa r ing t h e a ge d i f f e rence b e tween p a i red c ha r coa l a nd ma r ine s he l l r a d ioca rbon d a te s f r om t h e s ame a r chaeo log ica lp rovenance .

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T he r e servo i r c o r rec t ion R ( t ) i ss pec if ic t ot h e c a lenda r y ea r f o r w h ich i th a s b een d e te rm ined . T o s imp l if y t h e c o r rec t ion o f ma r ine s h e l l s f o r c a l ib ra t ion o n a n a tmo sphe r ic c urve , m any l a bo ra to r ie s d e te rm ine a m ean r e se rvo i r c o r rec t ion c a l led R o r R * , d e r ived f r om t h e a ve rag ing o f R ( t ) d e term ina t ion s ( a s p r e sen ted i n T ab le 5 . 1) . H oweve r , w he rea s s e r ie s o fR ( t ) v a lue s r ef l ec t v a r ia t ions i nt h e m a r ine r e se rvo i rt h rough t ime , Rd oe sn o t .

T he mo s t c ommon m e thod e mp loyed t od e r ive R ( t ) f o rN ew Z ea land h a s b een t ou se m a r ine s he l l s w i th ak nown y ea r o f c o l lec t ion . R af t e r e t a l . ( 1972 ) c a lcu la ted a m a r ine s he l l r e se rvo i r c o r r ec t ion ( R ) o f 30 y ea r s f o r N ew Z ea land u s ing t h is m e thod . T h i s f i gu r e , k nown a st h e N ew Z ea land Ma r ine S he l l S tanda rd ( NZMSS ) , w a s d e r ived t h rough m ea su r emen t o f t h e ' 4C a c t iv i ty o f s h e l l c a rbona te o f modern c ock le s ( Pro to thaca c ra s s i te s ta ) g a the red f r om P ounawea , O tago , i n 1 955 ( Raf t e re ta l . 1 972 :627 ) . T he NZMSS w a s r e -ca lcu la ted b y McFadgen i n 1 978 , b y d e term in ing t h e r a d ioca rbon a c t iv i t ie s o fs i x a dd i t iona l s he l l s amp le s c o l lec ted l i ve b e tween 1 923 a nd 1 957 , f r om a v a r ie ty o f l o ca t ions a r ound N ew Z ea land ( i nc lud ing P ounawea ) ( McFadgen 1 978b , 1 982 ) . T h i s w a s u nde r taken t o t e s t w he the r o r n o t t h e NZMSS a pp l ied t o a l l a r ea s o f c oa s ta l N ew Z ea land ( McFadgen 1 978b :3 11) . T he s pec ie s u sed f o r t h i s a na ly s is w e r e P ro to thaca c ra s s i te s ta , C h ione s t u tchbu ly i , P aph ie s v en t r i co sum , P aph ie s s ub t r iangu la tum a nd Do s in ia a nu s . McFadgen ( 1978b :313 ) f ound t h e m ean r a d ioca rbon a c t iv i ty o f h i s s i x h i s to r ica l s amp le s ( R ) ( af te r c or rec t ion f o r t h e i n du s t r ia l e f f ec t ) w e re s l igh t ly d i f f e ren t f r om t h e v a lue p r e sen ted b y R af t e r e t a l . ( 1972 ) , a nd p ropo sed t h a t t h e NZMSS s hou ld b e f u r the r c o r r ec ted b y s ub t rac t ing 5 y ea r s f r om r e po r ted d a te s ( 1978 :311 , 3 13 ; 1 982 :384 ) . ( Th i s i n c rea sed t h e NZ MSS t o 3 85 y ea r s , s e e T ab le 5 . 1) . L aw ( 1984 ) r e v i sed t h e R af t e r e ta l . ( 1972 ) a nd McFadgen ( 1 978b ) c a lcu la t ions a nd b e l ieved t h a t 3 28 y ea r s f o rt h e P ounawea s t anda rd w a s amo re e xa c t f i gu re . H e a l so r e a s ses sed McFadgen 's ( 1 978 ) d a ta , a nd d e r ived ac o r rec t ion o f5 9y ea r s ,w h ich i n c rea sed t h e NZ MSS t o3 87 y ea r s .

R ad ioca rbon l a bo ra to r ie s w o r ldw ide h ave c a lcu la ted l o ca l r e servo i r c o r rec t ions w h ich a r e a pp l icab le t o ma r ine s he l l r a d ioca rbon a ge s f o r t h e i r p a r t icu la r r eg ion o f o cean ( s ee S t u ive r a nd P o lach 1 977 :356 -357 ; D eevey 1 984 :3 ,5 ) . T hese l o ca t ion s p ec if ic c or rec t ions a r e t h en a pp l ied t ot h e i rm a r ine s he l l r a d ioca rbon d a te s b ef o r e c a l ib ra t ion . T he r e se rvo ir c o r rec t ion R (0 1 5 i sd e r ived i nt h ree w ay s , e i the rb y : r a d io ca rbon d a t ing am a r ine s h e l l s amp le o fk nown y ea r o f c o l lec t ion ( p ref e rab ly s h e l l c o l lec ted b ef o r e 1 950 ) a f t e rc o r rec t ion f o rt h e i n du s t r ia l e f f ec t ;

w he re P i st h e m a r ine s he l l r a d ioca rbon a ge , a nd Q i se i the r t h e k nown c a lenda r a ge o f c o l lec t ion , o r t h e a pp rop r ia te ly c orec ted c ompa rab le t e r re s t r ia l r a d ioca rbon a ge .

T HE N EW Z EALAND MA R INE S HELL ST ANDARD A ND CA L IBRAT ION O FN EW Z EALAND A RCHAEOLOG ICAL S AMPLES

T HE R ESERVO IR E FFECT A ND R ESERVO IR C ORRECT IONS

•

R ( t ) = P-Q

Ri s ac u lm ina t ion o fR ( t )v a lue s ,s e eb e low .

3 7

R eservo ir C o r rec t ions

C HAPTER 5

O cean

R e servo ir C orrec t ion / Mar ine S he l l S tandard

R ef erence

A us t ra l ia

4 50 y ea r s

G i l le sp ie a nd P o lach 1 979 , L aw 1 984

B a l t ic S ea

3 20 y ea r s

Mangerud a nd G u l l ik sen 1 975

C o s ta R ica

4 65 y ea r s

G lynn e ta l . 1 983

E a s tern J u t land

3 20 y ea r s

O l s son 1 983

S ou thern O cean

1 300 y ea r s

H i l le rp er s . c omm2 b

D enma rk

4 10 y ea r s

R a smussen p e r s . c omm ."

F rance

4 00 y ea r s

F or t in p e r s . c omm2 8

V anua tu

4 07 y ea r s

B ur rp e r s . c omm .

T rop ica l

3 28 y ea r s

L aw 1 984

F i j i

4 12 y ea r s

L aw 1 984

S p i t sbe rgen

4 25 y ea r s

O ls son 1 983

S wed ish Wes tC oas t

3 40 y ea r s

O ls son 1 983

N o rway

4 40 y ea r s

Mange rud a nd G u l l iksen 1 975

S p i t sbe rgen

5 10 y ea r s

Mange rud a nd G u l l iksen 1 975

A rc t ic C anada

7 50 y ea r s

Mangerud a nd G u l l ik sen 1 975

N ew Z ea land

3 28 y ea r s

L aw 1 984

N ew Z ea land

3 30 y ea r s

R af te re ta l . 1 972

N ew Z ea land

3 36 y ea r s

J ansen 1 984

N ew Z ea land

3 85 y ea r s

McFadgen 1 978

N ew Z ea land

3 87 y ea r s

L aw 1 984

N ew Z ea land

4 30 y ea r s

A nde r son 1 991 , I GNS r e co rd s .

1 9

T ab le 5 . 1 . R ese rvo i rc or rec t ions /ma r ine s he l l s t anda rd s f r om o cean ic r e g ions a round t h e wo r ld .

T h is f i gure a l te red a ga in i n1 984 w i th t h e I GNS p roduc ing a NZ MSS o f3 36 y ea r s ( J ansen 1 984 ) ( i t i sn o t c l ea r w he the r t h e I GNS a dv ised r e sea rche r s t o a dd o n af u r the r 5 5 o r 5 9 y ea r s t o t h is f i gure b a sed o n McFadgen ( 1978 ) a nd L aw ' s ( 1984 )c a lcu la t ions ) . T he N ew Z ea land e xamp le i lus t ra tes t h a t a l though t h e c a lcu la t ion o fa n a ve rage R v a lue w a s i n tended t o s imp l ify t h e c or rec t ion o f ma r ine s he l l CRAs , c hanges i nt h is v a lue o ve r t ime h a s h ad s i gn if ican t e f f ec t s o n t h e p r eh is to r ic ma r ine s he l l r ad ioca rbon c hrono logy ( s ee A nde r son 1 991 :782 ) . F o re xamp le , o ne R v a lue b r ief ly a pp l ied t oN ew Z ea land ma r ine s he l l r a d ioca rbon d a te s b e tween 1 955 a nd 1 959 w a s 4 30 y ea r s ( s ee I GNS s amp le r e co rd f o rm R 192 / 15 , a nd A nder son 1 991 :782 ) . F o r New Z ea land , s i x m a r ine s he l l s t anda rds h ad b een d e r ived o r r ef ined b e tween 1 955 a nd 1 984 , t h ree b y t h e I GNS l a bo ra to ry a nd t h ree b y a r chaeo log is t s . T hese c hanges h ave b r ough t a bou t c onf us ion i n N ew Z ea land a r chaeo logy , mak ing i td i f f icu l t , i f n o t i n va l id , t o c ompa re r e se rvo ir c o r rec ted d a te s o b ta ined a t d i f f e r ing t ime s . T he s ho r t d u ra t ion o f N ew Z ea land p r eh is tory , makes t h e 1 00 y ea r v a r ia t ion ( 3 30 -4 30 y ea r s ) i n t h e NZ MSS e ven mo re s i gn if ican t .

I fa r chaeo log is t s r equ ire a n a ccura te a pp ra isa l o ft h e a ge o fa s i te wh ich h a s b een d a ted o ve r an umbe ro fy ea r s b y ma r ine s he l l , t hen t h is c an o n ly b e a ccomp l i shed b y o b ta in ing t h e o r ig ina l CRAs f r om t h e l a bo ra to ry , a nd t h en a pp ly ing a s i ng le r e se rvo ir c or rec t ion b efo re c a l ib ra t ion . McFadgen ' s ( 1978b ) r e servo i r c or rec t ion o f3 85 y ea r s c an b e c ons ide red t h e mo s t a pp l icab le f o r N ew Z ea land a tp resen t , d ue t o t h e n umber o fR ( t ) c a lcu la t ions e mp loyed i nd e r iv ing h i s f i na l R v a lue . Howeve r , a s n o ted a bove , af i xed R d oes n o t t a ke i n to a ccoun tc hanges i nR ( t )t h rough t ime , i ft h ey o ccur red . A NE W M AR INE SHELL CAL IBRAT ION METHOD The Box D iffus ion a nd G loba l Carbon Mode ls S tu ive r , P ea r son a nd B raz iuna s ( 1986 :980 ) r e cogn ised t h e p rob lems a s soc ia ted w i th a f i xed , c oun t ry -spec if ic R v a lue . T he ' 4C c oncen t ra t ion o ft h e m ixed l a ye r o cean d epends o n i t s e xchange r a te w i th t h e a tmo sphe re , a nd w i th t h e ' 4C d ep le ted d eep o cean . T he se e xchange r a tes , t hough , c an c hange t h rough t ime b ecause o ff l uc tua t ions i na tmosphe r ic 1 4C , o r i n crea sed s t orm iness . Af i xed R c o r rec t ion , s ub t rac ted f r om a ma r ine s he l l CRA t o g ive ar e se rvo ir c or rec ted a ge , c ou ld t he ref o re r e su l t i ne r roneous c a l ib ra t ions .

1 6

D r . A . H i l le r , A rbe i t sg ruppe P a laok l ima to log ie ,Q ua r ta rzen t rum d e rU n ive r s i ta tL e ipz ig , P ermo se r s t rabe , G ermany .

1 7

P rof . K . R a smu s sen , C a rbon 14 D a t ing L abo ra to ry ,N a t iona l Mu seum a nd G eo log ica l S ur vey o fD enma rk , C openhagen , D enma rk .

1 8

P .F o r t in ,C en t r ed eD a ta t ion p a rl eR ad ioCa rbone , U n ive r s i t eC laude B e rna rd L yon , V i l leu rbanne C edex F rance .

1 9

D r . G . B u r r , A r izona AMS F a c i l i ty , T he U n ive r s i ty o fA r izona ,T uc son A r izona , U SA .

3 8

CHAPTER 5

R ese rvo ir C o r rec t ions

S t u ive re ta l . ( 1 986 :980 ) n o ted t h a t r e se rvo i r a ge s h ave b een d e term ined b y r a d ioca rbon a ge a na ly s i s o fm a r ine s he l ls o f k nown d a te o fc o l lec t ion , a f te r c o r rec t ion f o r t h e i n du s t r ia l a f f ec t . H oweve r ,t h is m e thod ,w h ich u s e st h e e qua t ion 1 950 X( whe re 1 950 i st he k nown d a te o fc o l lec t ion o ft h e s amp le a nd X i st h e c onven t iona l r a d ioca rbon a ge o f t h e s he l l ) , a s sume s ac on s tan t a tmo sphe r ic l e ve l o f' 4C , a nd t h a t t h e ' 4C a ge ( X ) c an b e d i rec t ly s ub t rac ted f r om t h e c a lenda r d a te ( S tu ive re ta l . 1 986 :980 ) . S t u ive r e ta l . ( 1 986 :980 ) b e l ieved t h a t as e cond m e thod f o r c a l ib ra t ing m a r ine s he l l r a d ioca rbon a ge s w a s r e qu i red , w h ich w ou ld t a ke i n to a c coun t c hange s i nt h e r e se rvo i r a ge o f t h e m ixed l a yer t h rough t ime . Whe rea s t h e o r ig ina l p roces s d e r ived R ( t ) , s ub t r ac ted t h is f r om t h e m a r ine s he l l CRA , a nd c a l ib ra ted t h e r e su l t o n a n a tmo sphe r ic c u rve ( s ee a bove ) , t h e s e cond m e thod w ou ld p roduce a m a r ine c a l ib ra t ion c ur ve t ha t t o ok i n to a c coun t t h e t empo ra l v a r iab i l i ty o fR ( t )( S tu ive re ta l . 1 986 :980 ) .

T he b ox d i f f us ion m ode l d eve loped b y S t u ive r e t a l . ( 1986 :981) , c a l led t h e G loba l C a rbon Mode l ( GCM ) , u sed C a tmo sphe r ic d a ta f o r t h e p e r iod AD 1 950 t o 7 746 BC ( l a te r , S tu ive r a nd B raz iuna s ( 1993 ) e x tended t h e mode l t o 1 0 ,000 BC , i n corpo ra t ing c o ra l -ba sed ' 4C d a ta f o rt h e p e r iod 1 0 ,000 -9 400 BC ) . T he G loba l C a rbon Mode l s e t p a rame te r s f o ra tmo sphe r ic CO , c oncen t ra t ion , o cean ic C c oncen t ra t ion , t h e a moun to fCi nt h e b i o sphe r e , r e s idence t ime s i nt h e s hor t a nd l o ng te rm r e se rvo i r s , g a s e xchange r a te F b e tween t h e a tmo sphe re a nd m ixed l a ye ro cean , a nd t h e v e r t ica l d i f f u s ion c oeff ic ien t K > f o r t h e d eep o cean ( s ee S tu ive r e t a l . 1 4

1 986 :981) . F rom t h i s m ode l , ab i -decada l mode l led ma r ine c a l ib ra t ion c urve w a s c on s t ruc ted f o r t h e m ixed l a ye r o cean , f o rt h e p e r iod AD 1 950 t o7 746 BC ( s ee S tu ive r e ta l . 1 986 : F igu re s 3a nd 5 ) . A s t h e m ixed l a ye r mode l led m a r ine c u rve t ook i n to a ccoun t s ho r t te rm p er tu rba t ion s i n a tmo sphe r ic C, v a r iab i l i ty i nr e se rvo i r a ge s i nt h e m ixed l a ye r t h rough t ime w e re a ccoun ted f o r . S t u ive re ta l . ( 1986 :98 1) n o ted , f o r e xamp le , t ha t d u r ing t h e AD 1 950 t o7 746 BC p e r iod , s hor t t e rm p er tu rba t ions h ave o ccu r r ed e spec ia l ly d u r ing t h e 2 00 9 00 BC p e r iod . D u r ing t h i s p e r iod , a f i xed r e servo i r c o r r ec t ion n orma l ly u sed f o r o t he r t ime p e r iod s m ay b e i n app l icab le . 1 4

Ab ox -d if f us ion mode l ,b a sed o n O e schge re ta l . ( 1975 ) , w a s d eve loped t os imu la te g l oba l c a rbon e xchange ( S tu ive r e ta l . 1 986 :980 ) . T he O eschge re ta l . ( 1975 )B ox D if f u s ion Mode l e xp la in s t h e m ovemen t a nd d i s t r ibu t ion o f ' 4C t h rough t h e a tmo sphe r e , b i o sphe re , m ixed l a ye r o cean , a nd d eep o cean r e se rvo i r s . I t i s s im i la r t o o t he r b ox mode l s i n t h a t i t c ons ide r s p a rame te r s s u ch a s t h e a tmo sphe r ic CO , p roduc t ion r a te ,t h ickne s so ft h em ixed l a ye ro cean r e se rvo i r , CO , c oncen t r a t ion i n t h e d eep o cean , e xchange c oeff ic ien t b e tween a tmo sphe r ic a nd m ixed o cean ' 4C , a nd r e s idence t ime s o f 1 4C i n t he v a r iou s r e servo i r s ( Oe schge r e t a l . 1 975 :171174 , 1 84 ) . H oweve r , O e schge r e ta l . ( 1975 ) n o ted t h a t a l though b ox mode l s d i d e xp la in t h e l o ng t e rm movemen t a nd d i s t r ibu t ion o f ' 4C t h rough t h e v a r ious r e se rvo i r s , t h ey w ere n o t s e n s i t ive e nough t oi l us t ra te s hor t t e rm p er tu rba t ions , s uch a st h e i nf lux o ff o s s i l f u e l o rn uc lea r C ( Oeschge r e t a l . 1 975 :168 169 ) . T he m ixed l a ye r a nd d eep o cean c ou ld b e p a r t icu la r ly a f f ec ted b y s udden ' 4C i nf luxe s , a nd s os pec if ic m ode l l ing w a sr e qu i red . 1 4

O eschge re ta l . ( 1975 ) b e l ieved t h a tt h e d eep o cean r e ser vo i r c ou ld b e v i ewed a s ad i f f u s ive m ed ium , r a the rt h an a s aw e l l m ixed b ox ( a s c ons ide r ed b y p r ev iou s b ox mode ls ) . T hey t h e ref o re p ropo sed u se o f t h e p a rame te r K , w h ich r e p re sen ted a c ons tan t v e r t ica l e ddy d i f f u s iv i ty w i th in t h e d eep o cean r e se rvo i r . T h i s v a lue w a s c a lcu la ted u s ing m ea su r ed d a ta o n c hange s i np r e -bomb 1 4C /1 2C r a t io s w i th o cean d ep th f o r t he A t lan t ic a nd P ac if ic o cean s ( s ee O e schge r e ta l . 1 975 :174 176 ) . O e schge r e ta l . ( 1975 :176 ) a l so c a lcu la ted a n e xchanee c oeff ic ien t b e tween t h e a tmo sphe re a nd m ixed o cean 4C ( kam ) ( t he c a lcu la ted v a lue

T he m ixed l a ye r c a l ib ra t ion c u rve g ene ra ted b y S t u ive re ta l . ( 1986 , 1 993) , a l low s t h e c onve r s ion o f ama r ine s h e l l CRA t o y ea r s c a l AD . T he a ve rage r e servo i r c o r rec t ion f o r t h e w o r ld m ixed l a ye ro cean g ene ra ted b yt h e GCM i s3 73 y ea r s . H oweve r , S tu ive r e ta l . ( 1 986 :982 ; 1 993 :138 ) n o te t h a t t h i s a ve rage c o r rec t ion r e su l t s f r om t h e p a rame te r s c ho sen f o r t h e i r mode l , a nd a l though t h e mode l r e f lec t s c hange i nR ( t ) t h rough t ime f o r t h e w o r ld m ixed l a ye r o cean , i td oe s n o t t a ke i n to a ccoun t r e g iona l v a r ia t ions i no cean r e se rvo i r a ge s . T h i s i s c aused b y r e g iona l o cean ic p roce s se s , s uch a s u pwe l1 i n g o f ' 4C d ep le ted w a te r s , a nd w hen r eg iona l a tmo sphe r ic ' 4C a c t iv i ty d i f f e r s f r om g loba l ly o b se rved a c t iv i ty ( S tu ive r e t a l . 1 986 :982 , 1 993 :138 ) . T h i s c ons tan t r e se rvo i r d i f f e rence ( AR ) b e tween t h e r e g iona l a nd mode l led w o r ld o cean c urve i s , ( a s af i r s t a pp rox ima t ion ) n o t t ime d ependen t , a nd s o c an b e c a lcu la ted f o r ar e g ion a nd s ub t rac ted f r om ma r ine s h e l l CRA , b ef o re c a l ib ra t ion o n t h e m ixed l a ye r mode l led m a r ine c a l ib ra t ion c u rve . Ca lcu lat ion o f AR T he re a r e t wo m e thod s b y w h ich AR m ay b e c a lcu la ted f o r u se o n t h e S tu ive r e t a l . ( 1 986 ; 1 993) mode l led ma r ine c a l ib ra t ion c urves . T he f i r s t r e qu i r e s t h e u se o f p r e -1950 s he l l o f k nown h i s to r ic a ge , a nd t h e s e cond e mp loy s d a ted t e r re s t r ia l /ma r ine s he l l p a i r s f r om p r eh i s to r ic c on tex t s . T he f i r s t me thod w a s u sed i n i t ia l ly b y S tu ive r e ta l . i n 1 986 t op roduce t h e f i r s tw o r ldw ide r e g iona l AR c o r rec t ion s . F o ra p a r t icu la r r eg ion , an umbe r o f m a r ine s he l l s amp les o f k nown h i s to r ic a ge ( AD X ) , c o l lec ted p r io r t o 1 950 , a r e d a ted . T h is r ad ioca rbon a ge i st e rmed P . T he m ixed l a ye r o cean C a ge , Q , f o r AD X , i st h en f ound u s ing t h e mode l c a lcu la ted c onven t iona l ' 4C a ge c u rve f o r t h e m ixed l a ye r

a g ree ing w i th t h o se d e r ived i np r ev iou s b ox mode l s ) , t ou se i na s soc ia t ion w i th K . O e schge r e ta l . ( 1975 ) e xp la ined t h a t b y i n co rpo ra t ing t hese p a rame te r s i n to t h e i r B ox D if f u s ion Mode l , s ho r t t e rm ' 4C p e r tu rba t ion s i nt h e m ixed l a ye r a nd d eep o cean r e se rvo i r sc ou ld b ee f f ec t ive ly s imu la ted .

1 4

O eschge r e ta l . ( 1975 ) u s ed t h e i r B ox D if f u s ion Mode l t o s imu la te v a r iou s k nown s ho r t te rm ' 4C p er tu rba t ions i nt h e m ixed l a ye r o cean . O ne e xamp le c on s ide red t h e i n c r ea se i n b omb ' 4C i nt h i sr e servo i rb e tween 1 956 a nd 1 969 ( Oe schge r e ta l . 1 975 :186 188 ) . I tw a s f o und t h a tt h e i r c ompu te r mode l s ucce s sf u l ly s imu la ted t h i s s ho r t te rm i n f lux o f C , a nd w a s i na g reemen tw i th a c tua l b omb ' 4C i n c r ea se s .

o cean ( F igu re 5 . 1) . T he AR f o rt h e s amp le i st h en c a lcu la ted b y : AR =P—Q

3 9

R ese rvo ir C or rec t ions

CHAPTER 5

F igu re 5 . 1 . Mode l led ma r ine c onven t iona l r a d ioca rbon a ge c urves f o r t h e m ixed l a ye r a nd d eep o cean . T he m ixed l a ye rc u rve i su sed t oc onver t ac a lenda r ma r ine s he l l d a te ( AD X ) i n to amode l led ma r ine a ge ( Q ) f o r AR c a lcu la t ion ( f rom S tu ive re ta l . 1 986 :994 ) .

REG ION

SA MPLE NO .

H ISTOR ICAL AGE ( c a l AD )

CONVENT IONAL SA MPLE 4 16 + 4 2

57 ±4 2

1 4C

AGE ( '4C YRS B P )

AR (1 4C Y RS B P )

N ew Z ea land

-

1 923

N ew Z ea land

-

1 925

3 71 ± 5 0

103 ±5 0

N ew Z ea land

-

1 949

2 10 ± 4 1

2 80 ±4 1

N ew Z ea land

I NS n o . R .42

1 955

4 46 ± 4 2

4 4 +4 2

WE IGHTED MEAN OF ABOVE 3 S AMPLES (W ITH 280 ± 4 1 EXCLUDED ) S CATTER I N UN WE IGHTED MEAN I S2 0 YR

6 5 +2 5

T ab le 5 . 2 . O r ig ina l AR v a lue f o rN ew Z ea land c a lcu la ted b y S tu ive re ta l . ( 1986 :1020 -1021) .

T h is c or rec t ion i st h en a pp l ied t o ma r ine s he l l CRA d ur ing c a l ib ra t ion u s ing t h e S tu ive r e t a l . ( 1986 , 1 993) mode l led

T he s e cond me thod f o r c a lcu la t ing AR e mp loy s t e r res t r ia l /ma r ine s he l l p a i r s ( S tu ive r e t a l . 1 993) . T h is

ma r ine c a l ib ra t ion c urve s . S ugges ted AR c or rec t ions ( p re sen ted i n 1 986 ) f o r v a r ious r eg ions o f t h e w o r ld a nd c a lcu la ted u s ing m e thod o ne , c an b e s een i nf i gu re 5 . 2 . T he

me thod i su sed t oc a lcu la te AR f o rt h ea r chaeo log ica l s i te s i n t h is s t udy . A s w e a r e d e term in ing ar e se rvo ir c o r rec t ion f o r t h e ma r ine e nv ironmen t , t he t e r re s t r ia l ( a tmo sphe r ic ) r ad ioca rbon a ge i sf i r s t c onver ted t o am ode l led m a r ine a ge u s ing a c onve r s ion c urve ( F igure 5 . 3 ) . T h is c u rve p l o t s mode l led m a r ine r ad ioca rbon a ge s a ga ins t a tmosphe r ic r ad ioca rbon a ges . T he d e r ived m ode l led ma r ine a ge i s t e rmed t h e " known h i s to r ic a ge" ( Q at )a nd i sc ompa red t ot h e

w e igh ted mean AR v a lues f o re ach r eg ion w e re d e r ived f r om s e t s o f AR d e term ined f o r i n d iv idua l s he l l s amp les . T he 1 986 N ew Z ea land d e term ina t ion c an b e s e en i nt ab le 5 . 2 . T he 1a v a lue a s soc ia ted w i th t h e AR v a lue w a s d er ived f r om t h e w e igh ted m ean o f t h e ' 4C a ges . H oweve r , S t u ive r e t a l . ( 1986 :982 ) n o te t h a t t h e l a e r ro r f o r t h e mean AR v a lue c ou ld a l so b e c a lcu la ted a s a n u nwe igh ted o r ' s ca t te r ' mean w hen t h e ' 4C a ges a r e t a ken a s ad a ta s e t ( Tab le 5 . 2 ) . S t u ive r e t a l . ( 1986 :982 ) u sed t h e l a rges t o f t he t wo s i gma

p a ired ma r ine s he l l CRA

AR i st h e ref o re c a lcu la ted

d e term ina t ion s f o r t h e i r AR c or rec t ions , a nd a s s igned a r e g iona l r e ser vo i r c or rec t ion f o r N ew Z ea land o f 6 5 ±2 5 Cy ea r s B P( a so pposed t o65 ± 2 0 ) .

T he AR s t anda rd e r ro r i sf ound u s ing t h e f o rmu la ( s ee L i t t le 1 993 :464 ; H igham 1 993 :126 ) :

u s ing t h e f o rmu la : AR = P , , . —Q . ,

1 4

AR a to ta l =. ` ka i n a2

4 0

1 ;1 2)

R e se rvo i rC o r r e c t ion s

C HAPTER 5

70+25

140+20

G c ' v

60+30 4

(

U) 5± 25 1 40 +45 —40 +25

220 +50 —5 +40

390 +25 —85 +75 225 +35 —5 +20 * 2

z i

1 40 +45

1 15 +50

1 85

5+50

. ,V

2 0°

± 20

yZ

—5 +35

_

4 0°

V

45 +30

1 90+40

g b-65 ±25

60° 885 +45

F igu re 5 . 2 . AR v a lues f o ro cean ic r e g ions o ft h e wo r ld c a lcu la ted b y S tu iver e ta l . ( 1986 :995 ) .

7 2 c o c

2 000

L U C D

1 500 0 3 C C « c r C 3 1000 1 I

I L U

5 00

F I CC « cr

o

I

2 000

1 500

l

l

1 000

A TMOSPHERIC R ADIOCARBON A GE

1

1

1

5 00

0

[ -40 S H ]

( YR B P )

F igure 5 . 3 . Mode l led ma r ine CRAs v s . a tmo sphe r ic CRAs ( Nor ther n H em isphe re ) . T h is c u rve i su sed t oc onver t a n a tmo sphe r ic r ad ioca rbon a ge , i n to a n e qu iva len t mode l led ma r ine r a d ioca rbon a ge ( Qa t )f o r AR c a lcu la t ion ( f rom S tu ive ra nd B raz iuna s 1 993 :154 ) .

4 1

R e se rvo ir C or rec t ions

C HAPTER 5

70+25

1 40+20 60+30 5±2 1 40+45 220±50 -5 +40

390±25 5 ±4 5

2 25+35

1 40+45

1 15+50

2 80±35 2 35±25

1 85 ±20 5+50

1 90+40

1 25±20

40°

60° 885±45

F igu re 5 . 4 . AR v a lues f o ro cean ic r eg ions o ft h e wo r ld ( f rom S t u ive ra nd B raz iuna s 1 993 :156 ) .

N o . o fL abora tor ies R e sponded

L abora tory R e sponse

( n )

C VO

9

1 3 .4

L abo ra to r ies n o t u nder tak ing AR r e sea rch

4 9

7 3 .2

L abo ra to r ies n o t u nder tak ing AR r e sea rch

9

1 3 .4

6 7

1 00

L abo ra to r ies c ur ren t ly u nder tak ing AR r e sea rch

b u t u se t h e S tu ive r e ta l . 1 986 , 1 993 v a lue f o r t h e i r r eg ion T o ta l L abo ra to r ies R esponded T ab le 5 . 3 . C ur ren t AR r e sea rch a round t h ew o r ld .

b ecause o f t h e p auc i ty o f n ew d a ta . T h is i ss e en i n t h e c a l ib ra t ion o f ma r ine s he l l r ad ioca rbon d a tes f r om Ame r ican S amoa ( Hun t a nd K i rch 1 987 ; K irch , H un t a nd T y le r 1 989 ) , t h e Mussau I s lands ( K irch a nd H un t 1 988 ) , a nd Mo loka ' i

REV IE W OFAR RESEARCH S i nce t h e p roposed r e g iona l AR v a lues f o r t h e wo r ld 's o ceans w e re c a lcu la ted b y S tu iver e ta l . i n 1 986 , f ew n ew AR v a lues a ppea red i nt h e 1 993 r ev is ion ( c f . F igure s 5 . 2 a nd 5 . 4 )

I s land , H awa i i (We is le r 1 989 ) . F o r l o ca t ions w he re n o AR v a lue e x is t s , a r chaeo log is t s h ave c a lcu la ted aw e igh ted mean f r om v a lue s f o r i s lands i nt h e ir s t udy v i c in i ty . T h is w a s d one b y K i rch a nd H un t ( 1988 ) a nd K irch , H un t a nd T y le r ( 1989 ) u s ing v a lue s f r om t h e i s lands E n iwe tok , H awa i i a nd t h e

( S tu ive r a nd B raz iuna s 1 993) . O ft h e 2 4 r eg iona l AR v a lue s c a lcu la ted i n 1 986 , o n ly t wo w e re c hanged , a nd t h ree n ew d e term ina t ions a dded i n 1 993 . T he AR v a lue s f r om N ew Z ea land a nd t h e Nor th Amer ican e a s t c oas t a l te red f r om 6 5 ±2 5 t o30 ± 1 5 , a nd 8 5 ±7 5 t o95 ± 4 5 r e spec t ive ly , a nd n ew e s t ima te s c ame f r om S ou th A f r ica ( 125 ± 2 0 ) a nd t h e c oa s t o f P or tuga l ( 235 ± 2 5 a nd 2 80 ± 3 5 ) . R ecen t s t ud ie s

S oc ie ty I s lands t o d eve lop a AR f o r t h e " t rop ica l c en t ra l P ac if ic" . Ic onduc ted

h ave c a lcu la ted AR f o r t h e e a s tern P ac if i c c oa s ta l a nd e s tua r ine w a te r s ( r ang ing b e tween 2 15 ± 3 0 a nd 4 10 ± 4 0 ) ( I ng ram a nd S ou thon 1 996 :575 -576 ) , t h e A egean S ea ( 149 ± 3 0 ) ( Faco re l l is e ta l . 1 998 :969 ) a nd t h e S amoan A rch ipe lago ( 57 ± 2 3) ( Phe lan 1 999 :23) .

a s urvey

o f

1 81

r a d ioca rbon

l a bo ra to r ie s

t h roughou tt h e wo r ld t od e term ine t h e e x ten t o f AR r e sea rch . Ir e ce ived 6 7 r e sponses , a nd o n ly n i ne o f t h e se i n d ica ted i n vo lvemen t i nt h is t ype o fr e sea rch ( Tab le 5 . 3 ; A ppend ix 1 ) . O ft h ese r e sponses , 5i n d ica ted t h a t t h e ir l a bo ra to ry d id n o t d a te m a r ine s h e l l , a nd 4 4 l a bora to r ies n o ted t h a tt h ey s t i l l u se a n Rc or rec t ion . B ecause f ew l a bo ra to r ie s a r e u nde r tak ing

A rchaeo log ica l a pp l ica t ions u t i l is ing AR s i nce 1 986 , o f t en c on t inue t o u se v a lue s s upp l ied b y S tu ive r e t a l . ( 1986 ) ,

t h is r e sea r ch , t h e a pp l icab i l i ty o f AR f o r v a r ious o cean ic

4 2

CHAPTER 5

R ese rvo i r C o r rec t ions

a nd ma r ine f l u sh ing b e tween t h e e s tua r ie s , L ong I s land S ound , a nd t h eo cean ic p romon to ry f o rmed b yC ape C od a nd i t s i s land s ( L i t t le 1 993 :465 ) . T he v a r ia t ions i nr e se rvo i r a ge s c ou ld a l so h ave b een r e la ted t ot h e h ab i ta t s o ft h e d i f f e ren t s he l lf i sh s pec ie s . A s s he l lf ish u se t wo s ou r ce s o fc a rbon f o r s he l l b u i ld ing , D IC a nd m e tabo l ic c a rbon , i tw a s p o s s ib le t h a t t h e s he l lf i sh w i th l a rge R ( t ) v a lue s w e re o b ta in ing ' 4C d ep le ted D IC u pwe l led f r om A n ta rc t ica I n te rmed ia te Wa te r . T h is w a te r c on ta ins ap r e -bomb a nd p r e indu s t r ia l Ro f 7 60 y ea r s , t h e ref o re r a is ing t h e R ( t ) v a lue s s i gn if ican t ly ( L i t t le 1 993 : 4 68 ) .

r eg ions , a nd p rob lems a s soc ia ted w i th i t s c a lcu la t ion , h ave n o t b een w ide ly i n ve s t iga ted . T he l i t e ra tu re r e la t ing t os uch r e sea rch i s t h e ref o re l i m i ted a t p r e sen t . A r e v iew o f p a r t icu la r s t ud ies r ega rd ing t h e c a lcu la t ion a nd u se o f AR s i nce 1 986 i st h e refo re r e qu i r ed t od e te rm ine i t s m e r i t s a nd s ho r t c om ing s f o r c a l ib ra t ing m a r ine s h e l l r a d ioca rbon a ge s f r om N ew Z ea land a r chaeo log ica l s i te s . A Rev iew o f AR Research L i tera ture N ew Z ea land a ppea r s t o l e ad i nr e sea r ch o n AR . T he f i r s t s t udy w a s b y McFadgen a nd Mann ing ( 1990 ) , f o l lowed b y H igham ( 1993) a nd t h en H igham a nd H ogg ( 1995 ) . O the r s t ud ie s o fn o te h ave b een c onduc ted b y L i t t le ( 1993 ) f o r t h e n o r th e a s t c oa s t o f Ame r ica , D ye ( 1994 ) f o r H awa i i , a nd H e ie r -N ie l sen ( 1995 ) f o rt h e D an i sh c oa s t . T he se s t ud ie s a r e s umma r ised b e low .

L i t t le a l so s ugge s ted t h a t t h e s he l lf i sh c ou ld h ave o b ta ined m e tabo l ic c a rbon f r om s ou r ce s s uch a s mode rn o r a nc ien t m a r ine a nd t e r r e s t r ia l p l an td e t r i tu s , i n c lud ing p ea t o rh umus , i n t roduced i n to e s tua r ie s b y r i ve r s ( L i t t le 1 993 :468 ) . I nt h i s s c ena r io , " D i s so lved , p a r t icu la te o r m e tabo l ised o rgan ic c a rbon f r om t e r r e s t r ia l s ou r ce s w i th l ow Al 3C ( ca . 26% 0 ) ,

McFadgen a nd Mann ing ( 1990 ) I n

1 990 ,

McFadgen

a nd

Mann ing

c an r educe s h e l l ADC s ub s tan t ia l ly a nd r a i se R a s h i gh a s 2300 y r s ( Ke i th & A nde r son , 1 963 ; S p ike r , 1 980 ) , o r l owe r ing i t ,d epend ing u pon t h e a ge o f t h e p l an t c a rbon" ( L i t t le 1 993 :468 ) . W i th t h e se p o s s ib i l i t ie s i n m ind , L i t t le ( 1993 :469 ) b e l ieved , " A f l uv ia l s ou rce f o r t h e h i gh AR 's [ f rom t h e H ud son a nd Me r r imack R ive r s , a nd L ong I s land S ound ] i ss uppo r ted b ya n a na ly s i so ft h er e se rvo i ra ge . . ." .

( 1990 :229 -232 )

r e ca lcu la ted t h e 1 986 AR c o r r ec t ion f o r N ew Z ea land u s ing 1 r ad ioca rbon a ges o n m a r ine s he l l o fk nown h i s to r ic a ge . T he AR v a lues w e re s t a t is t ica l ly i n d i s t ingu ishab le a nd r anged f r om 100 t o +4 0 y ea r s . F rom t h ese i n d iv idua l v a lues , aw e igh ted mean AR c o r rec t ion w a s d e r ived f o rN ew Z ea land o f 30 ± 1 3 ( McFadgen a nd Mann ing 1 990 :229 2 30 ) . I t w a s s ugge s ted b y McFadgen a nd Mann ing ( 1990 :230 ) t h a t when c a l ib ra t ing o l d m a r ine s he l l CRAs f o r N ew Z ea land p reh is to ry u s ing t h e S t u ive r e t a l . ( 1986 ) mode l led m a r ine c urve , t h e o l d m a r ine s he l l a ge s hou ld b e c onver ted b ack t o ac onven t iona l r a d ioca rbon a ge b y a dd ing o n t h e N ew Z ea land MSS o f 36 y ea r s . T hen , u s ing t h e CAL IB c ompu te r p rog ram , t h e se d a te s c ou ld t h en b e

L i t t le ( 1993 :465 , 4 70 ) r e commended u s e o f S t u ive r e ta l .' s ( 1986 ) mode l led ma r ine c ur ve f o r t h e c a l ib ra t ion o fm a r ine s he l l CRA , a st h i s m e thod w a s mo re a c cu ra te t h an u s ing a f i xed R c o r r ec t ion a nd a tmo sphe r ic c a l ib ra t ion c urve . F rom h e r a na ly s i s , s h e c a lcu la ted aAR v a lue o f9 5 ±4 3 ' 4C y rf o r t h e No r th E a s t C oa s t o f Ame r ica . L i t t le ( 1993 :470 ) s ugges ted t h a t c hange s i n AR o ve r t ime s hou ld b e i n ve s t iga ted , w hen u s ing p r eh is to r ic t e r r e s t r ia l /ma r ine s he l l p a i r s , a nd t h a tf o ra ccu ra te c a l ib ra t ion o fm a r ine s amp le s , t h e t empo ra l a nd g eog raph ica l c ha ra c te r i s t ic s o f r e servo i r a ge s s hou ld b e d e sc r ibed . S he a l so p ropo sed t h a t f r om v a r ia t ion s i n AR i n h e r s t udy l o ca t ions , o l d t e r re s t r ia l c a rbon f r om h umus o r p ea t b rough t i n to e s tua r ie s b y r i ve r s w a s t h e p robab ly t h e m a in s ou r ce o ft h e s i gn if i can t d i sc repanc ie s i n r e se rvo i r a ge s i nt h e r eg ion ( L i t t le 1 993 :470 ) . T he i n pu t o f A n ta rc t ic I n te rmed ia te Wa te r s , moder n p l an t d e t r i tu s , a nd d i s so lved l i me s tone w e r e b e l ieved t o b e o f s e conda ry i mpo r tance .

c a l ib ra t ed u s ing t he N ew Z ea land AR c o r rec t ion o f3 0 ±1 3 y ea r s . L i t t le ( 1993 ) L i t t le ( 1993 ) u sed 1 5 p a i red c ha rcoa l a nd ma r ine s he l l a r chaeo log ica l s amp le s , a nd 1 0 m a r ine s he l l s amp le s p a ired w i th w ood o fk nown h i s to r ic a ge , t oi n ve s t iga te t h e r e servo i r e f f ec t a nd l o ca l AR c o r r ec t ion a l ong t h e n o r th e a s t c oa s t o f Ame r ica . S i x teen l o ca t ions w e re s amp led f r om f i ve s t udy a r ea s . T he r e se rvo ir a ge R ( t ) f o re ach t e r r e s t r ia l /ma r ine s he l l p a i rf r om h e r 1 6 s amp led l o ca t ion s ,w a s f o und b ys ub t rac t ing t h e c onven t iona l t e r re s t r ia l ' 4C a ge f r om i t s p a i red c onven t iona l m a r ine s he l l ' 4C a ge . L i t t le ( 1993) d e te rm ined AR f o r e a ch l o ca t ion u s ing m e thod o ne a s o u t l ined a bove , a nd a s s igned am ean AR f o re a ch o ft h ef i ve s t udy a r ea s .

H igham ( 1993 ) H igham ( 1993 )t e s ted McFadgen a nd Mann ing 's ( 1990 )N ew Z ea land AR v a lue u s ing p a i red c ha r coa l a nd m a r ine s he l l r a d ioca rbon d a te s f r om t h e a r chaeo log ica l s i te s S hag Mou th a nd P l ea san t R ive r i n O tago , a nd f r om t h e Awa roa I n le t a r chaeo log ica l s i t en ea rN e lson .

L i t t le f ound c l o se a g reemen tb e tween t h e c a l ib ra ted c ha rcoa l a nd m a r ine s he l l d a te s f o r b o th p r eh i s to r ic a nd h i s to r ic s amp le s , w hen u s ing t h e m ean AR v a lue f r om e ach s t udy

H igham ( 1993 :125 ) c a lcu la ted AR u s ing t h e S tu ive r a nd B raz iuna s ( 1 993 ) t e r re s t r ia l /ma r ine s h e l l p a i r m e thod ( s ee a bove a nd F i gu re 5 . 3 ) . F o r e ach s i t e , h e p oo led t h e s t a t is t ica l ly i n d i s t ingu i shab le c ha r coa l r a d ioca rbon d a te s , a nd c onve r ted t h i s p oo led m ean a ge i n to am ode l led m a r ine a ge . H e t h en c ompa red t h i s m ode l led m a r ine a ge w i th e ach m a r ine s he l l CRA . A t t h e S hag Mou th s i te , 1 3 c ha r coa l r a d ioca rbon d a te s w e re p oo led a nd t h en c ompa red t oe ach o f t h e 1 5 ma r ine s h e l l r ad ioca rbon a ge s . H igham 's ( 1993 :152 )

a r ea . S he d i d ,h oweve r , d e t ec ta noma lou sR ( t ) a nd AR v a lue s f r om s ome o fh e r s amp led l o ca t ion s , a nd d i scus sed w he the r t h e v a r ia t ions i n AR w e re e i the r t h e r e su l t o f g eog raph ic i nf luence s ,o rt empo ra lv a r iab i l i ty . T h ree l o ca t ions w i th p a r t icu la r ly v a r iab le R ( t )a nd AR v a lues w e re L ong I s land S ound , a nd t h e H ud son a nd Me r r imack R ive r s . S amp led s i tes a r ound L ong I s land S ound , a nd n ea r t h e r i ve r m ou ths , h ad h i ghe r AR t h an i nt h e G u lf o f Ma ine . L i t t le p ropo sed t ha tg eog raph ic i n f luence s m ay h ave a f f ec ted t h e m a r ine s he l l a ges d ue t of l uv ia l i n pu t a tt h e se l o ca t ions ,

c a lcu la t ion s d e r ived a AR v a lue o f 1 6 f o r t h e s i te w i th a w e igh ted m ean s i gma ± 1 , a nd a s c a t te r m ean s i gma o f±

4 3

R ese rvo ir C o r rec t ions

CHAPTER 5

b e tween s e ven o ft h e p a i red c ha rcoa l a nd m a r ine s he l l CRAs f r om t h e s i t e s . T h is i nt u rn l e d t o l a rge d i screpanc ie s i n AR v a lue s b e tween s i te s . A l though n o e xp lana t ions w e re p ropo sed f o r t h e a ge d i f f e rence s o b se rved a t s i te H 8 i n H awa i i ( o the r t h an p o s s ib le p rob lem s w i th t h e r a d ioca rbon d a te s o n w ood c ha rcoa l f o r t wo p a i r s ) , D ye ( 1994 :52 ) d i d e xp re s s h i s c oncerns r e ga rd ing t h e p rovenance o f t h e s amp le s , a nd t h e s he l lf i sh s pec ie s w e r e u nknown . D ye d i d n o t s pec if y p o s s ib le r e a son s f o r t h e e x t r eme a ge d i f f e rence s b e tween t h ec ha rcoa l a nd m a r ine s he l l p a i r s f r om t h e B a rbe r s

3 3 . F o l low ing S t u ive r e ta l . 's ( 1986 ) r e commenda t ion t h a t t h e l a rges t 1s t anda rd e r ro r s hou ld b e u s ed o ft h e w e igh ted a nd u nwe igh ted ( " sca t te r " ) m eans , H igham f ound t h a t h i s AR v a lue o f 1 6 ±3 3 w a s s t a t is t ica l ly i n d i s t ingu i shab le f r om McFadgen a nd Mann ing 's ( 1990 ) A R v a lue o f 3 0 ± 1 3 ( H igham 1 993 :128 129 ) . A t t h e P l ea san t R ive r s i t e , AR v a lue s v a r ied g r ea t ly b ecause o f l a rge a ge d i sc r epanc ie s b e tween d i f f e r en t s he l lf i sh s pec ie s . I n i t ia l ly H igham ( 1993 :152 ) b e l ieved t h a t t h e a ge d i f f e rence s w e re p o s s ib ly d ue t o s p ec ie s h ab i ta t a nd e nv i ronmen ta l i nf luence s . L a te r a na ly s is o f t h e s i t e f ound t h a t as and d epo s i t , w h ich o nce s epa ra t ed t wo c u l tu ra l l a ye r s , h ad g radua l ly b een e r oded o ve r t ime b y t i da l a c t ion . T h is p roce s s t h e ref o r e m ixed c u l tura l m a te r ia l f r om t wo p a s t a nd u n re la ted e ven t s ( H igham p e r s . c omm . ) . A tt h e Awa roa I n le t s i te , s amp le p rovenance a nd p os t -depo s i t iona l h i s to ry , w e re

P o in t s i te s , o rt h e l a rge AR d i f f e rence b e tween t h is s i te a nd s i te H 8 , b u t h e d i d n o te t h a t B a rbe r s P o in t i sl o ca ted o n t h e ' Ewa C o ra l P l a in ( Dye 1 994 :54 ) . D ye ( 1994 :55 ) e xam ined t h e e f f ec t o fd a t ing m a r ine s h e l l s f r om t wo d i f f e ren t c oa s ta l g eo log ica l e nv ironmen t s , o ne c ons i s t ing o f P l e is tocene l i me s tone , t h e o t he r f o rmed f r om H o locene l a va , u s ing s he l lf i sh s pec ie s c ommon ly f ound i n H awa i ian a r chaeo log ica l s i te s . T he m a r ine s he l ls s e lec ted f o r d a t ing o r ig ina ted f r om l o ca t ion s w i th s im i la r g eo logy a s f o und a ts i t e H 8 ( Ho locene l a va ) a nd t h e B a rbe r s P o in t s i t e s ( P le i s tocene l i me s tone ) . Ma r ine s h e l l f r om t h e l i me s tone

s e cu re ( a s a tS hag Mou th ) . A AR v a lue o f 5 5 ±3 9 w a s d e r ived f r om t h is s i te u s ing t wo c ha r coa l a nd t wo m a r ine s he l l r ad ioca rbon d a te s . T h is AR v a lue w a s a l so s t a t is t ica l ly i n d is t ingu i shab le f r om t h e McFadgen a nd Mann ing ( 1990 ) c or rec t ion .

e nv i ronmen t s howed g r ea t ' 4C a ge s a nd h ighe r AR v a lue s t h an t h e s ame s pec ie s d a ted f r om t h e v o lcan ic e nv i ronmen t ( Tab le 5 . 4 ) .

D ye ( 1994 ) D ye ( 1994 ) i n ve s t iga ted AR f o r v a r iou s c oa s ta l a r ea s i n H awa i i , u s ing b o th m a r ine s he l ls o fk nown h i s to r ic a ge , a nd c ha rcoa l /ma r ine s he l l p a i r s . T h is s t udy a l so e xam ined t h e e f f ec t o f c oa s ta l v o lcan ic a nd l i me s tone g eo logy o n t h e r ad ioca rbon d a t ing o fs he l lf i sh s pec ie s .

T he a ge s d i f f e rences f r om t h e s h e l l s d a ted f r om t h e l i me s tone c oa s t w e re e xp la ined a s b e ing d ue t ot wo f a c to r s : I )t h e e nv i ronmen t i nw h ich t h e s he l lf i sh d eve loped , a nd 2 ) t h e f e ed ing h ab i t s o f p a r t icu la r s h e l lf i sh s pec ie s . D ye s ugge s ted t h e o lde r a ge s may h ave r e su l ted f r om t h e P l e is tocene l i me s tone b e ing a s ou r ce o f o ld c a rbon , w h ich w a s i n ge s ted b y t h e g a s t ropods e i the r f r om t h e a l gae f e d u pon , o r d i r ec t ly f r om t h e l ime s tone t h ey s c raped w h i le f e ed ing ( Dye 1 994 :55 ) . D ye ( 1994 :55 -56 ) b e l ieved t h a t t h e a ge o ft h e g a s t ropod s amp le B e ta -54331 b e ing y ounge rt h an t h e o t he r t wo g a s t ropod s amp le s ( Be ta -54332 , B e ta -54333 ) f r om t h e i n te r t ida l a nd s p la sh -zone l i me s tone a r ea , m ay b e d ue t o i t s s ha l low o f f sho r e h ab i ta t , o r d i f f e rence i n d i e t ( wh ich a l so i n c luded H o locene r e ef a nd r e ef d e t r i tu s ) . F ac to r s o t he rt h an g eo logy i d en t if ied a sp o s s ib ly i nf luenc ing t h e d a te s o n s he l l f r om t h e v o lcan ic c oa s t l ine s , w e re u pwe l l ing a nd r i ve r ine c a rbon . D if f e r ences i nc a rbon u p take b e tween s h e l lf i sh s pec ie s w a s a l so s e en a s a p o s s ib le i nf luence o n t h e r ad ioca rbon a ge o f m a r ine s he l ls f r om H awa i i .

D ye o b served t h a t AR c a lcu la ted f r om t h e e i gh tm a r ine s he l ls o f k nown h i s to r ic a ge , s howed s i gn if ican t v a r ia t ion . A l though t h e s he l ls d a ted w e re c o l lec t ed b e tween 1 9 18 a nd 1 947 , t h e A R v a lue s r a nged f r om 500 t o 3 820 y ea r s . H e s ugges ted t h e l a rge AR v a lue o f 3 820 y ea r s f r om P ea r l H a rbou r w a s p o s s ib ly d ue t o p o l lu t ion o f t h e h a rbou r b y f o s s i l f u e ls d u r ing U .S . n ava l o ccupa t ion ( Dye 1 994 :51) . F o r t h e r ema in ing s even AR v a lue s , D ye ( 1994 :52 ) n o ted , " No h ypo the se s h ave b een a dvanced t o a c coun t f o r t h e e x t reme v a r iab i l i ty i nt h ea ppa ren ta ges o ft h e se s h e l ls ." . D ye ( 1994 :52 -54 ) t h en c ompa r ed 1 p a i red c ha r coa l a nd m a r ine s he l l r a d ioca rbon a ges f r om t h e a r chaeo log ica l s i te H 8 a t Wa i 'ahuk in i i n H awa i i , a nd f r om s i te s a t B a rbe r s P o in t , O 'ahu . H e o b se rved s i gn if i can t a ge d i f f e rence s

L ab n o .

S pec ie s

S ub s tra te

C o l in . y r

C onven t . a ge

B e ta -54332

C .e xa ra ta

L ime s tone

1 9 14

1 270 ± 8 0

B e ta -54336

C . e xa ra ta

V o lcan ic

1 923

7 40 ±2 70

2 70

B e ta -54331

C .capu t se rpen t s

L ime s tone

1 9 15

9 80 ± 8 0

5 10

B e ta -54334

C .capu t se rpen t s

V o lcan ic

1 923

7 30 ± 8 0

2 60

B e ta -54333

N .p icea

1 930

1 230 ± 8 0

7 60

B e ta -54335

N .p icea

L ime s tone _ V o lcan ic

1 924

'6 10 ± 8 0

1 40

"C

AR v a lue 8 00

T ab le 5 . 4 . " AMS D a te so n Ma r ine S he l ls f r om P l e i s tocene L ime s tone a nd H o locene V o lcan ic C oa s t ." ( f rom D ye 1 994 :55 ) .

4 4

CHAPTER 5

R e se rvo ir C o r rec t ions

D ye ( 1994 :56 ) c onc luded t h a t v a r ia t ion i nd a te s o n m a r ine s h e l l f r om H awa i i c ou ld p o s s ib ly i n t roduce u nce r ta in ty i n c a l ib ra t ing s amp les f r om a r chaeo log ica l s i te s , b u t i d en t if ica t ion o ff a c to r s w h ich i n f luence t h e d a t ing o fs h e l l s

i d en t if y t h e AR v a lue a nd c a l ib ra t ion c u rve u sed ( H igham a nd H ogg 1 995 : 4 15 ) . H e ier -N ie l sen e ta L ( 1995 )

c ou ld a i d i nr e duc ing e r ro r s i n AR v a lue s . H e b e l ieved t h a t d i f f e ren t A R v a lues f o r l i me s tone a nd v o lcan ic c oa s ta l r e g ions , a nd f o rs pec if ic s h e l lf i sh s pec ie s , s hou ld b e u sef u l i n p a r t icu la ra r cha eo log ica l s i tua t ions ( Dye 1 994 :56 ) .

H e ie r -N ie lsen e ta l . ( 1995 ) m ea su red 2 8 AMS ' 4C d a te s f r om m o l luscs c o l lec ted l i ve b e tween 1 885 AD a nd 1 945 AD f r om D an ish w a te r s . F our teen o f t h e se s amp les c ame f r om t h e D an i sh c oa s t a tS kage r rak -Ka t tega t a nd f r om t h e B e l t s , w i th t h e o t he r 1 4 c om ing f r om D an i sh f j o rd s . F rom t h e se m ea su remen t s , r e se rvo i ra ge s ( R ( t ) ) , a nd AR w e re c a lcu la t ed

H igham a nd H ogg ( 1995 )

f o r t h e v a r ious l o ca t ion s . I tw a s f ound t h a t t h e AR v a lue f o r c oa s ta l D enma rk w a s 1 3 ±1 6 y r s ( h av ing as c a t te r s t anda rd e r ro r o f ±2 1 y r s ) , w h ich w a s c on s is ten t w i th a n e a r l ie r c a lcu la t ion o f 33 ± 2 7 y r s f o r t h e Norweg ian -Swed i sh

H igham a nd H ogg ( 1995 ) d e te rm ined a n ew AR v a lue f o r N ew Z ea land u s ing t h e M cFadgen a nd Mann ing ( 1990 ) h i s to r ic s he l l d a ta , f i sh o t o l i th s o f k nown h i s to r ic a ge f r om K a l i sh ( 1993 ) ,a nd t he S hag Mou th a r chaeo log ica ls i te p a i red c ha r coa l a nd m a r ine s he l l r a d ioca rbon d a tes . T h i s p ape r i s p a r t icu la r ly s i gn if ican t f o r w o r ld AR r e sea rch , b ecau se n o t o n ly a r e b o th m e thodo log ie s e mp loyed t o d e te rm ine t h i s l o ca l r e se rvo i r c or rec t ion , b u t i t i s t h e o n ly p ub l i shed r e sea rch w he re a l l s amp le t y pe f a c to r s h ave b een f u l ly a dd r e s sed . T he h i s to r ica l ly c o l lec ted s amp le s h ad c a r ef u l p r ovenance a nd t h e p reh i s to r ic c ha rcoa l u sed f o r c a lcu la t ing A R h ad b een i d en t if ied t ot w ig s o fs ho r t l ived t r ee a nd s h rub s p ec ies .

S kager rak -Ka t tega tc oa s t s . T he se r e su l t sa l so a g reed w i th AR v a lues f r om t h e Nor th A t lan t ic a nd t h e N o r th S ea o f0 ,a nd t h e U n i ted K ingdom o f 1± 8 .H oweve r , t h e r ema in ing 1 4 s he l l a ges f r om t h e D an i sh f j o rd s g ave c ons i s ten t ly h igh R ( t ) a nd AR v a lue s . I tw a s f o und t h a t f r e sh w a te r r u n -of f a nd g round w a te r f l ow inm i n to t h e f i o rd s c on ta ined d i s so lved s o i l c a rbona te l ow i n C , t h e r ef o re i n c rea s ing t h e a ppa ren t s he l lf i sh a ge . I tw a s c onc luded b y H ie r -N ie l sen e ta l . ( 1995 ) , t h a t a l though t h e D an i sh , N o rweg ian a nd S wed i sh c oa s t s w e re p a r t o f au n if o rm ' 4C r e se rvo i r , t h e f i o rd s w e re n o t u n if o rm b ecause o ft h e i nf lux o ff r e sh w a te r .

T he K a l ish ( 1 993) s nappe r ( Pag ru s a ura tu s ) o t o l i th s w e r e c o l lec ted b e tween 1 918 a nd 1 955 f r om t h e e a s t c oa s t o ft h e N o r th I s land , a nd w e re o r ig ina l ly u sed b y t h e r e sea r che r t o i n ve s t iga te p r e - a nd p o s t -bomb r ad ioca rbon a c t iv i ty i nt h e s ou thern t empe ra te o cean . H igham a nd H ogg ( 1995 )

D ISCUSS ION AND CONCLUS IONS

c a lcu la ted A Rv a lues f r om t h e s even AMS a ge s t a ken o n t h e o t o l i ths , a nd f r om McFadgen a nd Mann ing 's ( 1990 ) e a r l ie r h i s to r ic s he l l d a ta . T he K a l i sh ( 1993) A R v a lue s w e re f o und t o b e s t a t i s t ica l ly i nd i s t ingu i shab le f r om McFadgen a nd Mann ing 's ( 1 990 ) AR v a lue o f 30 ± 1 3 , p roduc ing a n o ve ra l l e r ro r -we igh ted m ean A R c o r rec t ion o f2 5 ±1 5 1 4c . y ea r s( H igham a nd Hogg 1 995 :4 11) . P a i r ed c ha r coa l /ma r ine s h e l l d a tes f r om S hag Mou th ( s ee a bove ) , w e r et h en u sed t ot e s t t h i s v a lue ( H igham a nd H ogg 1 995 :4 11-4 15 ) . T he r ev i sed c a lcu la ted AR f o r t h i s s i te i s1 3 ±1 7 ( due t ot h e a dd i t ion o f f o u r s he l l a ge s ) ( H igham a nd H ogg 1 995 :4 15 ) . T h is v a lue w a s o b se rved a s s t a t i s t ica l ly i n d i s t ingu i shab le f r om t h e H igham a nd H ogg ( 1995 ) AR e s t ima te o f 2 5 ± 1 5 , b u t s t a t is t ica l ly d i f f e ren t f r om t h e M cFadgen a nd Mann ing ( 1 990 ) AR o f3 0 ±1 3 . H igham a nd H ogg ( 1995 ) t h en u t i l i sed t h e 2 5 ±1 5 AR t o c a l ib ra te t h e p oo led m ean m a r ine s h e l l CRA s f r om S hag Mou th , f o r c ompa r ison w i th t h e p oo led m ean c a l ib ra ted c ha rcoa l d a te . T he c a l ib ra ted ma r ine a nd c ha rcoa l r a d ioca rbon d a te s m a tched c omf o r tab ly ( H igham a nd H ogg 1 995 :4 15 ) . H igham a nd H ogg ( 1995 :4 15 ) c onc luded t h a t t h e n ew AR v a lue w ou ld a c cura te ly c a l ib ra te m a r ine s he l l r a d ioca rbon a ge s f r om S hag Mou th , a nd t h a t t h e r e g iona l o cean a ppea r s t oh ave b een s t ab le i nt h e r e cen t p a s t . T hey b e l ieved t h a t a k now ledge o f t he l o ca l e nv i ronmen t f r om w h ich t e r r e s t r ia l /ma r ine s he l l p a i r s a r e d e r ived w a s v i ta l i n c a lcu la t ing A R , t oa ccoun t f o r f a c to r s s u ch a st h e h a rd w a te r e f f ec t . A l so , t h e i d en t if ica t ion o f c ha rcoa l t o t w ig s f r om s ho r t l ived f l o ra s pec ie s p r io rt od a t ing w a s c r i t ica l . H igham

E a r ly o b serva t ions b y r a d ioca rbon l a bo ra to r ie s o n d i f f e rence s i nr ad ioca rbon a ge b e tween t e r re s t r ia l a nd ma r ine s amp le s , l e d t o t h e d eve lopmen t o f c oun t ry s pec if ic R e se rvo i r C o r rec t ions ( R , R * ) o r Ma r ine S he l l S t anda rds ( MSS ) . T hese c o r rec t ion s w e re a pp l ied t o m a r ine s he l l r a d ioca rbon a ge s f o r c onve r s ion t ot e r re s t r ia l d a te s , s o t h ey c ou ld b e c a l ib ra ted u s ing a tmo sphe r ic c a l ib ra t ion c urve s , w he re t h e r e la t ionsh ip b e tween r a d ioca rbon a ge s a nd c a lenda r y ea r s w a s k nown . T h is m e thod f o r c a l ib ra t ing m a r ine s he l l CRAs i ss t i l l t h e mo s t c ommon m e thod u sed b y r a d ioca rbon l a b s a nd r e sea rche r s t oday . T he R v a lue s u sed a r e b a sed o n a n a ve rage o f R ( t ) c a lcu la t ions , w h ich r ef lec t v a r ia t ions i na ppa ren t a ge b e tween m a r ine s he l l r a d ioca rbon d a te s a nd k nown y ea r o fc o l lec t ion o ft h e s amp le s , o rp a i red t e r re s t r ia l ' 4C d a te s . Rv a lue s h ave p rog re s s ive ly c hanged i n s ome c oun t r ie s ( s uch a sN ew Z ea land ) , a s mo re R ( t ) d a ta h a s b een c o l lec ted . T h i s h a s b rough t a bou t c onf us ion f o r a r chaeo log is t s w hen c ompa r ing ma r ine s he l l r a d ioca rbon a ge s f r om s i tes w h ich h ave b een d a ted o ve r an umbe r o f y ea r s . S t u ive r e t a l . ( 1986 ) r e cogn i sed t h e t empo ra l ly f l uc tua t ing e nv i ronmen t o f t h e m ixed l a ye r o cean , a nd d eve loped a mode l led ma r ine c a l ib ra t ion c urve b a sed o n aG loba l C a rbon Mode l . T h is c a l ib ra t ion c u rve p rov ided a s t anda rd m e thod b a sed o n o cean ' 4C r e se rvo i r p a rame te r s b y w h ich ma r ine s he l l CRAs c ou ld b e c a l ib ra ted , a nd a vo ided t h e u se o ft h e a tmo sphe r ic c urve , w h ich t h e r e se rvo i r c or rec t ion me thod r e qu i red . T he mode l led m a r ine c u rve c on s ide red s ho r t te rm f l uc tua t ions o f ' 4C i n t h e m ixed l a ye r o cean , t h e r eby c o r rec t ing t h e d ef ic ienc ie s o f u s ing a f i xed R o r MSS . S t u ive r e t a l . ( 1986 ) a l so i n t roduced a r eg iona l ma r ine r e se rvo i r c o r rec t ion , t e rmed AR , w h ich t ook i n to a ccoun t r e g iona l o cean ma r ine r e se rvo i r d i f f e rence s , a nd w h ich w a s t ime i n dependen t .

a nd H ogg ( 1 995 :415) n o ted t h a t a sN ew Z ea land 's AR v a lue m ay c hange , i tw a s t he r e spon s ib i l i ty o ft h e r e sea rche r w ho h a s o b ta ined t h e ma r ine s h e l l d a tes t op ub l ish t h e CRA s , a nd

4 5

R e se rvo i rC o r rec t ions

CHAPTER 5

H oweve r , p rob lems h ave a r isen i nt h e a pp l ica t ion o fS t u ive r e ta l . 's ( 1986 , 1 993) n ew m a r ine s he l l c a l ib ra t ion m e thod . T he se mus t b e a dd res sed i f w e a r e t o e va lua te i t s a pp l icab i l i ty f o r c a l ib ra t ing m a r ine s he l l r a d ioca rbon a ge s f r om N ew Z ea land a r chaeo log ica l s i te s .

Mann ing ( 1 990 :231) AR v a lue o f3 0 ±1 3 Ly ea r s f o rN ew Z ea land w a s c or rec t , t h e l a rge s t s i gma w a s i n co r rec t ly r epor ted a s ± 4 1 ' 4C y ea r s , c a u s ing c onf u s ion f o r s ome a r chaeo log i s t s a s t o w h ich s i gma s hou ld b e u s ed . O f t h e s t ud ies r e v iewed , o n ly H igham ( 1 993 ) , H igham a nd H ogg ( 1995 ) , a nd H e i r -N ie l sen e ta l . ( 1 995 ) , s t r ic t ly f o l lowed t h e m e thod o fS t u ive re ta l . ( 1986 , 1 993 ) . T he se s t ud ie s i l us t ra te t h e n eed f o r mo re r e g iona l AR m ea su remen t s . 1 4 -

T he se p rob lems s t em f r om t h ree o b se rva t ions . F i r s t ly , t h e n umbe r o f m a r ine s he l l s amp le s f r om e ach o cean ic r e g ion u sed i n t h e 1 986 AR c a lcu la t ions w a s s ma l l , a nd f ew a dd i t ions t o t h e o r ig ina l c a lcu la t ions h ave b een m ade s i nce t h is t ime . S econd ly , p rob lems w h ich c an a f f ec t t h e c a lcu la t ion o f l o ca l AR , h igh l igh ted i n s ub sequen t s t ud ie s , w e re n o t c ons ide r ed f o r t h e s amp le s u sed i nd e te rm in ing t h e 1 986 v a lue s . T h i rd ly , t h e m e thodo log ie s e mp loyed f o r d e r iv ing AR f o r v a r iou s r eg ions b y r e sea r che r s s i nce 1 986 h ave b een i n con s i s ten t . T ab le 1s upp l ied b y S tu ive r e ta l . ( 1986 :10 17 102 1) , s hows t h e n umbe r o fm a r ine s he l l s amp le s u sed t od e r ive r e g iona l AR a round t h e w o r ld a ve rage s 5 , w i th a r a nge o f 2t o 9 s amp le s . T he n umbe r o fs amp les w a s t h e ref o re s ma l l , w hen c ompa red t o t h e n umbe r e mp loyed b y McFadgen a nd Mann ing ( 1990 ) , T a lma ( 1990 ) , H igham ( 1993 ) , L i t t le ( 1993 ) , D ye ( 1994 ) , H igham a nd H ogg ( 1995 ) a nd H e ie r N ie lsen e ta l . ( 1995 ) . I tw a s f ound f o r N ew Z ea land , t h a t w i th a n i n c rea se i n t h e n umbe r o f s amp le s e mp loyed t o d e r ive AR , t h e o r ig ina l v a lue c hanged d r ama t ica l ly . T h i s s ame p rob lem w a s e ncoun te red w i th t h e c a lcu la t ion o f t h e N ew Z ea land Ma r ine S he l l S t anda rd . A l so , b ecau se l i t t le u pda t ing o r a dd i t ion t o t h e o r ig ina l 1 986 c a lcu la t ions h a s o ccur red , a r chaeo log i s t s c a l ib ra t ing m a r ine s he l l r a d ioca rbon d a tes f r om v a r iou s s i te s i nP o lynes ia , f o r e xamp le , s t i l l u se t h e 1 986 v a lue s , s ome a ve rag ing s e t s o ft h e se AR c o r rec t ion s f r om a r ea sc l o se t ot h e i r l o ca t ion o fs t udy .

a f f ec t AR . A noma lou s m a r ine s he l l r a d ioca rbon a ge s r e su l t f r om t h e h a rdwa te r e f f ec t , u pwe l l ing , t h e u s e o fe i the r o pen b each o r e s tua r ine s pec ie s , a nd t h e i n take o f m e tabo l ic c a rbon b y p a r t icu la r s he l lf i sh s pec ie s . A s i t i s u nc lea r w he the r t h e se f a c to r s w e re c ons ide red i nt h e c a lcu la t ion o f

AR . E xamp le s i n c lude : n o t i d en t if y ing c ha r coa l ; n o t c ons ide r ing t h e h ab i ta t s a nd l i f eway s o f s he l lf i sh a nd p l an t s pec ie s ; l a ck o fd a ta c oncern ing s amp le p rovenance ; a nd n o t c ons ide r ing t h e p o s t d epo s i t iona l h i s to ry o f t h e s i te b e ing d a ted . A l l t h ese f a c to r s mus t b e c on s ide r ed i fr e sea r che r s a r e t o t e s t t h e r e l iab i l i ty o f v a r iou s m a r ine s he l l s p ec ie s f o r d a t ing p r eh i s to r ic c on tex t s .

S t ud ie s w he r e g eog raph ic o r e nv i ronmen ta l f a c to r s h ave b een p ropo sed t ob e r e spon s ib le f o r a noma lou s AR v a lue s , s hou ld a l so b e c l o se ly s c ru t in i sed a s m e thodo log ica l p rob lems m ay b e t h e r e a son f o r t h e u nusua l v a lue s . F o r

C hap te r s 4a nd 5h ave i d en t if ied t h ep o ten t ia l p rob lem s w hen d a t ing c ha rcoa l a nd ma r ine s h e l l s amp le s f r om a r chaeo log ica l s i te s , a nd w hen c ompa r ing c a l ib ra ted c ha rcoa l a nd m a r ine s he l l CRAs . I n t h e f o l low ing c hap te r , d e sc r ip t ion s o f t h e a r chaeo log ica l s i t e s s amp led f o r t h i s d i sser ta t ion t o d e term ine t h e r e l iab i l i ty o f m a r ine s h e l l f o r r ad ioca rbon d a t ing N ew Z ea land p r eh i s to ry a r ep r e sen ted .

e xamp le , e x t reme v a r ia t ion s i n AR v a lue s o b se rved b y L i t t le ( 1993) a nd D ye ( 1994 ) , p o s s ib ly r e su l ted f r om u s ing o l d w ood i nt h e i r t e r r e s t r ia l /ma r ine s he l l a ge c ompa r i sons . T he w ood u sed a st h e t e r re s t r ia l c ompa r ison i nt h e se s t ud ie s w a s n o t i d en t if ied t ot w ig s o fs ho r t l ived s pec ie s ( c f . H igham a nd H ogg 1 995 ) . I n a dd i t ion t o t h is , t h e h i s to r ic s he l l u sed b y L i t t le ( 1993 ) h ad n o s pec if ic p rovenance d a ta , n o r h ad t h e t e r re s t r ia l /ma r ine s he l l p a i r s f r om D ye 's ( 1994 ) H awa i ian a r chaeo log ica l s i te H 8 . ( 1986 ,

1 993 )

s e t

d own

c ons i s ten t . H oweve r , r e sea rche r s u s ing o r d e r iv ing AR s hou ld b e c a ref u l n o t t o r epea t t h e m i s take s w h ich h ave o ccur red w i th u se o f t h e r e se rvo i r c o r r ec t ion m e thod . I ti s v i ta l t h a t w hen r e sea rche r s p ub l i sh t h e i r r a d ioca rbon d a ta ,

h ave b een c ons is ten t i nt h e me thodo logy u sed t od e r ive AR , r e commended b y S t u ive r e ta l . ( 1 986 , 1 993) . A dd i t iona l ly , e r ro r s m ade i nc a lcu la t ing R , w e r e a l so m ade i nc a lcu la t ing

t h e o r ig ina l AR v a lue s , t h e S tu ive r e ta l . ( 1986 ) A R v a lue s s hou ld b ev i ewed a sf i r s ta pp rox ima t ions o n ly .

S t u ive r e t a l .

I n c onc lu s ion , t h e i n t roduc t ion o f a mode l led m a r ine c a l ib ra t ion c urve h a s g r ea t ly s imp l if ied t h e e a r l ie rd i ff icu l t ie s e xpe r ienced b y r e sea rche r s w hen c a l ib r a t ing t h e i r r ad ioca rbon d a te s u s ing c hang ing R c o r r ec t ion s o r m a r ine s he l l s t anda rd s . I t h a s a l so m ean t t h a t t h e m e thod f o r c a l ib ra t ing m a r ine s he l l r ad ioca rbon d a te s s hou ld b e g l oba l ly

t h ey p rov ide t h e CRAs , i n form t h e r e ade r w h ich AR v a lue t h ey e mp loy , a nd t h e c a l ib ra t ion c u rve s u t i l ised ( s ee H igham a nd H ogg 1 995 :4 15 ) . T h is r ev iew h a s f o und t h a t f ew s t ud ie s

G eog raph ic a nd e nv i ronmen ta l p rob lems h ave b een s hown t o

A l though

A n a dd i t iona l p rob lem i st h e i n con s i s ten t a dv ice g i ven t o a r chaeo log i s t s o n h ow t oc a l ib ra te t h e i r m a r ine s h e l l CRAs . A n e xamp le o f t h is i s McFadgen a nd Mann ing 's ( 1990 ) r e commenda t ions t o a r chaeo log i s t s w hen u s ing S t u ive r e t a l .' s ( 1986 , 1 993 ) mode l led m a r ine c a l ib ra t ion c urve . T hey s ugge s ted t h a t r e sea rche r s s hou ld a dd t h e NZMSS o f 36 y ea r s t o t h e i r o l d r e se rvo ir c o r r ec ted m a r ine s h e l l d a te s t o c onver t t h e se b ack i n to a c onven t iona l r a d ioca rbon a ge . H oweve r , a st h e m a r ine s he l l s t anda rd h a s v a r ied b y 5 9 y ea r s s i nce 1 972 , t h e a pp l ica t ion o f3 36 y ea r s c anno t b e a pp l ied t o a l l o ld r e se rvo i r c or rec ted ma r ine s h e l l r ad ioca rbon d a te s . T h is w ou ld n o t o n ly p roduce a s e r ie s o f f a l se CRAs , b u t wou ld a l so p rov ide i n accu ra te c a l ib r a t ions o n t h e n ew mode l led m a r ine c a l ib ra t ion c urve .

c l ea r

g u ide l ine s f o r c a lcu la t ing a nd r e por t ing AR , s ome r e sea rche r s h ave n o t f o l lowed t h e se r e commenda t ions . S ome t ime s i n co r rec t c a lcu la t ions h ave b een u sed , a nd a t o t he r t ime s t h e r e po r ted v a lues a r e t oo p r ec i se ( s ee H igham 1 993 :128 129 ) . F o r e xamp le , t hough t h e McFadgen a nd

4 6

CHAPTER 6 ARCHAEOLOG ICAL EXCAVAT IONS " F i r s t , i tw a sc l ea rt om et ha tt h en ex ta d vance i no u rk now ledge o fh uman a ch ievemen to u t s id et h eh i s to r ica lf i e ld w a s d epend en tu pon f re sh a nd m e thod ica ld i scove ry , a nd t ha tf re sh d i scovery i ng rea tm ea sure m ean tf re sh d igg ing ." S i r Mo r t ime r W hee ler ( 1955 :54 ) .

I NTRODUCT ION T h i s c hap te r d e sc r ibe s t h e 1 a r chaeo log ica l s i te s e xcava ted a nd s amp led f o rt h is s t udy . T he a im o ft h e se e xcava t ion sw a s t oo b ta in c ha rcoa l /ma r ine s he l l p a i r st oi n ve s t iga te t h e u se o f m a r ine s h e l l f o rr ad ioca rbon d a t ing N ew Z ea land p reh i s to ry . T he se s i te s w e re s e lec ted t o a nswe r p a r t icu la r q ue s t ions r e ga rd ing t h e d a t ing o f ma r ine s he l l f r om v a r ious r eg ion s o f t h ec oun t ry . T he K okohu ia a r chaeo log ica l s i te w a s s e lec ted t oi n ve s t iga te t h e p o s s ib le i nf luence s o ft h e h a rd w a te r e f f ec t o n s he l l a ge s f r om a v a r ie ty o f s he l lf i sh s pec ie s l i v ing i n ac a lca reous e nv i ronmen t ( F igu r e 6 . 1) . A s l i me s tone s t ra ta a r e e x tens ive i nN ew Z ea land , t h e h a rd w a te re f f ec t i sp r obab ly mo re o fa c once rn t oa r chaeo log i s t s t han u pwe l l ing . I nc on t ra s t t ot h i s e nv i ronmen t , a r chaeo log ica l s i te s a t A o tea , P onu i I s land , L iga r B ay a nd S awp i t P o in t I n le t w e re s amp led , a s t h e se s i t e s a r e f r ee o f c a lca reous r ock . I n d a t ing t h e s i te s u s ing b o th c ha r coa l a nd m a r ine s he l l , i s sue s i nr a d ioca rbon d a t ing N ew Z ea land p r eh i s to ry , s uch a s i n bu i l t a ge o f c ha rcoa l , c ou ld a l so b e a dd re s sed . D e ta i led d e sc r ip t ions o f t h e g eo logy s u r round ing t h e s i t e s a nd e nv i ronmen ta l c ond i t ions d u r ing t h e i r f o rma t ion , a r e p r e sen ted . T h i s i si mpo r tan t t o e xp la in a ny a noma lous s he l l a nd c ha r coa l a ge s w h ich may b e d ue t ot h e e nv i ronmen ta l c ond i t ion ss u r round ing t h es i te s i np r eh i s to ry .

N o r th land b o th i n p reh i s to r ic a nd h i s to r ic t imes ( Tay lo r 1 995 :3) . T he s i te s i t s u pon a r i dge k nown a s Wa ia roh ia P o in t , o n t h e e a s tern s i de o ft h e h a rbou r , l o ok ing a c ro s s t o t h e m a s s ive s and d une c omp lex o n t h e o ppo s i te s i de o ft h e w a te r ( Tay lo r 1 995 :5 ) ( F igu re 6 . 3 ) . T he r i dge i t se lf o nce e x tended t o t h e s e a a nd c on ta ined a n umbe r o f a r chaeo log ica l f e a tu re s , b u t m any w e re d e s t royed w hen t h e e nd o f Wa ia roh ia P o in t w a s r emoved t om ake w ay f o r S t a te H ighway 1 2 ( Tay lo r 1 995 :5 ) . O n t h e s u rv iv ing s e c t ion o f r i dge , f ew p r eh i s to r ic f e a tu r e s n ow r ema in d ue t o t h e b u i ld ing o fr o ad s a nd h ou se s o n t h e s i t e i nt h e e a r ly 1 960 s a nd 1 989 ( Tay lo r 1 995 :5 ) . T ay lo r e xcava ted f i ve a r ea s i n 1 99 1 o n t h e r ema in ing u nd i s tu rbed p o r t ion o ft h e r i dge . T he se e xcava t ions s howed t h a t t h e r i dge top a c ted a s ak a inga i n p r eh is to ry , w he re a c t iv i t ie s s uch a s f i sh ing , f o od p r epa ra t ion , c ook ing , a dze m ak ing a nd g a rden ing t o ok p l ace . T he A r ea 3 e xcava t ion w a so fp a r t icu la r i mpor tance i nd e term in ing ac h rono logy f o r t h e s i te . T h i s l o ca t ion c on s t i tu ted a l a rge mound o n t h e w e s tern e dge o ft h e r i dge m ea su r ing 1 0 x6 m i na r ea , a nd w a s e xcava ted a s t wo s qua r e s , t h e U ppe r M idden a nd t h e L owe rM idden ( Tay lo r 1 995 :8 ) . T he L owe rM idden r e vea led f ou r d i s t inc t ive l a ye r s o fo ccupa t ion , a nd c on ta ined aw ide v a r ie ty o fs he l lf i sh s pec ie s a nd c op iou s a moun t s o fc ha rcoa l ( F igu re 6 . 4 ) . A r a d ioca rbon d a te (Wk 1086 ) a l ready o b ta ined b y T ay lo r o n P aph ie s a u s t ra l i s f r om L aye r 4o f t h i s m idden g ave a c a l ib ra ted a ge o f 1 4 11 -1 477 c a l AD 2° .T he L owe r M idden w a s s amp led f o r t h is s t udy b ecau se o f t h e v a r ie t ie s o f mo l lusc a nd l a rge q uan t i ty o fc ha rcoa l p r e sen t , a sw e l l a sa n a l r eady e x is t ing r a d ioca rbon c h rono logy . Ma te r ia l f o r d a t ing w a so b ta ined f r om L aye r s 2t o5 .

S amp le p rovenance i s av i ta l f a c to r w hen c ons ide r ing t h e r e cove ry o f s amp le s f r om a r chaeo log ica l s i t e s . T h i s e n ta i ls n o t o n ly c onf i rm ing t h a t t h e c ha rcoa l /ma r ine s he l l p a i r s a r e f r om e xac t ly t h e s ame l o ca t ion , b u t a l so t h a t t h e c u l t u ra l l a ye r s amp led h a s b een u nd i s tu rbed s i nce d epo s i t ion a nd r e p r e sen t s as i ng le h uman induced e ven t . S i te s f o rt h i s s t udy w e re c ho sen w i th t h is c r i te r ia i nm ind .

E ach l a ye r o f t h e L owe r M idden c on ta ined e x ten s ive a moun t s o f s he l l , h ang i s t one s , b one a nd c ha rcoa l , b u t a l though s im i la r i n c on ten t , t h e l a ye r s d i f f e r ed i n m a t r ix . L aye r 2w a s " b lack a nd s t i cky " , i t s c on s t i tuen t s b e ing m o re b roken a nd m ixed t h an t h e l owe r l a ye r s . M idden i nL aye r 3 w a s m ixed w i th a c l ean b r own s a nd , w h ich p o s s ib ly o r ig ina ted f r om t h e t op o ft h e r i dge , a nd w a s u sed t oc ove r t h em idden i np r eh i s to ry f o ro ccupa t ion . T he L aye r 4m idden c on ta ined l i t t le s and , a nd w a s c ove r ed b y ad i s t inc t ive c l ean c oa r se y e l low s and w h ich s e a led i tf r om L aye r 3 . L aye r 5 c omp r ised o fm idden m ixed w i th ac l ean y e l low s and w h ich o r ig ina ted f r om p eop le l i v ing u pon t h en a tu ra l g round

A l l a r chaeo log ica l s i te s o n P onu i I s land a nd L iga r B ay w e re e xcava ted a nd s amp led b y at e am w h ich i n c luded t h e a u tho r . T he K okohu ia s i te w a s v i s i ted a f t e r c omp le t ion o f t h e e xcava t ion , a nd s amp les s e lec ted f o r d a t ing b yt h e e xcava to r a nd t h e a u tho r . T he t wo s i te s o n A o tea a nd t h e S awp i t P o in t s i te , w e re s amp led b y a r chaeo log i s t s i n vo lved i n t h e e xcava t ion s . KOKOHU IA ( 006 /317 ) , OPONON I Archaeo log ica l Excava t ion a nd Ana lys is K okohu ia i sl o ca ted 4 k m f r om t h e m ou th o ft h e H ok ianga H a rbou rn ea rO ponon i , No r th land ( F igu r e s6 . 1 a nd 6 . 2 ) . T he s i te i sc on s ide red a n e a r ly s e t t lemen t i n Mao r i t r ad i t ion . I t s l o ca t ion p rov ided a r ou te t o r e sou rce s i nt h e h i n te r land o f

S he l l CRA c a l ib ra ted u s ing t h e m ode l led m a r ine c ur ve ( S tu ive ra nd B raz iuna s 1 993 )a nd N ew Z ea land A Rv a lue o f2 5 ±1 5( H igham a nd H ogg 1 995 ) . 2 0

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A rchaeo log ica l E xcava t ions

CHAPTER 6

F igu re 6 . 1 . L oca t ion o fa r chaeo log ica l s i t e ss amp led f o rc ha r coa l /ma r ine s he l l p a i r s i nt h is s t udy .

4 8

A r cha eo log i ca l E xcava t ion s

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F igure 6 . 2 . L oca t ion o f Kokohu ia i nt h e H ok ianga H a rbou r , N or th land .

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4 9

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A rcha eo log ica l E xcava t ions

CHAPTER 6

M 1 1

L aye r4 .D en se c l ean s he l l i n y e l low /b lack s a ndy ma t r ix . C ha rcoa l /ma r ine s he l l p a i r

L aye r I .T op so i l L aye r2 .B lack s and w i th d en se s h e l l , c ha r coa l a nd h ang i s t one s . C ha r coa l /ma r ine s he l l p a i r

L en se o fs t e r i le y e l low s and L aye r5 a . M idden w i th s he l l , c ha rcoa l a nd h ang i s t one si n ac l ean y e l low s and . C ha rcoa l /ma r ine s h e l l p a i r

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k umu ( Red G uma rd ) , P a raperc i s c o l ia s ( B lue C od ) , T hyr s i te s a tun ( Ba r racou ta ) , S e r io la l a land i ( K ingf i sh ) , L a tr i s l i nea ta ( T rumpe te r f i sh ) a nd s ha rk ( u nknown s p ec ie s ) ( Tay lo r 1 995 ; 11) . B i rd a nd m amma l b one i d en t if ied f r om t h e s i te i n d ica ted t h e e xp lo i ta t ion o fN e s tor m e r id iona l i s ( Kaka ) , C a l laea s c i ne rea ( Kokako ) , R a t tu s e xu lan s ( K io r e ) a nd C an i sf am i l ia r i s ( Ku r i ) t h roughou tt h e o ccupa t ion o ft h e s i te , a sw e l l a sp o s s ib ly moa ( unknown s pec ie s ) d u r ing a c t iv i t ie s i nL aye r5 .

s u rf ace a nd c hurn ing t h e s a nd u p w i th t h e i ra c t iv i t ie s ( Tay lo r 1 995 :9 ) . T ay lo r n o ted t h a t e ach m idden l a ye r h ad p ocke t s o f s i ng le s p ec ie s o fs he l lf i sh w h ich h ad b een e xp lo i ted a nd c onsumed . T he s he l l f r om t h e l a ye r sa l so l o oked f r e sh , a nd r e ta ined t h e i r o r ig ina l c o lou r ing ( Tay lo r 1 995 :9 ) . T yp ica l f e a tu re s f o und i n t h e c u l tu ra l l a ye r s w e re f i re s , e spec ia l ly i n L aye r 5w h ich c on ta ined a n umbe r o f o ve r lapp ing f i re s coop s , a s w e l l a s a s soc ia ted f i shhook s . A r tef ac t s r e cove red d u r ing t h e e xcava t ions i n c luded 3 1 p i ece s o fs he l l f i shhook s , as e c t ion o fb one l u re a nd af u l l s he l l l u re , o b s id ian f l ake s f r om n on l o ca l s ou r ce s , ab eve l f r om a n a dze i n L aye r 2 , t wo s ma l l l i me s tone a dze s ( one f r om L aye r 3t h e o t he r f r om L aye r 4 ) , a nd aD uf f I A b l ack a r g i l l i te a dze f ound i nL aye r 5( Tay lo r 1 995 :10 , 16 ) .

F rom t h e a r chaeo log ica l e v idence , T ay lo r i n t e rp re ted A r ea 3 a s af ood p r epa ra t ion , c ook ing a nd c onsump t ion a r ea , a nd e ven t h ough t h e c u l tu ra l e ven t s w e re d i s t inc t ive , t h ey p o s s ib ly o ccur red w i th in a f ew y ea r s ( Tay lo r 1 995 :12 ) . A c t iv i ty o n t h is a r ea o f t h e r i dge w a s b e l ieved t o h ave o ccu r red i nt h e l a te A rcha ic , b a sed o n t h e f i sh h ook a nd a dze t ypo log ie s , a nd t h e s i ng le r a d ioca rbon d a te ( T ay lo r 1 995 :17 ) . F ur the r r a d ioca rbon d a t ing w ou ld c onf i rm t h eb eg inn ing a nd d u ra t ion o fo ccupa t ion o n t h e s i te .

S he l lf i sh s pec ie s p r e sen t i n a l l l a ye r s i n c luded P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbury i , V ene rup i s l a rg i l l ie r t i , L une l la s ma ragda , C om ine l la v i rga ta , P e rna c ana l icu lu s , Maor ico lpu s r o seu s , C e l lana s p . , Me la rapha o l i ze r i , Amph ibo la c rena ta a nd H a l io t i s i r i s . F i sh s pec ie s e xp lo i ted w e r e a s v a r ied a s t h e s he l lf i sh . P ag ru s a ura tu s ( Snappe r ) w a s t h e m o s t c ommon s pec ie s t a ken , e qua l i np ropo r t ion t o A ld r iche t ta f or s te r i ( Ye l low -eyed Mu l le t ) a nd Mug i l c epha lu s ( G rey Mu l le t ) c omb ined . N emadac ty lu s m ac rop te ru s ( Ta rak ih i ) , A r r ip i s t r u t ta ( Kahawa i ) , P seudoca ranx d en tex ( T reva l ly ) , T rachuru s d ec l ivu s ( J a ck Macke re l ) a nd L abr idae s p . w e re t h e o t he r ma in s pec ie s i d en t if ied . A lso f o und i nt h e m idden w e re C he l idon ich thy s

Env iron men ta l R econs truc t ion D u r ing i t s o ccupa t ion , K okohu ia w a s s ur r ounded b y c oa s ta l a nd l ow land k au r i -podoca rp -ha rdwood f o r e s t c on ta in ing t h e l a rge t r ee s A ga th i s a u s t ra l i s ( Kau r i ) , B e i l schm ied ia t a ra i r i ( Ta ra i r i ) , B e i l schm ied ia t awa ( Tawa ) , V i t ex l u cen s ( Pu r i r i ) , E laeoca rpus d en ta tu s ( H inau ) a nd P rumnop i ty s t a x if o l ia ( Ma ta i ) . A s soc ia ted w i th t h e se l a rge t r ees w e r e s ma l le r t r ee s a nd s h rub s t y p ica l o ft h is h ab i ta t , s uch a sP lag ian thu s r eg iu s ( Mana tu ) , Me l icy tu s r am i f loru s ( Mahoe ) a nd P seudopan c v c c ra ss if o l iu s ( Ho roeka ) f i l l ing t h e m id -canopy u p t o 1 5

5 0

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A rchaeo log ica l E xcava t ions

m e t re s . T he l owe r c anopy a nd f o res t m a rg in s c on s i s ted o f L ep to spermum s copar ium ( Manuka ) , K un zea e r ico id e s ( Kan u ka ) , D odonaea v i sco sa ( Ak eake ) , M y r s ine a u s t ra l i s ( Mapau ) , P seudopanax a rbo reu s ( Puahou ) , O lea r ia s pec ie s a nd M ida s a l i c if o l ia ( Ma i re ) . P ar t icu la r t o t h e c oa s t a nd d i rec t ly a s soc ia ted w i th t h e s i te w e re Me t ro s id e ro s e xce l sa ( Pohu tukawa ) , H ebe s pec ie s a nd A v i cenn ia m a r ina v ar . r e s in if e ra ( Manawa ) , p o s s ib ly f r om a l ong t h e s ho re c l o se t o t h e s i te . S eed s f o und t h rough a l l l e ve ls o ft h e s i te , b u tm a in ly i n L aye r 4 , i n c luded V i tex l u cen s , E laeoca rpu s d en ta tu s , P odocarpu s f e r rug ineu s ( M iro ) a nd B e i l schm ied ia t awa , a ga in s how ing ac l o se a s soc ia t ion o ft h e s i t e w i th t h e f o re s t . T h is r e cons t ruc t ion o ft h e p r eh is to r ic v ege ta t ion a tK okohu ia b a sed o n c ha r coa l i d en t if ica t ions , i sa l so s uppo r ted b y e a r ly h i s to r ic r e co rd s o f t h e H ok ianga h a rbou r w he r e af o re s ted l a nd scape w a s n o ted f o r i t s f l ax a nd k au r i r e sou r ce s ( Tay lo r 1 995 :2 ) . T h i s l a nd scape s t and s i nc on t ra s t t ot oday 's s c rub c oa ted h i l l s ide s .

K okohu ia s i te c on s i s t s o f s ed imen t s w i th ah i gh c a lca reou s c on ten t . T he re i st h e ref o re t h e p o s s ib i l i ty o f ah a rdwa te r e f f ec t u pon s he l lf i sh , n o t o n ly f r om w i th in t h e h a rbou r i t se lf , b u t f r om t h e f l uv ia l i n pu t , s u ch a s t h e n ea rby Wa ia roh ia s t ream , w ho se c a tchmen t i n c lude sc a lca reous T er t ia ry r o ck .

A s n o ted a bove , aw ide v a r ie ty o f s h e l lf i sh s p ec ie s w e re i d en t if ied f r om K okohu ia . T he h ab i ta t s o f t h e se s pec ies s ugge s t s t h a t K okohu ia w a s s u r rounded b y av e ry d i f f e ren t m a r ine e nv i ronmen t i n p r eh is tory t h an o b served t o day . A l l r o cky a nd s a ndy s ho re s he l lf i sh s pec ie s w e re a va i lab le t ot h e p r eh i s to r ic o ccupan t s ( Tay lo r 1 995 :2 ) . T he r e duced s he l lf ish v a r ie ty t oday i sp robab ly d ue t oh i l ls ide e r o s ion f r om f o re s t c l ea rance a nd r oad ing a c t iv i t ies ( Tay lo r 1 995 :2 ) . F i sh s pec ie s c augh tt o day a r e s im i la r i nv a r ie ty t ot h o se c augh t i n p r eh is to ry w i th s nappe r , k ahawa i , m u l le t , a nd c od s t i l l a va i lab le . S t rong t i da l c ur ren t s i nt h e h a rbou rr e su l t i ni n le t s a nd b ays w i th in t h e h a rbou r b e ing w e l l f l ushed . H oweve r , i t i sp o s s ib le t h a t t h i s s c ena r io w a s d i f f e ren t i n p r eh is to ry , b ecause o ft h e l a ck o fs andy s ho re s he l lf i sh , a nd d om inance o fr o cky s ho re s he l lf i sh s pec ie st oday .

T hree a r ea s ( A , Ba nd C ) f r om t h e f i ve e xcava t ion s w e r e c ho sen f o r s amp l ing t oi n ve s t iga te t h e d a t ing o fm a r ine s he l l o n A o tea ( F igu r e 6 . 6 ) . A rea s Aa nd B o f s i te S 8 / 17 1 w e re l o ca ted o n an a tu ra l t e r race n ex t t o ac r eek w h ich f l ow s i n to t h e Whangapoua e s tua ry . A r ea C o fs i te S 8 / 16 w a s l o ca ted 6 00 m t ot h e e a s t o fAa nd B o n a n a r t if ic ia l t e r race o f ap a s i te . T he a ge o f A rea s A a nd B w e r e e s t ima ted a tc a . 2 50 y ea r s B P , b a sed o n d epo s i t d ep th a nd o b s id ian h yd ra t ion d a te s . A r ea C w a s t hough t t o b e < 300 y ea r s o l d , b a sed o n d epo s i t d ep th , o b s id ian h yd ra t ion d a te s , a nd b ecause i tw a s a p as i te , c ons truc t ion w ou ld h ave b een a f t e r 1 500 AD ( F igu re 4f r om McGh ie 1 994 :25 ) ( s ee S chm id t 1 993 :58 ; 1996a ) .

AOTEA Archaeo log ica l E xcava t ions a nd Ana lys is T he l a rge i s land o fA o tea , o r G r ea t B a r r ie r I s land , i sl o ca ted 2 0 km n or th o f t h e C o romande l P en insu la ( F igu re 6 . 1 a nd 6 . 5 ) . E xcava t ions w e re u nder taken i n1 994 b y t h e U n ive r s i ty o f A uck land A n th ropo logy D epa r tmen t , a tf i ve l o ca t ion s a t Whangapoua o n t h e n o r th e a s te r n s ho re o fA o tea . T he a im s o f t h e e xcava t ion s w e re t o t e a ch a r chaeo logy s t uden t s e xcava t ion a nd m app ing t e chn ique s , a nd t o c ompa re t h e d a t ing m e thod s o f o b s id ian h yd ra t ion a nd r a d ioca rbon d a t ing .

T he K okohu ia s i te p rov ide s a n i n te r e s t ing s t udy i n to t h e e f f ec t o f a c a lca reou s g eo logy o n t h e d a t ing o f a n a r chaeo log ica l s i te . K okohu ia r e s t s u pon t h e r i dge o f a P l e is tocene c on so l ida ted a nc ien t s and d une o fH awe ra a ge , o ve r la in b y H o locene d une s and d epo s i t s ( M i l l igan 1 959 : Map I a ;K ea ra nd H ay 1 96 1 ; T ay lo r 1 995 :1-2 ) . T he Mo ta tau G roup f o rma t ion o ft h e L owe r O l igocene l i e s b enea th t h e se d une d epo s i t s , a nd c on ta in s a rg i l la ceous a nd c r y s ta l l ine l i me s tone w i th g l aucon i t ic s and s tone b eds ( Kea r a nd H ay 1 96 1 ; T homp son 1 978 :444 ; T ay lo r 1 995 : 1-2 ) . T he se l i me s tone a nd s a nd s tone b ed s e x tend o u t i n to t h e h a rbou r t o t h e w e s t o ft h e s i te , c r ea t ing a r ocky s ho re c ove r ed b y t h e s h if t ing s a nd s o f t h e h a rbou r . T o t h e e a s t o f t h e s i te a nd i n land , l i e b ed s o f c a lca reous s and s tone s a nd s i l t s tone s a s w e l l a st h em a s s ive U ppe rC r e taceous T ang ihua V o lcan ics o f m a r ine o r ig in ( Cha l l is 1 978 :628 ) . E x tend ing 2 5 k m u p t h e l e ng th o f t h e h a rbou r , t h e d om inan t r o ck f o rma t ion f ound e xpo sed f r om t h e e dge o ft h e h a rbou r a nd i n land c r ea t ing a b uf f e r o f n o t l e s s t h an 5 km w ide o n e i the r s i de , a r e s ed imen t s o f t h e Ma ta S e r ie s f o rmed d u r ing t h e L a te Me sozo ic ( Hay 1 978 :368 ) . T h is s e r ie s c ons i s t s o fh a rdened d a rk s i l iceou s s ha le s , o ve r la in b y c onc re t iona ry m icaceous s a nd s tone w i th c a rbona ceous b and s , c on ta in ing f l o ra l a nd f a una l f o s s i l m a te r ia l f r om ma in ly t h e H aumu r ian S tage , w i th am ino r P i r ipauan S t age p r esence ( Kea r a nd H ay 1 96 1 ; S t even s 1 978 :362 -366 ; H ay 1 978 :367 -368 ) . O the r t h an t h e m a s s ive r e cen t d une f o rma t ion s o n t h e w e s te rn s i de o ft h eh a rbou ra nd t h e mo re a nc ien td une s u pon w h ich t h e s i te i t s e lf r e s t s , t h e g eo logy s u r round ing t h e 5 1

T he A rea A e xcava t ion m ea su r ed 4x8m a nd w a s s epa ra ted f r om t h e A rea B 4 x 6 m e xcava t ion b y a 1m b au lk . E a ch a r ea c on ta ined as i ng le w e l l d ef ined l a ye r o fm idden ( Laye r 2 ) , u nde r w h ich l a y a no the r t wo c u l tu ra l l a ye r s c on ta in ing e v idence o fs t ruc tu re s a nd m ino r a moun t s o fs he l l ( Laye r s 3 a nd 4 ) ( F igu re 6 . 7 ) . S t ra t ig raph ic a na ly s is s howed t h e L aye r 2m iddens w e re c on t iguou s , t h ough A rea B h ad a g r ea te r c oncen t ra t ion o fm idden d epo s i t . B enea th L aye r 2i na r ea s A a nd B , ab roken l e n s o f c l ay / so i l m ix ( Laye r 3 ) w a s i d en t if ied i nw h ich d ra in /d i tch f e a tu re s e x tend ing f r om t h e s ou th -we s t c orne r o f A rea B i n to t h e n or th -ea s t c or ne r o f A rea A w e re f ound . Ah ang i w a s a l so i d en t if ied i nt h i s l a ye r i n A rea A , a nd t wo s ma l l f i re p l a ce s ( po s s ib ly h ea r ths ) i n A rea B . I n A r ea A L aye r 4 ( n a tu ra l ) , t wo p i t s w e re u ncove r ed , e ach a s soc ia ted w i th d r a in s a nd o ne w i th as e r ie s o f p o s tho le s . A l a rge h ome s tead b u i l t o ve r t h e s i te i n E u ropean t ime s w a s r e p re sen ted b y t h ree l a rge p o s tho le s f ound i nt h eb o t tom l a ye ro fA rea A ( G rey 1 994 ) . G rey ( 1994 :5 ) i n te rp re ted t h e p r eh i s to r ic o ccupa t ion s equence o nt h et e r race a sb eg inn ing w i th t h e c ons t ruc t ion o f p i t s i nA r ea A ( Laye r4 ) . T h i s w a s f o l lowed b y f i l l ing o ft h e p i t s i nA rea A a t al a te r t ime , t h e b u i ld ing o fh ang i i nA r ea s A a nd B , a nd t h e d igg ing o f d r a in /d i tche s a c ro s s A a nd B ( Laye r 3 ) . M idden t h en b u i l t u p a c ro s s b o th a r ea s ( Laye r 2 ) c oncen t ra ted m a in ly i n A r ea B . F i na l ly , ah ome s tead w a s b u i l t o ve r t h e s i te i n h i s to r ic t i me s ( G rey 1 994 :5 ) . T he m idden w a s d om ina ted b y t h e s h e l lf i sh s pec ie s P aph ie s a us t ra l i s a nd A u s t rovenu s s t u tchbu ry i , w i th l e s se r a moun t s o fP aph ie s s ub t r iangu la tum . P seud oca ra rv c g eorg ianu s w a s t h e d om inan t f i sh s pec ie s e xp lo i ted i n A r ea s A a nd B , f o l lowed b yA r r i sp i s t r u t ta a nd P ag ru s a ura tu s , w i th P a r ika s caber ( Kok i r i )b e ing o fm ino ri mpo r tance ( Ke r r 1 994 :19 ) .

A rchaeo log ica l E xcava t ions

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CHAPTER 6

A rchaeo log ica l E xcava t ions

Many h ang i s t one s w e re a l so f o und i nt h e m idden , a nd , n ea r t h e b a se o fL aye r 2i nA r ea A , t h ree a dze s a nd 3 50 o b s id ian f l ake s( G r ey 1 994 :3 ; E lzenaa r 1 994 :16 ) .

s p ec ie s w h ich w e re e x tens ive a l ong t h e e a s tern c oa s t o ft h e i s l and . T h is f r inge o fk anuka a nd m anuka t h en g ave w ay t o k au r i -podoca rp -ha rdwood f o r e s t i nt h e i n te r io r .

S amp le s f o rd a t ing w e re t a ken f r om L aye r 2o fb o th a r ea s t o c onf i rm t i me o fo ccupa t ion o ft h e s i t es a nd t oc ompa re w i th o b s id ian h yd ra t ion a ge s f r om t h e s ame p rovenance .

F rom a n a na ly s is o f t h e m a r ine f a una l a s semb lage s , t h e modern m a r ine e nv i ronmen t a ppea r s t ob e s im i la r t ot h a t i n p r eh i s to ry . P aph ie s a u s t ra l i s a nd A u s t rovenu s s t u t chbury i o ccu r i n c l o se p rox im i ty t o t h e s i te t o day a s i n t h e p a s t . P aph ie s s ub t r iangu la tum a r e s t i l l a va i lab le o n t h e b each t o t h e n o r th o ft h e s i te s . T he l ow o ccur rence o ft h is s p ec ie s i n t h e p r eh is to r ic r e co rd , h oweve r , m ay b e d ue t o r e s t r ic ted a va i lab i l i ty o n t h e o ppo s i te s i de o ft h e e s tua ry . F i sh s p ec ie s c augh t t oday a r e a l so p re sen t i nt h e s i te i n f er r ing c on s i s ten t a va i lab i l i ty . T he h a rbou r e nv i ronmen t w a s p robab ly s im i la r t ot o day , a l though i n f i l l ing o fp a r t o ft h e n or th w e s t s e c t ion o ft h e e s tua ry b y s ed imen t s t h rough p a s t l o gg ing a nd r e cen t a c t iv i t ie s , h a s p o s s ib ly r e duced t h e s i ze o f t h e e s tua ry ( P re s ton -Thoma s 1 994 :12 ) .

T he A r ea C 3x6m e xcava t ion y i e lded t wo c u l tu ra l e ven t s : t h e c on s t ruc t ion a nd u se o f ap i t ( Laye r 3 ) , f o l lowed b y f i l l ing o ft h ep i tu s ing s o i l a nd m idden t ol e ve l t h et e r race f o r o ccupa t ion ( Laye r 2 )( F igu re 6 . 8 ) ( G rey 1 994 :7 ) . T he L aye r 3p i t w a s d ug i n to t h e n a tu ra l s o i l s ub s t ra te , a nd i n c luded a d ra inage s y s tem a nd a s soc ia ted p o s tho le s . T he p i ta nd t e r race f i l l ( Laye r2 )c on ta ined s he l l , c ha r coa l a nd h ang i s t ones f r om c ook ing a c t iv i t ie s . S he l lf i sh s pec ie s f r om L aye r 2 w e re d om ina ted b y P aph ie sa u s t ra l i sa nd A u s t rovenu ss t u tchbu ty i . P aph i e s s ub t r iangu la tum w a s a m ino r e l emen t o f t h e m idden . T he m a in f i sh s pec ie s e xp lo i ted w a s P seudoca ranx g eo rg ianu s , t h e m idden a l so c on ta in ing s ma l le r a moun t s o f P ag ru s a u ra tu s a nd P a r ika s cabe r ( Lea the r J a cke t ) ( Ke r r 1 994 :19 ) . O b s id ian a ccoun ted f o r t h e a r t if ac tua l ma te r ia l r e cove r ed a nd p robab ly c ame f r om b o th Mayo r I s land a nd A o tea s ou r ce s . S amp le s f o r d a t ing w e re t a ken f r om L aye r 2 t od e te rm ine w hen o ccupa t ion o ft h et e r race h ad o ccur red . Env iron menta l Recons truc t ion I nc on t r a s tt ot h ed ense f o re s t s u r round ing t h e K okohu ia s i te , Whangapoua r e p r e sen t s as i te i mmed ia te t os c rub a nd c oa s ta l s pec ie s .T he se i n c lude f o re s tf r inge a nd s c rub s pec ie s s uch a s K un zea e r i co id e sa nd L ep to spe rmum s copa r ium ( dom ina te s ) , a nd D odonaea v i sco sa , C opro sma , O lea r ia a nd H ebe g enu s s pec ie s ( c o -dom inan t ) . T he c ommon e s tua r ine p l an t A v i cenn ia m a r ina v a r . r e s in if e ra w a s a l so i d en t if ied . L a rge r k au r i -podoca rp -ha rdwood s pec ie s s uch a s A ga th i s a us t ra l i s a nd B e i l schm ied ia t a ra i r i i n d ica te a f o re s t i n land f r om t h e s i te s . H i s to r ic r e co rd s a t te s t t o t h e c u t t ing o f k anuka a nd manuka f o r f i rewood f o r A uck land c i ty , t h e reby i lus t ra t ing t h e w ide sp read d i s t r ibu t ion o f t h e se s pec ie s o n t h e c oa s ta l ma rg in s ( Ha r low 1 994 :13 ) . T hou sand s o f h ec ta re s o f k au r i w e r e e x ten s ive ly l o gged o n E u ropean a r r iva l m a in ly f r om t h e w e s t c oa s t o ft h e i s land ( Ha r low 1 994 :15 ) . T he c ha rcoa l i d en t if i ca t ion s f r om t h e s i tes a s w e l l a st h e h i s to r ic r e co rd s , t h e r ef o r e , i n d ica te t h es amp led s i te sw e re c l o se t of o re s t e dge

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T he g eo log ica l s t ra ta u nde r ly ing t h e Whangapoua s i t e s i s t y p ica l o f t h e w ho le i s land . T he s i te s s i t u pon a n U ppe r Q ua te rna ry h i gh l e ve l t e r race o f a luv ium f o rm ing t h e H awe ra S e r ie s , w h ich e x tend s u p t o 7 5m a bove s e a l e ve l ( Thomp son 1 960 ) . A cco rd ing t o F l em ing a nd H a r r is ( 1978 :549 -550 ) , t h e H awe ra S e r ie s s how s e v idence o fw a rm a nd c o ld c l ima te e p i sode s , w he re l i t to ra l ma r ine d epo s i t s w e re l a id d own w i th t h e r i s ing a nd f a l l ing o f s e a l e ve l s . L y ing b enea th t h i s a l luv ium a nd d om ina t ing t h e g eo logy o f A o tea , a r e t h e M iocene B eeson 's I s land V o lcan ic s , c on ta in ing a nde s i t ic b r ecc ia s , t u f f s a nd a gg lome ra te s ( Thomp son 1 960 ; Wa t te r s 1 978 :639 ) . T hough n o t d i re c t ly i n a s soc ia t ion w i th t h e a r chaeo log ica l s i te s u nde r i n ve s t iga t ion , t h e Moehau F o rma t ion i st h e o n ly m a jo r o u tc rop o fJ u ra s s ic d epo s i t s o n t h e i s land , b o rde r ing t h e M iocene B ee son 's I s land V o lcan ic s , a nd f o rm ing t h e t i p o f A o tea f r om t h e n o r the rn e dge o f Whangapoua b each o nwa rd s . T h i s b ed i s d om ina ted b y d a rk l i t h ic -vo lcan ic g r eywacke s a nd s tone , i n te rbedded w i th a rg i l l i te s , s ha le s a nd c ong lome ra te s o f a nde s i te a nd g r an i te , a nd i sc a rbona te f r ee ( Thomp son 1 960 ; S k inne r 1 978 :267 ) . S t reams f l ow ing t h rough t h e se d epo s i t s a nd i n to t h e e s tua ry , t h e ref o re , p r e sen t n o r i sk o f ah a rd w a te re f f ec t .

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CHAPTER 6

A rchaeo log ica l E xcava t ions

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PONU I I SLAND Archaeo log ica l Excava t ions a nd Ana lys is P onu i I s land l i e s 3 0 km s ou thea s t f r om A uck land C i ty a nd i s o ne o f an umbe r o f i s l and s i n t h e H au rak i G u lf w i th e x ten s ive e v idence o f p r eh i s to r ic a c t iv i ty ( F igu r e s 6 . 1 a nd 6 . 9 ) . T he i s l and 's p reh is to ry s pan s f r om t h e A rcha ic t h rough t oP akeha a r r iva l ( I rw in p e r s . c omm .2 ) .F ive a r chaeo log ica l s i te s o n t h e i s l and ( F igu re 6 . 9 ) w e re s amp led i nN ovembe r 1 994 b y P rof . G . I rw in , D r . R . Wa l lace a nd D r . T .L adef oged o f t h e A uck land U n ive r s i ty A n th ropo logy D epa r tmen t , a nd t h e a u tho r . We t s i ev ing w a s u nder taken t o m ax im ise t h e r e cove ry o fc ha rcoa l f r om t h e s i te s , a low ing al a rge a moun t o fc ha r coa l t ob e r e ta ined . T he s t ra t ig raph ic s equence o fa l t h e P onu i a r chaeo log ica l s i t es c omp r i sed o fm idden d epo s i t s o n an a tu ra l b each b a se , i n te r spe r sed w i th l a ye r s o f b each s a nd o rs l ope w a sh .

S i te 2 7 w a s ab each f r on t m idden i n C r e scen t B ay a nd c on ta ined t wo c u l tu ra l d epo s i t s , b o th d i s t inc t ive i nc ha rac te r , b u t w i th n o i n te rven ing d epo s i t ( F igu re 6 . 12 a nd 6 . 13 ) . T he l owe r o f t h e d epo s i t s w a s s amp led ( Laye r 4 ) . T he L aye r 4 m idden h ad a t h ick l a ye r o f c ha rcoa l a t i t s b a se , p o s s ib ly r e su l t ing f r om ab r ief b ur n o fs u r round ing s c rub o n o r n ea r t h e s i te , c on tempo ra ry w i th d epo s i t ion o ft h e m idden ( I rw in p e r s . c omm . ) . T he s he l lf i sh s p ec ie s p r e sen t i nt h e m idden w e re r e s t r ic ted t o P aph ie s a u s tra l i s a nd A u s t rovenu s s t u tchbu ty i . No f i sh b one w a s o b served .

S i te N 43 / I w a s l o ca ted a d jacen t t oa n e s tua ry mou th w h ich o pened o u t o n to t h e l o ng s andy b each o f Mo tunau B ay ( F igu re 6 . 10 ) . T h is s i te c on ta ined t wo c u l tu ra l d epo s i t s , t h e l owe r o fw h ich ( Laye r 4 ) h ad b een p r ev iou s ly d a ted ( Tab le 6 . 1) ( F igu re 6 . 11) . T he se d e te rm ina t ions y i e lded o ccupa t ion a tc a . 5 00 y ea r s B P . L aye r 4w a s ad ense m idden c on ta in ing o n ly s h e l lf i sh a nd c ha r coa l . T h is l a ye r w a s e xcava ted a s t h ree s p i t s( A , Ba nd C ) a si n ve s t iga t ion r e vea led c hange s i n s he l lf i sh f r equency w i th d ep th . T h i s p o s s ib ly r ef lec ted a n umbe ro fs epa ra te m ea ls a tt h e s ame l o ca t ion w i th in as ho r t p e r iod o ft i me . P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbu ty i ,

2

P rof . G . I rw in , D epa r tmen to fA n th ropo logy , U n ive r s i ty o fA uck land .

5

N43 /333 w a s a l so l o ca ted i nC r e scen t B ay n ex t t o as t ream mou th 2 0 m s ou th o f S i te 2 7 . T h is s i t e h ad t wo c u l tu ra l l a ye r s s epa ra ted b y as t e r i le l a ye r o f c l ay /beach s a nd m ix w i th t a i l ing s o fe r oded s he l l ( F igu re 6 . 14 ) . T he l owe rd epo s i t ( Laye r 4 ) c on ta ined n o t o n ly m idden b u t A r cha ic a r tef ac t s i n c lud ing a s ma l l D uf f I A a dz e , as ma l l s t one c h i se l , b i rd b one a w l a nd 4 f l ake s o fo b s id ian : t h ree f r om Mayo r I s land ( g reen ) a nd t h e o t he r p e rhap s f r om a C o romande l s ou r ce ( wh i te ) . P aph ie s a u s t ra l i s a nd A u s trovenu s s t u tchbu ty i w e re t h e mo s t c ommon s h e l lf i sh e xp lo i ted , b u t n o f i sh b one w a s i d en t if ied . T he u ppe r c u l tu ra l d epo s i t ( Laye r 2 ) l a cked a r tef ac t s a nd c on ta ined P aph ie s a u s t ra l i s , A u s trovenu s s t u tchbu ty i , a nd C ra s so s trea g lomera ta , b u t n o f i sh b one . B o th L aye r s 2a nd 4w e re s amp led f o rd a t ing .

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A rchaeo log ica l E xcava t ions

F igure 6 . 10 . L oca t ion o fs i te N43 / 1 i n Mo tunau B ay , P onu i I s land .

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CHAPTER 6

A r chaeo log ica l E xcava t ions

A rchaeo log ica l S i te S and a nd Mud S and Rocks C l if f S t ream T rack Con tour

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A r chaeo log ica l E xcava t ions

CHAPTER 6

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S i te 1 4 w a s s i tua ted o n t h e s andy b each o f R abb i t B ay ( F igu re 6 . 15 ) . T h i s s i te c on ta ined t h ree c u l tu ra l l a ye r s , w i th L aye r 4b e ing s amp led f o r d a t ing ( F igu r e 6 . 16 ) . L aye r 4w a s ad ense c l ean m idden w i th in ay e l low b each s a nd a nd w a s p rof use i n P ag ru s a ura lu s b one . P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbwy i , C ra s so s t rea g lome ra ta a nd P erna c ana l icu la w e r et h es he l lf i sh s pec ie s i d en t if i ed .

( Pohu tukawa ) w e re a d jacen t t o a l l s i t e s o n P onu i . S pec ie s f r om t h e g enu s C op ro sma , Hebe , a nd O lea r ia w e re a l so p re sen t . C lo se ly b ound ing t h e s i te s w a s A ga th i s a u s tra l i s f o re s t w i th a s soc ia ted m ed ium s i zed u nder s to r ey t r ees o f B e i l schm ied ia t a ra i r ia nd Me tros id e ro s r obus ta ( V ine R a ta ) . T he P onu i s i t e s , t h e ref o re , a ppea r t ob e d i rec t ly a s soc ia ted w i th ad ense f o r e s ts im i la rt ot ha t f o und a tK okohu ia .

S i te 9 5 w a s l o ca ted n ex tt o as ma l l s t ream f l ow ing i n to S he l l B ay ( F igu re 6 . 17 ) . Two c u l tu ra l d epo s i t s ( Laye r s 2a nd 4 ) w e re i d en t if ied , e a ch c on ta in ing m idden c ons i s t ing o f c ha rcoa l a nd A u s t rovenu ss t u tchbury i( F igu re 6 . 18 ) . L aye r s2 a nd 4w e re s epa ra ted b y an a tu ra l b each d epo s i t o fg r ey s and a nd w ea the red s h e l l f r agmen t s ( Laye r 3 ) . E xcava t ion o f L aye r 2r evea led ap o s tho le w h ich e x tended d own i n to L aye r 3i mp ly ing t h e b u i ld ing o f as t ruc tu re o n t h e b each f r on t i n p reh is to ry . T he L aye r 4m idden w a s i d en t ica l i na ppea rance t oL aye r2 ,b u tc on ta ined n oh ang is t one s .

L a rge Me t ro s id e ro s e xce l sa a nd f o re s t e dge s pec ie s a r e s t i l l p re sen t t o day a t a l t h e s i tes e xcava ted . T he g r ea t k au r i f o re s t s s e en o n E u ropean a r r iva l , h oweve r , a r e l o ng g one d ue t ol o gg ing ( Romane s 1 993 ) . A l l t h e b ay s o n P onu i h ave t h e s ame s he l lf i sh s pec ie s a va i lab le t o day a s i np r eh is tory . S nappe r w a s t h e o n ly f i sh s pec ie s i d en t if ied f r om t h e e xcava t ion s ( a t S i te 1 4 ) , a nd t h i s s pec ie s i ss t i l l f i shed t oday . Due t oP onu i I s land 's l o ca t ion w i th in am a jo r s e away , a nd t h e o pen n a tu re o fi t sb ays , t i da l f l ush ing i s e ff ic ien t . T h is wa s p r obab ly t h e c a se i n p reh is to ry , t h ough a n i n c rea se i n s e d imen ta t ion o ft h e b ay s f r om e a r ly P akeha f o re s t ry m ay h ave r e duced t h e i rs i ze ( a s a t A o tea ) .

A r chaeo log ica l d epo s i t s c on ta in ing o n ly o ne s he l lf i sh s pec ies a r e a n u nu sua l f e a tu r e o f p r eh i s to r ic m iddens o n P onu i a ss e en i nt h e a bove e xcava t ions . B ecau se o ft h is , a nd t h ec l o se s im i la r i t ie s i na ppea rance o ft h e d epo s i t s , Wa l lace 2 3 a nd I rw in ( p e r s . c omm . ) s ugge s ted t h a t L aye r s 2a nd 4c ou ld r e p resen t am ix tu re o f n a tu ra l b each s h e l l a nd c u l tu ra l ly d e r ived m idden . I tw a s t h e r ef o r e d ec ided t o s amp le e ach l a ye rt oi n ve s t iga te t h is p o s s ib i l i ty .

P onu i i s as ma l l h i l ly i s l and c on ta in ing m any b ay s a l ong i t s c oa s t . T he s i t e s s amp led l i e w i th in r e cen t b ea ch d epos i t s , w h ich r e s t u pon H o locene H awe ra a luv ia . U nde r t h e se a l luv ia a r e U ppe r J u ra s s ic s ands tone a nd mud s tone s o f t h e C hambe r l in a nd Manga tang i F orma t ion s w h ich a r e f ound t h roughou t t h e i s l and , e xcep t a t R abb i t B ay ( S chof ie ld 1 979 :4 -5 ) . T he Manga tang i a nd C hambe r l in F o rma t ions a r e d e sc r ibed b y S chof ie ld ( 1978 :265 ; 1979 :4 ) a s h av ing a n a b sence o f m ac rof o s s i l s a nd m ic rof auna s . T he se s t ra ta e x tend o u t i n to t h e Wa iheke C hanne l a nd T amak i S t ra i t f o rm ing t h e s h a l low b ay so n t h e w e s te r n s i de o ft h ei s land .

E nv ironmen ta lR econs truc t ion I n p r eh is to r ic t i me s , t h e f o r e s t e dge a nd c oa s ta l s pec ie s o f K unzea e r ico id e s , L ep to spe rmum s copa r ium , P seudopanax a rboreu s ( Puahou ) , D y so xy lum s pec tab i le ( Kohekohe ) , L ophomyr tu s b u l la ta ( Rama rama ) a nd Me t ro s id e ro s e xce l sa

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CHAPTER 6

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CHAPTER 6

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CHAPTER 6

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F i gu r e6 . 2 1 . S t ra t ig raphy o fs i te N 25 /26 , L iga rB ay .

L IG AR BAY Archaeo log ica l E xcava t ions a nd Ana lys is L iga r B ay i ss i tua ted w i th in G o lden B ay a tt h e t o p o f t h e S ou th I s land ( F igu re 6 . 1) . Two s i te s l y ing w i th in 2 0 mo ft h e p resen t h i gh t i de m a rk w e r e e xpo sed d u r ing s ub -d iv i s ion a c t iv i t ie s o n f a rm l a nd ( F igu r e 6 . 19 ) . T h i s f i nd r e qu i r ed t h e s i te st ob es u rveyed a nd a s se s sed b y W . G umb ley o ft h eN ew Z ea land H i s to r ic P l ace s T ru s t i n A ugus t 1 994 , g i v ing t h e o ppo r tun i ty t o s amp le t h r ee d i s t inc t ive a r chaeo log ica l d epos i t s i nc l o se p rox im i ty t oe ach o t he r . E ach s i te w a s l o ca ted o n ab each f r on t i np r eh is to ry , o ne o n t he b each f l a t , a nd o ne o n as a nd d une . S amp le s w e re t a ken f r om t wo m idden s p r e sen t i nt h e b each f l a t s i te ( N25 /95 , M idden s 1a nd 2 ) , n ow e xpo sed 0 . 5 m b e low t h e p r e sen t g round s u rf a ce , a nd f r om a n u ppe r o ccupa t ion l e ve l f r om a s urv iv ing p or t ion o ft h ed une ( N25 /26 , L aye r4 ) . M idden 1o fs i t e N 25 /95 m ea su red a pp rox ima te ly 4 . 5 x2 x 0 . 5 m , a nd c on ta ined s he l l , f i sh b one , h ang i s t one s a nd c ha rcoa l ( F igu r e 6 . 20 ) . T h is d epo s i t l a y a s al e n s w i th in a y e l low /b rown g r an i t ic s and . P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbu ty ia nd P aph ie ss ub t r iangu la tum w e re t h e d om inan t s he l lf i sh s pec ie s p r e sen t , f o l lowed i n l e s se r a moun t s b y L une l la s ma ragda , My t i lu s e du l i s a o teanu s a nd Amph ibo la c rena ta . F i sh s p ec ie s i d en t if ied w e re P seudophyc i s b achu s ( Red C od ) , T hy r s i te s a tun ( Ba r racou ta ) a nd G enyp teru s b lacod e s ( L ing ) . T he d imens ions a nd i s o la t ion o f t h is m idden s ugge s ted as i ng le e ven t . M idden 2 w a s l o ca ted w i th in 2 m o f m idden 1 a nd w a s s im i la r i nc on ten t , c on ta in ing s he l l , f i shbone , h ang i s t one s a nd c ha r coa l ( F igu re 6 . 20 ) . T h is d epo s i tw a s a l so s e a led b y a y e l low /b rown g r an i t ic s a nd . C ommon s he l lf i sh s pec ie s p resen t w e re P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbury i ,

P aph ie s s ub t r iangu la tum , L une l la s ma ragda , My t i lu s e du l i s a o teanu s a nd Amph ibo la c rena ta . I d en t if ied f i sh w e re P seudophyc i s b achu s , T hy r s i te s a t un a nd G enyp te ru s b l acod e s . A n a dze f l ake m ade p o s s ib ly f r om D 'Urv i l le I s land a r g i l l i te w a s a l so f o und . T he e x ten t o f t h e d epo s i t ( a pp rox . 5x 2 x 0 . 4 m ) i mp l ied a no the r s i ng le p r eh i s to r ic e ven t . T he e ven t s a tM iddens 1a nd 2w e re i n te rp re ted a so ccur r ing a tt h e s ame t i me d ue t ot h e i rc l o se p rox im i ty , s im i la rv er t ica l o r ien ta t ion , a nd t h e i r i s o la t ion w i th in a s t e r i le s a nd l a ye r . T h is i n te rp re ta t ion w a sa l so s uppo r ted b y c l o se s im i la r i t ie s i n s h e l lf i sh v a r ie ty a nd s i ze , a nd c ommon f i sh s pec ie s . L aye r 4o f s i t e N 25 /26 w a s ac ompac t , s o l id i f ied m idden , c on ta in ing w ho le a nd c r ushed s he l l , f i sh b one , h ang i s t one s a nd c ha r coa l ( F igu re 6 . 2 1) . S he l lf i sh s pec ies c on s i s ted o f P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbu ty i , P aph ie s s ub t r iangu la tum , L une l la s ma ragda a nd C om ine l la a d spe r sa . F i sh s pec ie s p r e sen t w e re P seudophyc i s b achu s , T hy r s i te s a t un , G enyp teru s b lacod e s a nd P ag rus a u ra tu s . T he l a ye r s amp led ( Laye r 4 ) w a s o ne o f f ou r d i s t inc t ive c u l tu ra l e ven t s . Env iron men ta l Recons truc t ion

CHAPTER 6

A rchaeo log ica l E xcava t ions

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T ab le 6 . 2 . R ad ioca rbon d a tes f r om L aye r LI C , S awp i t P o in t( N26 /214 ) , Awa roa I n le t . 1 978 : F ig . 2 . 13 , 9 5 -96 ; B a rbe r 1 994 ) . B o rde r ing t h e v e ry w e s tern e dge o f L iga r B ay i s as ma l l o u tc rop o f T akaka L imes tone , a nd o n t h e w es ter n a nd e a s ter n ma rg ins t r ace s o f t h e Mo tup ip i C oa l Mea sure s ( Gr ind ly 1 97 1 :15) . T hese d epos i t s s i t a s al e ns u pon t h e S epa ra t ion P o in t B a tho l i th , a nd r e p resen t l i t t le r i sk a ss ou rces o fh a rdwa te rf o rt h eb ay .

P ter id ium a qu i l inum v a r . e scu len tum ( B racken f er n ) s t ood i n f o res tc l ea r ings . T h is l a ndscape i ss im i la rt ot h a t s u r round ing K okohu ia a nd P onu i i n p reh is tory , a nd i st yp ica l o f S ou th I s land c oa s ta l B eech F o res t . T h is t e r res t r ia l e nv ironmen tw a s s t i l l p r e sen to n E uropean a r r iva l ( Ba rbe r 1 994 :952 -954 ) . T he s he l lf i sh s pec ies f r om t h e s i tes i n d ica te as im i la r m a r ine e nv i ronmen t t oday a s i n t h e p a s t , w i th P aph ie s a u s t ra l i s , A u s trovenu s s t u tchbu ry i a nd P aph ie s s ub t r iangu la tum a l b e ing a va i lab le . P seudophyc i s b achus , T hyr s i te s a tun , G enyp te ru s b lacod e s a nd P ag ru s a ura tu s a r e a l so c augh t t oday .

SA WP IT PO INT ( N26 /214 ) Archaeo log ica l Excava t ion a nd Ana lys is T he S awp i t P o in ts i te ( N26 /214 ) w as l o ca ted i n Awa roa I n le t a l ong t h e G ran i te C oa s t e a s t o f L iga r B ay , a nd w a s e xcava ted b y B a rbe r f r om 1 988 -89 ( F igu re 6 . 1) . T h is s i te w a s p a r t o f ad une c omp lex c on ta in ing m idden a nd p i t s . T he m idden d epo s i t e x tended o ve r s eve ra l h undred s qua re m e te r s ( Ba rbe r 1 994 :210 ) . T he e xcava t ion i n vo lved i n ve s t iga t ion o f ap i t a nd s u r round ing c u l tura l d epos i t s t o a s cer ta in w he the r t h e p i t s h ad b een u sed f o r f ood s t o rage , a nd d e term ine t h e r e la t ionsh ip b e tween t h e p i ts a nd t h e a c t iv i t ies r ef lec ted i n t h e i ns i tu m idden d epo s i t s ( Ba rbe r 1 994 :211) .

T he L iga r B ay s i tes s i t w i th in H o locene s ands o f g ran i t ic o r ig in w h ich l i e o n B a inham F orma t ion Q ua terna ry g r ave l d epo s i t s ( Gr ind ley 1 971 :16 17 ) . B enea th t h e se g rave ls i st h e S epa ra t ion P o in t B a tho l i th o f g ranod io r i te a nd o t he r a s soc ia ted m inera ls o f L owe r C re taceous Ju ra ss ic o r ig in . I t i st h i s f e a ture t ha t d om ina tes t h e r eg ion f r om L iga r B ay e a s twa rd s a sf a r a s Mo tuaka ( G r ind ley 1 971 :10 -12 ; G r ind ley

2 4

S he l l CRA c a l ib ra ted u s ing t h e m od e l led m a r ine c ur ve ( S tu ive ra nd B ra z iuna s 1 993 )a nd N ew Z ea land AR v a lue o f2 5 ±1 5( H igham a nd H ogg 1 995 ) .

6 3

CHAPTER 6

A rchaeo log ica l E xcava t ions

T he e xcava t ion u ncove red t h ree d i s t inc t ive c u l tu ra l d epo s i t s , e ach s epa ra ted b y s t e r i le g ran i te s and a nd i n te rm i t ten t m idden c oncen t ra t ions ( Ba rbe r 1 994 :2 11) ( F igu re 6 . 23) . T he se s t ra t ig r aph ic u n i t s w e re d i s tu rbed o n ly b y t h e c on s truc t ion a nd i n f i l l ing o f a p i t . P ap h i e s a u s tra l i s d om ina ted t h e s he l lf i sh s pec ie s p r e sen t i n a l l l a ye r s . A u s t rovenu s s t u tchbu ty i , Amph ibo la c r ena ta , L une l la s ma ragda a nd C om ine l la s p . o ccu r red i n l e s se r a moun t s . P seudophyc i s b achu s a nd T hy r s i te s a tun m ade u p a lmo s t 9 0% o f f i sh s p ec ie s i d en t i f ied . Mamma l a nd b i rd r ema ins c ons is ted o f C an i s f am i l ia r i s , R a t tu s e xu lan s , D e lph inu s d e /ph i s ( Sea l ) , P uf f inu sg av ia ( Shea rwa te r ) , E ud yp tu la m inor ( L i t t le B lue P engu in ) a nd C a l laea s c i ne rea ( Kokako ) . A r tef ac t s r e cove r ed i n c luded f ou r b one b i rd s pea r p o in t s , t h ree b one f i sh h ook s , a nd s l ende rb one s haf t s , a l l made f r om d og b one ( Ba rbe r 1 994 :6 11) . D og c op ro l i te s w e re a l so i d en t if ied i nt h em idden . Two i n i t ia l r a d ioca rbon d a te s f r om L aye r L1 Cw e re r un b y t h e Wa ika to a nd I GNS l a bo ra to r ie s t o d a te f i r s t o ccupa t ion o n t h e d une ( Tab le 6 . 2 ) . T he l a rge s t anda rd e r ro r a s soc ia ted w i th t h e I GNS c ha rcoa l a ge w a s d ue t o l a bo ra to ry e r ro r ( Ba rbe r 1 994 :228 ; B a rbe r p e r s . c omm .2 5) .T he s he l l d a te , t h ough , c an b ec on s ide red t od a te t h e i n i t ia l o ccupa t ion e ven t o n t h e d une . B ecause t h e s i te w a s o f as im i la r t ype t ot ho se i n ve s t iga ted a tL iga r B ay , b u t s e t w e l l a pa r t g eog raph ica l ly , t h e re w a s a n o ppo r tun i ty t oi n ve s t iga te t h e d a t ing o fm a r ine s he l l o n a no the r s e c t ion o f t h is c oa s t l ine f r om a n a l ready d a ted c on tex t . L aye r L 1C w a s r e samp led , a nd a dd i t iona l m a te r ia l w a sc o l lec ted f r om L1 B f o rd a t ing . B a rbe rh a sn o t ed t h a ts ub -f o s s i lA u s t rovenu ss t u tchbu ty im ay b e p r esen t i n l a ye r L 1C ( Ba rbe r 1 994 :220 ; B a rbe r p e r s . c omm . ) . T h i ss h e l l m ay h ave i n t ruded i n to t h em idden d u r ing c on s t ruc t ion o f t h e p i t , a nd s o r a d ioca rbon a ge s o n A u s trovenu ss t u tchbu ry if r om L 1C m ay b ev e ry o l d . Env iron men ta l Recons truc t ion T he f o re s t c ove r p r e sen t d u r ing p r eh i s to r ic o ccupa t ion a t S awp i t P o in t w a s s im i la r t o t h e L iga r B ay s i te s . B a rbe r ( 1994 :952 ) i d en t if ied N o thof agu s a s t h e d om inan t f o res t s pec ies i mmed ia te ly s u r round ing t h e s i te w i th Me t ro s id ero s r obu s ta , L ep to spe rmum s copar ium , K un zea e r ico id e s , D odonaea v i sco sa a nd Me l icy tu s r am i f loru s b e ing t h e c ommon c oa s ta l s pec ie s ( Ba rbe r 1 995 :953 -954 ) . H e n o ted t h a t t h e f o re s tc ove rt oday i sp robab ly s im i la r t ot h a t p r e sen t b ef o re E u ropean a r r iva l , o t he r t h an s ome a r ea s c on ta in ing r e gene ra t ing s c rub ( Ba rbe r 1 994 :954 ) . L ike t h e L iga r B ay s i te s , S awp i t P o in t h a s as im i la r m a r ine e nv i ronmen t t o day a s i td i d i n t h e p a s t , w i th a l l f a una l s pec ie s i d en t if ied s t i l l b e ing p re sen t . T he g eo logy o f t h e S awp i t P o in t s i t e i si d en t ica l t o t h a t o ft h e L iga r B ay s i te s , e xc lud ing t h e m ino r p r e sence o f t h e We s thaven G roup T akaka L ime s tone a nd Mo tup ip i C oa l Mea su re s . T h is s i te s i t s w i th in a g r an i t ic H o locene s and d une u pon t h e S epa ra t ion P o in t B a tho l i th a nd s o r ep re sen t s ac a lca r eous f r ee d epo s i t ( G r ind ley 1 97 1 :10 12 , 1 5 17 ; B a rbe r 1 994 :187 , 2 11) .

2 5

D r . I .B a rbe r , H i s to r ic P lace sT ru s t , We l l ing ton .

6 4

SU M MARY T he a r chaeo log ica l s i te s s amp led a bove p rov ide a c r o s s s e c t ion o fe nv i ronmen t s f r om w h ich v a r iou s s h e l lf ish s pec ie s w e re r e sou r ced b y Mao r i i n p r eh i s to ry . D a t ing t h ese s i te s w i l l e nab le t h e i n ve s t iga t ion o f e nv ironmen ta l i nf luence s u pon s h e l l d a te s , a nd a sce r ta in w he the r t h e re a r e s pec ie s s pec if ic f a c to r s i n he ren t i na ccu ra te m a r ine s h e l l d a t ing . We may a l so o b se rve h ow c ha rcoa l a ge s r ef lec t t h e a ge o f a r chaeo log ica l e ven t s w hen c ompa r ed t o ma r ine s he l l d a te s , a nd w ha t f a c to r s m ay i n c rea se t h e i n bu i l t a ge o f i d en t if i ed c ha r coa l s amp le s .

CHAPTER 7

ANALYSIS OF RAD IOCARBON AGES FRO M EXCAVATED ARCHAEOLOGICAL S ITES

m e thod i su sed , a r e t h en e xam ined . F o r t h e se s i t e s , r e a son s a r e s ugge s ted f o r t h e a ge d i f f e r ence s b e tween t h e s amp le t y pe s .

I NTRODUCT ION I n t h i s c hap te r , t h e a na ly se s o f t h e p a i red c ha rcoa l a nd m a r ine s h e l l r a d ioca rbon a ge s f r om t h e a r chaeo log ica l s i te s e xcava ted a nd s amp led f o r t h i s d i s ser ta t ion a r e p re sen ted . E ach m a r ine s h e l l a nd c ha rcoa l CRA f r om t h e a r chaeo log ica l s i t e s h ave b een c a l ib ra ted s epa ra te ly , s o t h e e f f ec t o f t h e v a r iou s c a l ib ra t ion c urve s o n t h e c a l ib ra t ion o f i n d iv idua l r a d ioca rbon d a te sm ay b ea s ses sed .

F o r e a ch o f t h e a r chaeo log ica l s i te s d i scussed , e va lua t ions a r em ade o n : •

s im i la r i t ie s s pec ie s ;

i n r ad ioca rbon

a ge s

b e tween

s h e l lf i sh

Ma r ine s h e l l a nd c ha rcoa l r a d ioca rbon d a te s a r e s e en a s b e ing i na g r eemen t i nd a t ing a n a r chaeo log ica ld epo s i t , w hen a ge r a nge s f r om c a l ib ra ted s he l l d a te s o ve r lap w i th a ge r a nge s f r om c a l ib ra ted c ha r coa l d a te s a t l a ( s ee K i rch a nd H un t 1 988 ; K i rch , H un t a nd T y le r 1 989 ; D ye 1 990 ; A nde r son 1 99 1 ; A l len 1 994 ; A nde r son e t a l . 1 996 ) . A rchaeo log ica l s i te s w he re c a l ib ra ted m a r ine s he l l d a tes a r e i n a g r eemen t w i th c a l ib ra ted c ha r coa l d a te s , w hen u s ing e i the r t h e r e ser vo i r c o r r ec t ion c a l ib ra t ion m e thod , o r t h e mode l led m a r ine c u rve c a l ib ra t ion t e chn ique , a r e c ons ide red f i r s t i nt h i sa na ly s is .

•

v a r iab i l i ty i n r a d ioca rbon d e te rm ina t ions o f c ha r coa l s amp le s f r om t h e s ame p rovenance ;

•

t h e e f f ec t o fu s ing e i the r o ft h e t wo ma r ine s h e l l CRA c a l ib ra t ion m e thod s f o r a ccu ra te ly d ep ic t ing t h e a ge o f a na r chaeo log ica l d epo s i t .

A rcha eo log ica l s i te s w he re s ome o ft h e c a l ib ra ted c ha rcoa l a nd m a r ine s h e l l r ad ioca rbon a ge s f r om t h e s ame p rovenance d o n o t a g r ee , i re spec t ive o fw h ich m a r ine s he l l c a l ib ra t ion

C ha r coa l a nd m a r ine s he l l r a d ioca rbon a ge s f r om L aye r s 2t o 4f r om K okohu ia a r e p r e sen ted b e low ( Tab le s 7 . 1 -7 . 4 ; F igu r e s7 . 1 -7 . 4 ) .

A RCHAEOLOG ICAL S ITES W ITH C HARCOAL /MAR INE SH ELL C HRONOLOG ICAL A GREEMENT Kokohu ia ( 006 /317 )

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3 80 ±4 0 3 40 ±4 0

Wk -4486

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4 10 ±4 0

Wk -4487 Wk 3 696

C ha r coa l P aph i e sa u s t ra l i s

3 80 ±4 0

Wk -3697

A u s t rov enu ss t u tchbur y i

70 ±4 0

Wk -3698

V enerup i sl a rg i l l ier t i

6 80 ±4 0

Wk -3699

L une l la s ma ragda

7 60 ±4 0

Wk -370 1

P erna c ana l icu lu s

8 00 ±4 0

7 10 ±4 0

C a l A ge AD l a ( A tmo spher ic C urve ) 1 525 -1 562 1 629 -1 658 1 487 -1 642 1 523 -1 578 1 626 -1 653 1 450 -1 528 1 558 -1 631 1 487 -1 642 1 493 -1 602 1 6 16 -1 646 1 445 -1 522 1 583 -1 625 1 525 -1 562 1 629 -1 654 1 448 -1 526 1 56 1 -1 629 1 439 -1 492

C a l A ge AD l a ( Mode l led Mar ine C urve )

1 523 -1 646 1 479 -1 545 1 549 -1 663 1 486 -1 560 1 462 -1 520

T ab le 7 . 1 C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a g e s o n c ha rcoa l a nd m a r ine s he l l f r om K okohu ia , L aye r2 .

6 5

CHAPTER 7

A na lys is o fR ad ioca rbon Ages

Wk-3701 M M Wk-3699 M M Wk-3698 M M f1 : 1 -1

Wk-3697 M M Wk-3696 M M Wk-3701 R C Wk-3699 R C Wk-3698 R C Wk-3697 R C Wk-3696 R C Wk-4487 C h

I -

Wk-4486 C h

1

1 : 11-

Wk-4485 C h

I n

n

FH t i t i

t i 1 000

nn

100

1 200

1 300

1 400

1 500

1 600

Wk-4484 C h Wk-3695 C h

H

m i lI At i l l ' Il i l t 1 700

1 800

1 900

c a l R D

F igu re 7 . 1 . C a l ib ra ted r a d ioca rbon a ge s f r om K okohu ia ( 006 /317 ) , L aye r2 .( MM = s he l l c a l ib ra t ed b y Mode l led Ma r ine C u rve ; RC =s h e l lc a l ib ra ted u s ing R e se rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha rcoa la ge ) .

Layer 3

L ab N o .

S amp le T ype

CRA

Wk -3703

C ha rcoa l

4 10 ± 4 0

Wk -4540

C ha rcoa l

3 60 ± 4 0

Wk -454 1

C ha rcoa l

3 50 ± 4 0

Wk -3704

P aph i es a us tra l i s

7 10 ± 4 0

Wk -3705

A us trovenus s t u tchbury i

7 50 ± 4 0

Wk -3706 Wk -3707

V enerup i s l a rg i l l ier t i L une l la s maragda

7 20 ± 4 0 7 50 ± 4 0

Wk -3709

P erna c ana l icu lus

7 40 ± 4 0

C a l A ge AD 1 c r ( A tmo spher ic C urve ) 1 450 -1 528 1 558 -1 631 1 495 -1 5 13 1 5 16 -1 599 1 6 18 -1 648 1 5 19 -1 594 1 622 -1 650 1 493 -1 602 1 6 16 -1 646 1 451 -1 530 1 554 -1 633 1 489 -1 643 1 451 -1 530 1 554 -1 633 1 455 -1 455 1 478 -1 534 1 539 -1 637

C a l Age AD I l c v (Mode l led Mar ine C urve )

1 523 -1 646 1 492 -1 587 1 5 16 -1 639 1 492 -1 587 1 500 -1 6 19

T ab le 7 . 2 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ges o n c ha r coa l a nd m a r ine s he l l f r om L aye r 3 , K okohu ia .

6 6

A na lys is o fR ad ioca rbon Age s

C I 1APTER 7

Wk-3709 M M Wk-3707 M M I

n

Wk-3706 M M Wk-3705 M M

I

nI

Wk-3704 M M Wk-3709 R C Wk-3707 R C

n

n

Wk-3706 R C

ni

Wk-3705

R C

Wk-3704 R C I I Inn

I Fi l l

I 1— £11

Wk-454 1

C h

Wk-4540

C h

Wk-3703

C h

1 111111111111111111111111111111111111 1111111111111111111111111111111111111111111111111111111111

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

c a l R D

F igu re 7 . 2 . C a l ib ra ted r a d ioca rbon a ge s f r om K okohu ia ( 006 / 317 ) , L aye r3 .( M M =s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC =s he l l c a l ib ra ted u s ing R e servo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha rcoa l a ge ) .

L ayer 4

L ab N o .

S amp le T ype

CRA

Wk -3711

C ha rcoa l

3 70 ± 4 0

Wk -4482

C ha r coa l

4 50 ± 4 0

Wk -4483

C ha r coa l

4 90 ± 4 0

Wk -4542

C ha rcoa l

4 30 ± 4 0

Wk -37 12 Wk -37 13

P aph ies a u s t ra l i s A u s t rovenu ss t u tchb loy i

8 10 ± 4 0 7 50 ± 4 0

Wk -37 15

L une l la s ma ragda

7 70 ± 4 0

Wk -37 16

C om ine l la v i rga ta

7 50 ± 4 0

C a lA ge AD l a ( A tmo spher ic C urve ) 1 49 1 -1 604 1 609 -1 645 1 440 -1 493 1 603 -1 6 11 1 430 -1 452 1 46 1 -1 475 1 444 -1 520 1 592 -1 623 1 437 -1 489 1 45 1 -1 530 1 554 -1 633 1 445 -1 522 1 583 -1 625 1 45 1 -1 530 1 554 -1 633

C a lA ge AD l a ( Mode l led Mar ine C urve )

1 457 -1 5 13 1 492 -1 587 1 479 -1 545 1 492 -1 587

T ab le 7 . 3 . C onven t iona l r ad ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd m a r ine s he l l f r om L aye r 4 , K okohu ia .

6 7

CHAPTER 7

A na lys is o fR ad ioca rbon A ges

Wk-3716 M M Wk-3715 M M Wk-3713 M M Wk-3712 M M Wk-3716 R C Wk-3715 R C n

nn

Wk-3713 R C Wk-3712 R C

I— n1

Wk-4542 C h

I 1

H

Wk-4483 C h

1 1 ]-1

Wk-4482 C h n

n

Wk-3711

I HH

1 1 1 1 1l i il 1 1 1 1 t Ii lI Li l i l l i l lI L il i J il i iI l i i i l iU tL II i it i l l l i ii l l i ii ll i i 1 000

11 00

1 200

1 300

1 400

1 500

1 600

1 700

1 800

I II

C h

l tii

1 900

c a l H D

F igu r e7 . 3 . C a l ib ra ted r a d ioca rbon a ge sf r om K okohu ia ( 006 /317 ) , L aye r4 .( MM =s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; R C =s he l l c a l ib ra ted u s ing R e se rvo ir C o r rec t ion me thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

L ayer 5

L ab N o .

S amp le T ype

CRA

Ca l A ge AD l a ( Atmospher ic Curve )

Wk -3718 Wk -3719

C ha rcoa l C ha rcoa l

3 80 ± 4 0 4 40 ± 4 0

Wk -3720

C ha rcoa l

4 90 ± 4 0

Wk -3721 Wk -4543 Wk -4544

C ha rcoa l C ha rcoa l C ha rcoa l

5 10 ± 4 5 4 80 ± 4 0 4 10 ± 4 0

1 487 1 442 1 510 1 599 1 430 1 46 1 1 419 1 434 1 450 1 558

-1 642 -1 50 1 -1 5 16 -1 6 18 -1 452 -1 475 -1 447 -1 483 -1 528 -1 631

Wk -3722

P aph ies a us tra l i s

7 90 ± 4 0

Wk -3723 Wk -3724 Wk -3726

A us trovenus s t u tchbury i L une l la s maragda C om ine l la v i rga ta

8 10 ± 4 0 8 20 ± 4 0 8 40 ± 4 5

Wk -3727

P erna c ana l icu lus

8 20 ± 4 5

1 44 1 1 60 1 1 437 1 435 1 427 1 462 1 434

-1 495 -1 6 16 -1 489 -1 486 -1 452 -1 474 -1 487

Ca l Age AD l a (Mode l led Mar ine Curve )

1 467 -1 528 1 457 -1 5 13 1 451 -1 506 1 439 -1 494 1 449 -1 509

T ab le 7 . 4 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ges o n c ha r coa l a nd m a r ine s he l l f r om L aye r 5 , K okohu ia .

6 8

Ana lys is o fR ad ioca rbon Ages

CHAPTER 7

Wk-3727

MM

Wk-3726

M n

Wk-3724

MM

Wk-3723

MM

Wk-3722

MM

Wk-3727

R C

Wk-3726

R C

Wk-3724

R C

Wk-3723

R C

Wk-3722

R C

Wk-4544

C h

Wk-4543

C h

Wk-3721

C h

Wk-3720

C h

Wk-3719

C h

Wk-3718

C h

1 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

c a l R D

F igu re 7 . 4 . C a l ib ra ted r a d ioca rbon a ge s f r om K okohu ia ( 006 /317 ) , L aye r5 .( M M =s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC =s he l l c a l ib ra ted u s ing R e se rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

i mpor tan t , b ecau se i ft h e p reh is to r ic e ven t r e p re sen ted b y L aye r 5w a s d a ted u s ing o n ly as i ng le c ha r coa l s amp le , t h e t ime a t w h ich t h e e ven t m ay h ave o ccur r ed w ou ld v a ry m a rked ly d epend ing o n w h ich s amp le w a s c ho sen f o rd a t ing . T he d i f f e r ence s i nt h ef ou rc ha rcoa l a ge s m ay b e s t a t is t ica l i n n a tu re , b u t t h e t e ndency f o r r ep l ica ted c ha rcoa l r e su l t s t ob e mo re v a r iab le s ugge s t st h a t i n bu i l ta ge m ay a l so b e p l ay ing a p a r t . A nde r son ( 1991) h a s s hown t h a t e ven w hen t w ig s o f s hor t l ived s p ec ie s a r e c ho sen f o r d a t ing , i n bu i l t a ge m ay s t i l l o ccu r a nd c ause d i sc repanc ie s i nc ha r coa l a ge s f r om t h e s ame d epo s i t ( s ee C hap te r s 3a nd 4 ) . T he e nv i ronmen t m ay a l so c au se s l ow d ecay o f t w ig s , m ak ing a ge s t o o o l d . I ti s t h e ref o re p o s s ib le t h e v a r iab i l i ty i n c ha rcoa l a ge s f r om L aye r s 4a nd 5i sa s much t od ow i th i n bu i l t a ge , a ss t a t i s t ica l v a r ia t ion .

D iscuss ion o f Rad iocarbon Da tes f ro m Kokohu ia F o r e ach c u l tu r a l l a ye r a t K okohu ia , a l s he l lf i sh s pec ie s r a d ioca rbon d a ted a r e i n s t a t is t ica l a g r eemen t ( Tab le 7 . 5 ) . T h is s ugge s t s t h a t t h e s h e l lf i sh s pec ie s s e lec ted w a s n o t a n i mpo r tan t v a r iab le i nt h ea c cu racy o fr a d ioca rbon r e su l t s . A l l c ha rcoa l r a d ioca rbon d a te s f r om e ach l a ye r a t t h e s i te a r e a l so s t a t is t ica l ly i n d is t ingu i shab le ( Tab le 7 . 5 ) T he c ha r coa l CRAs , h oweve r , d o s how v a r iab i l i ty i n a ge b e tween t h e y ounge s t a nd o l de s t d a te s f r om L aye r s 4a nd 5 . I n L aye r 5 , f o r e xamp le , t h e m in imum a nd m ax imum c ha rcoa l r a d ioca rbon a ge s d i f f e r b y 1 30 y ea r s ( 3 80 ± 4 0 y ea r s B P ( Wk -37 18 ) a nd 5 10 ± 4 5 y ea r s B P (Wk -372 1) r e spec t ive ly ) . I nc on t ra s t , t h e m a r ine s he l l d a te s f r om a l t h e l a ye r s s how c on s i s tency i n a ge . T h i s o b se rva t ion i s

P rovenance

P oo led C harcoa l CRA ( A( p ) )*

T e s t S ta t i s t ic* : T ; X2n1 , 0 .05

P oo led Mar ine S he l l CRA

T e s tS ta t i s t ic* : T ; X2n1 , 0 .05

L aye r2

3 70 ± 1 8

2 . 48 ; 9 . 49

( 1 ( P ) )* 7 44 ± 1 8

L aye r3

3 73 ±2 3

1 . 29 ; 5 . 99

7 34 ± 1 8

L aye r4

0 4 35 ±2

4 . 69 ; 7 . 81

7 70 ±2 0

1 . 50 ; 7 . 8 1

L aye r5

7 4 50 ± 1

7 . 46 ; 1 .07

8 15 ± 1 9

0 . 74 ;9 . 49

5 . 83 ;9 . 49 0 . 83 ;9 . 49

T ab le 7 . 5 . P oo led m ean c ha rcoa l a nd m a r ine s he l l r ad ioca rbon a ges f r om e ach c u l tu ra l l a ye r a tK okohu ia . *= Wa rd a nd W i l son ( 1978 ) .

6 9

CHAPTER 7

A na lys is o fR ad ioca rbon Ages

P rovenance

L aye r s 2t o5

P oo led C harcoa l CRA ( A( p ) )*

T e s t S ta t i s t ic* :

3 99 ± 1 2

9 . 32 ; 7 . 8 1

T ; X23 : 0 . 05

P oo led Mar ine S he l l CRA ( A( P ) )*

T e s t S ta t is t ic* :

7 64 ± 1 4

4 . 59 ; 7 . 8 1

T ;X 23 : 0 .05

T ab le 7 . 6 . P oo led c ha rcoa l a nd m a r ine s he l l d a te s f r om l a ye r s 2t o 5a t K okohu ia h ave b een s t a t is t ica l ly c omb ined t oo b ta in a n o ve ra l l a ge f o rt h e s i te ( e r ro r i nc a l ib ra t ion c u rve i n co rpo ra ted i nc a lcu la t ion s a sr e qu i r ed i n aC a se 2 s i tua t ion ) . T he T e s t S t a t i s t ics s how t h a t t h e p oo led c ha rcoa l d a te s f r om e ach l a ye r a r e a s ag r oup s t a t is t ica l ly d i s t ingu ishab le , i mp ly ing t h a t n o t a l l t h e c u l tu ra l l a ye r s w e re d epo s i ted a tt h e s ame t ime . *= Wa rd a nd W i lson ( 1978 ) .

P rovenance

P oo led C harcoa l CRA ( A( p ) )*

A #

L aye r2

3 70 ± 1 8

3 . 8

L aye r3

3 73 ±2 3

9 . 1

L aye r4

4 35 ±2 0

5 . 2

L aye r5

4 50 ± 1 7

T ab le 7 . 7 . C lus te r a na ly s i s o n p oo led m ean c ha rcoa l r a d ioca rbon d a te s f o r e a ch l a ye r o f t h e K okohu ia s i t e ( c a l ib ra t ion c urve e r ro r t a ken i n to a ccoun t i n c l us te r a na ly s i s ) . T he d rop i nt h e Av a lue i n L aye r 4f o r t h e c ha r coa lc h rono logy i n d ica te st h a tt h ep oo led c ha rcoa ld a tes f r om L aye r s 2a nd 3c an b eg rouped s epa ra te ly f r om t h ep oo led c ha rcoa l a ge si nL aye r s 4a nd 5 . *= Wa rd a nd W i lson ( 1978 ) ; #= W i l son a nd Wa rd ( 1981) .

L ayer 2 MM

1 1 2 - 1 1 a n a l

L ayer 2 R C

1 D 1 2 1

I n -1 21

M I

L ayer 2 C h L ayer 3 M IA

1 1 3 --1

1 a l

L ayer 3 R C

I -m lH

L ayer 3 C h

19 1-n-1 P l

L ayer 4 M IA

1 1 1 - 1

1 -9

H

L ayer 4 R C L ayer 4 C h

I -a l

L ayer 5 1 4 . 1M

1 EH

1 000

100

1 200

1 300

1 400

P IH

L ayer 5 R C

1 2- 1

L ayer 5 C h

1 500

1 600

1 700

1 800

1 900

c a l R D

F igu re 7 . 5 . C a l ib ra ted p oo led m ean c ha rcoa l a nd ma r ine s he l l r a d ioca rbon d a te sf r om L aye r s 2t o 5a tK okohu ia . ( M M =s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; R C =s he l l c a l ib ra ted u s ing R e se rvo i r C o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa la ge ) .

7 0

CHAPTER 7

A na lys is o fR ad ioca rbon A ge s

T he v a r iab i l i ty i n t h e c ha r coa l c h rono logy a t K okohu ia , a f f ec t s t h e i n terp r e ta t ion o f p r eh is to r ic a c t iv i ty a tt h e s i te w hen t h e h i s to ry o f o ccupa t ion i s c on s ide red . When t h e p oo led m ean c ha r coa l a nd m a r ine s he l l d a tes f o ra l l a ye r s o f t h e s i te a r e s t a t i s t ica l ly c omb ined ( a s aC a se 2 s i tua t ion , s e e C hap te r2 ) , t h e c ha rcoa l a ge s a r e f ound t ob e d i s t ingu ishab le ( Tab le 7 . 6 ) . T he c ha rcoa l c h rono logy t h e ref o re i n d ica te s t h a t n o t a l t h e c u l tu r a l l a ye r s f r om t h e s i te w e re d epo s i ted a tt h e s ame t ime ( bu td oe s n o t r u le o u t c on t inua l o ccupa t ion o ve r a c e r ta in n umbe r o f y ea r s ) , w he rea s t h e m a r ine s he l l c h rono logy i mp l ie sn ob reak i na c t iv i ty . B y u nder tak ing a c l us te r a na ly s i s o n t h e p oo led m ean c ha r coa l d a te s f r om t h e s i t e ( f o l low ing aC a se 2 b i n s tance , s e e W i l son a nd Wa rd ( 198 1 :23 -26 ) ) , t empo ra l b r eak s i n o ccupa t ion m ay b ed e term ined .

r e se rvo i r c o r rec t ion m e thod . S econd , t h e mode l led m a r ine c urve c a l ib ra ted ' 4C d a te s a ppea r t ob e s l igh t ly y ounge r t h an r e se rvo i r c or ec ted c a l ib ra ted r a d ioca rbon d a te s . T he s p read i n a ge r a nge s f o r t h e r e se rvo i r c o r rec ted c a l ib ra ted s he l l d a te s , i sd ue t oc a l ib ra t ion o n t h e a tmo sphe r ic c urve w h ich r ef lec t s t empo ra l f l uc tua t ion s i n a tmo sphe r ic ' 4C c oncen t ra t ion . T he o l de r r e se rvo i r c o r rec ted c a l ib ra ted s he l l a ge s may b e d ue t ot h e u se o f af i xed R c o r rec t ion w h ich i s n o t a pp l icab le f o r t h i s p e r iod o f p r eh i s tory . I tc an a l so b e s e en t h a t s h e l l CRA s g r ea te r t h an 8 00 ± 4 0 y ea r s B P c a l ib ra ted u s ing b o th m a r ine c a l ib ra t ion m e thod s , a r e i n c l o se r a g reemen t i n t e rms o f c a l ib ra ted a ge r a nge , t h an c a l ib ra ted s h e l l d a te s l e s s t h an 7 90 ± 4 0 y ea r s B P . T h i s a ppea r s t ob e d ue t ot h e s moo the r n a tu r e o ft h e a tmo sphe r ic c a l ib ra t ion c ur ve b ef o r e 1 500 c a l AD . Ao tea

T he c l u s te r a na ly s is o n t h e p oo led m ean c ha r coa l a ge s i d en t if ie s t h a t t wo s ub -g roup s o f p oo led m ean a ge s a r e p r e sen t ( i nd ica ted b y ad rop i nt h e Av a lue f r om 9 . 1 t o5 . 2 ) ( Tab le 7 . 7 ) . T h i s i mp l ie s t h e r e w a s ab r eak i n o ccupa t ion b e tween L aye r s 4a nd 3i np r eh is to ry , a nd h ence t h e s i te w a s o ccup ied a t t wo d i f f e r ing p e r iod s . T he c a l ib ra ted p oo led m ean c ha rcoa l a nd ma r ine s he l l r a d ioca rbon d a te s f r om e ach l a ye r a tK okohu ia c onf i rm t h e o b se rva t ions f r om t h e c l us te r a na ly s is ( F igu re 7 . 5 ) . B a sed o n t h e a r chaeo log ica l e v idence f r om t h e s i te , w h ich i n d ica te sc on t inued a c t iv i ty ( s ee C hap te r 6 ) , t o ge the r w i th t h e a ppa ren t g rea te r r e p roduc ib i l i ty o ft h e m a r ine s he l l d a te s f r om e a ch l a ye r , t h e o ccupa t iona l h i s to ry a tK okohu ia i s mos t p robab ly r ef lec ted t h rough t h e m a r ine s h e l l c h rono logy . T h is , t h e ref o re , i n d ica te s t h a t t h e m a r ine s h e l l a ge s f r om K okohu ia mo r e c l o se ly r ef lec t a c tua l p r eh is to r ic b ehav iou r a t t h e s i te , t h an t h e c ha rcoa l c h rono logy d oe s .

A rea B ( S8 / 17 1 ) , L aye r 2( Tab le 7 . 8 ; F igure 7 . 6 ) A l l ma r ine s h e l l s pec ie s d a ted f r om L aye r 2o f A rea B , y i e lded s t a t i s t ica l ly i d en t ica l r e su l t s ( A(p ) =6 57 ± 2 3 ( T = 0 39 ;X 22 : 0 .0 5 =5 . 99 ) ) . O n ly o ne c ha r coa l r a d ioca rbon a ge w a s o b ta ined f r om t h i s s i te b ecause o f ap auc i ty o fc ha rcoa l r e t r ieved d u r ing e xcava t ion . When c a l ib ra ted , h oweve r , t h is c ha rcoa l r a d ioca rbon a ge i si na g reemen t w i th t h e c a l ib ra ted ma r ine s h e l l ' 4C d a te s( F igu re 7 . 6 ) .

T he c a l ib ra ted s he l l d a te s f r om t h is s i t e i l u s t ra te c l ea r ly t h e d i f f e rence s b e tween c a l ib ra t ing s he l l a ge s u s ing e i the r t h e r e servo i r c o r r ec t ion o r mode l led m a r ine c u rve m e thod s . Whe rea s t h e l a t te r p r ov ide s ac h rono logy w i th l e s s a ge r a nge , t h e f o rme r g i ve s a ge r a nge s w h ich s pan a g rea te r a moun t o f c a lenda r t i me ( F igu re 7 . 6 ) . T h i s s p read i n a ge r a nges i sd ue t o ' w igg le s ' i n t h e a tmo sphe r ic c a l ib ra t ion c u rve a f t e r c a . 1 500 c a l AD . T h i s e f f ec t i sa l so a ppa ren t i n t h e c a l ib ra ted c ha rcoa l r a d ioca rbon a ge . A rea B w a s b e l ieved b y t h e e xcava to r s t oh ave b een o ccup ied a r ound 2 50 y ea r s B P( s ee C hap te r6 ) . S he l l d a te s c a l ib ra ted u s ing t h e mode l led ma r ine c ur ve a r e m o re c on s i s ten t w i th t h e e xcava to r 's e s t ima te .

T he c a l ib ra ted c ha rcoa l r a d ioca rbon a ge s f r om e ach l a ye r a t K okohu ia a r e i na g reemen t w i th t h e i r c a l ib ra ted m a r ine s he l l p a i r s ( F igu re s 7 . 1 -7 . 4 ) . T h is s ugge s t s t h a t h a rd w a te r h a s n o t a f f ec ted t h e m a r ine s he l l a ges f r om t h i s s i te , d e sp i te t h e h i gh ly c a lca r eous g eo logy s u r round ing K okohu ia . Two d i f f e rence sb e tween t h et wo m a r ine s he l lc a l ib ra t ion m e thod s a r e a ppa ren t . F i r s t , t h e mode l led m a r ine c u rve o f t en p roduces a n a ge r ange f o r e ach c a l ib ra ted ma r ine s h e l l d a te , w h ich i sl e s s s p read o ve r t ime t h an t h a t p roduced b y t h e

L ab N o .

S amp le T ype

CRA

C a lA ge AD l a ( A tmo spher ic C urve )

Wk -3467

C ha r coa l

2 20 ±4 0

Wk -3678

P aph ie ss ub t r iangu la tum

6 60 ±4 0

Wk -3679

P aph ie sa u s t ra l i s

6 80 ±4 0

Wk -3680

A u s t rovenu ss t u tchbu ty i

6 30 ± 4 0

1 667 1 730 1 923 1 534 1 637 1 525 1 629 1 646 1 782 1 947

-1 690 -1 8 11 -1 954 -1 540 -1 662 -1 562 -1 654 -1 670 -1 798 -1 953

C a l A ge AD l a ( Mode l led Mar ine C urve )

1 6 10 -1 673 1 549 -1 663 1 642 -1 687

T ab le 7 . 8 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha r coa l a nd m a r ine s he l l f r om A rea B , L aye r 2 ,A o tea .

7 1

A na lys is o fR ad ioca rbon A ge s

CHAPTER 7

Wk-3680 MM

Wk-3679 MM

Wk-3678 MM

F l

H H

F a t ,

Wk-3680

R C

Wk-3679

R C

Wk-3678

R C

Wk-3467

C h

11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111Ill I

1 000

100

1 200

1 300

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1 500

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1 900

2 000

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2 200

c a l H D

F igu re 7 . 6 . C a l ib ra ted r a d ioca rbon a ge s f r om S i te B ( S8 / 17 1) , L aye r 2 , A o tea . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C urve ; R C =s he l l c a l ib ra ted u s ing R e se rvo i r C o r r ec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

c a l ib ra ted c ha r coa l s amp le , w hen u s ing e i the r s he l l c a l ib ra t ion m e thod ( F igu re 7 . 7 ) . T he l owe r a ge r a nge o f Wk 3 58 1 c a l ib ra ted u s ing t h e mode l led m a r ine c urve , f a l l s j u s t o u t s ide t h e u ppe r a ge r a nge o f t h e c a l ib ra ted c ha r coa l r a d ioca rbon d a te ( Tab le 7 . 9 ) . B ecau se t h e a ge d i f f e rence i s o n ly b y 0 . 25a ( n ine r a d ioca rbon y ea r s ) , a nd t h e CRA i s s t a t is t ica l ly i n d is t ingu i shab le f r om o t he r m a r ine s he l l d e term ina t ion s f r om t h e s ame s t ra t ig raph ic h o r izon , t h is i s p robab ly n o t as i gn if ican t r e su l t . F o r t h i s s i te , t h en , t h e c a l ib ra ted s he l l a ge s o b ta ined u s ing t h e r e se rvo i r c o r rec t ion c a l ib ra t ion m e thod , a r e i n c l o se r a g reemen t w i th t h e c a l ib ra ted c ha rcoa l a ge , t h an t h e s he l l d a tes c a l ib ra ted u s ing t h e mode l led ma r ine c u rve , b u t a s o n ly o ne c ha r coa l r a d ioca rbon d a te w a s d e r ived f r om t h i s s i te , t h e s i gn if i cance o f t h is r e su l t i s h ampe red b y l owe r l e ve ls o f p r ec i s ion .

P on u i I s land T he ma in d i ff icu l ty i nr a d ioca rbon d a t ing t h e a r chaeo log ica l s i te s e xcava ted o n P onu i I s land , w a s o b ta in ing a dequa te a moun t s o f s ho r t l ived c ha rcoa l f r om e ach s i te . T he i s l and w a s d om ina ted b y a nc ien t k au r i -podoca rp -ha rdwood f o r e s t d u r ing o ccupa t ion , a nd s o s ho r t l ived s pec ie s w e re r a r e ly f ound i ns e cu re c u l tu ra l c on tex t s( Wa l lace p e r s . c omm . ) . S i te N43/ 1 ,L aye rD( Tab le 7 . 9 ; F igure 7 .7 ) D e sp i te t h e f a c tt h a t d a ted s he l lf i sh s p ec ie s c ame f r om r o cky s ho re , e s tua r ine a nd s andy b each e nv i ronmen t s , a l r a d ioca rbon a ge s a r e i ns t a t is t ica l a g r eemen t ( A(p ) =8 43 ± 2 0 ( T =0 . 55 ;

X 24 :0 .0 5

d e term ina t ion s e xcep t

L ab N o .

—7 . 8 1) ) . A l l c a l ib ra ted m a r ine s he l l o ne ,

a r e

i n a g reemen t w i th

t h e

S amp le T ype

CRA

NZ -7764

C ha r coa l

5 35 ±4 8

Wk -3578 Wk -3579 Wk -3580 Wk -358 1

P aph i e sa us t ra l i s A us t rov enu ss t u tchbu ty i V enerup i sl a rg i l l i er t i P erna c ana l icu lu s

8 40 8 50 8 60 8 20

±4 0 ±4 0 ±4 0 ±4 0

C a l A ge AD 1 a ( A tmo spher ic C urve ) 1 4 10 -1 442 1 428 -1 451 1 425 -1 447 1 4 19 -1 445 1 435 -1 486

C a l A ge AD 1 a ( Mode l led Mar ine C urve ) 1 44 1 1 436 1 431 1 45 1

-1 49 1 -1 485 -1 479 -1 506

T ab le 7 . 9 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha r coa l a nd m a r ine s he l l f r om N 43 / 1 , L aye r D , P onu i I s land .

7 2

A na lys is o fR ad ioca rbon Age s

CHAPTER 7

Wk-3581

MM

Wk-3580 MM Wk-3579 MM Wk-3578 MM

I n 1

Wk-3581

R C

Wk-3580 R C Wk-3579 R C

Ha l

Wk-3578

R C

N Z-7764

C h

1111111I II11111IIIIIII1IIIIIl iii III1IIIIII1II1II111III1IIIh u t IIIi 1111111111111IIIIIIIIIII

1 000

100

1 200

1 400

1 300

1 500

1 600

1 700

1 800

1 900

F igu r e 7 . 7 . C a l ib r a ted r a d ioca rbon a ge s f r om s i te N 43 / 1 , L aye r D , P onu i I s land . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC = s h e l l c a l ib ra ted u s ing R e se rvo i r C o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

Wk-3589 MM

Wk-3588 MM

H

I -c -I

Wk-3589 R C

1 a - 1

Wk-3588 R C

Wk-3587 C h

Wk-3586 C h

II1IIIIII1IIIIIIIII III1IIIIIIIIIIIIIIIIIIL I IIIIII11 111 1 _L 1 1 1 L I 1IIIIIIIIIL I 1I1 IIII1III IIII1I

1 000

100

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1 900

c a l R D

F igu re 7 . 8 . C a l ib ra ted r a d io ca rbon a ge s f r om s i te N 43 /333 , L aye r D , P onu i I s land . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C ur ve ; R C =s he l l c a l ib ra ted u s ing R e se rvo i r C o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

7 3

A na lys is o fR ad ioca rbon A ges

CHAPTER 7

L ab N o .

S amp le T ype

CRA

C a l A ge AD I r r ( A tmospher ic C urve )

Wk -3586

C ha rcoa l

4 10 ± 4 0

Wk -3587

C ha rcoa l

4 30 ± 4 0

Wk -3588 Wk -3589

P aph ies a us t ra l i s A us trovenus s t u tchbury i

8 90 ± 4 0 9 30 ± 4 0

1 449 1 558 1 443 1 59 1 1 4 10 1 332 1 394

-1 528 -1 631 -1 520 -1 623 -1 439 -1 342 -1 429

C a l A ge AD I r r ( Mode l led Mar ine C urve )

1 4 15 -1 46 1 1 392 -1 44 1

T ab le 7 . 10 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha r coa l a nd ma r ine s h e l l f r om N 43 /333 , L aye rD , P onu i I s land .

L ab N o .

S amp le T ype

CRA

Wk -3590

C ha rcoa l

6 20 ± 4 0

Wk -359 1

P aph ies a us tra l i s

9 20 ± 4 5

Wk -3592

A us trovenus s t u tchbury i

9 40 ± 4 0

Wk -3593 Wk -3594

P erna c ana l icu lus C rasso s trea g lomera ta

9 10 ± 4 0 9 00 ± 4 0

C a l A ge AD I r ( A tmo spher ic C urve ) 1 325 -1 353 1 360 -1 367 1 388 -1 4 13 1 333 -1 339 1 397 -1 434 1 330 -1 346 1 392 -1 425 1 406 -1 436 1 408 -1 437

C a l A ge AD I r ( Mode l led Mar ine C urve )

1 395 -1 448 1 38 1 -1 436 1 403 -1 450 1 409 -1 456

T ab le 7 . 11 . C onven t iona lr ad ioca rbon d a te sa nd c a l ib ra ted a ge s o nc ha r coa l a nd ma r ine s he l l f r om S i te 1 4 , L aye r D , P onu i I s land .

L ab N o .

S amp le T ype

CRA

Wk -3596 Wk -3597

C ha rcoa l P aph ies a us t ra l i s

4 70 ± 4 0 7 40 ± 4 0

Wk -3598

A us trovenus s t u tchbury i

8 20 ± 4 0

C a l A ge AD l a ( A tmo spher ic C urve ) 1 436 -1 487 1 477 -1 534 1 538 -1 637 1 435 -1 486

C a l A ge AD I r ( Mode l led Mar ine C urve ) 1 506 -1 605 1 450 -1 507

T ab le 7 . 12 . C onven t iona l r ad ioca rbon d a te sa nd c a l ib ra ted a ge so n c ha r coa l a nd ma r ine s he l l f r om S i te 2 7 , L aye r D , P onu i I s land .

S i te N43/ 333 ,L ayer D ( Tab le 7 . 10 ; F igu re 7 . 8 ) T he t wo s he l lf i sh s pec ie s d a ted f r om t h i s s i t e a r e s t a t is t ica l ly i n d i s t ingu i shab le ( A( p ) =9 10 ± 2 8 ( T =0 . 50 ; x21, 0 . 0 5

=

3 . 84 ) ) . T he c ha rcoa l CRAs a r e a l so i ns t a t i s t ica l a g reemen t ( A( p ) =4 20 ± 2 8 ( T =0 . 13 ; x21, 0 . 0 5

f r om d i f f e ren t s h e l lf i sh s pec ie s a tt h i s s i t e a r e a ccu ra te , t h en , b u t i n t e rm s o f c a l ib ra t ion , t h e mode l led m a r ine c u rve c a l ib ra t ion m e thod p roduce s t h e c l o se s t a ge r a nge s t ot h o se o b ta ined f r om t h ec a l ib ra ted c ha r coa l d a te s . S i te 1 4 ,L aye rD( Tab le 7 . 11 ; F igure 7 . 9 )

=3 . 84 ) ) . A ge r a nge s

f r om t h e mode l led m a r ine c urve c a l ib ra ted s h e l l d a tes a nd c a l ib ra ted c ha rcoa l r ad ioca rbon d a tes f r om t h i s l a ye r s how c l o se a g reemen t , a nd a ppea r t oc o r rec t ly d a te t h is d epo s i t a s e v idenced b yt h ep re sence o fa n A rcha ic D uf fI A a dze f ound i nt h e s i te ( s ee C hap te r6 )( F igu re 7 . 8 ) . T he a ge r a nge s o ft h e r e se rvo i r c o r rec ted c a l ib ra ted s he l l d a te s , h oweve r , f a l l o u t s ide t h e a ge r a nge s o f t h e c a l ib ra ted c ha r coa l d a te . A l though o ne o ft h e mode l led ma r ine c u rve c a l ib ra ted d a te s u ppe r a ge r a nge (Wk -3589 ) f a l ls j us t o u t s ide t h e m in imum a ge r a nge o ft h e o lde s t c a l ib ra ted c ha rcoa l r a d ioca rbon d a te (Wk -3587 ) , t h i s i s o n ly b y t wo r a d ioca rbon y ea r s . I n a dd i t ion , Wk -3589 i ss t a t is t ica l ly i n d is t ingu ishab le f r om i t s p a r tne red m a r ine s he l l a ge . Ma r ine s h e l l r a d ioca rbon a ge s

R ad ioca rbon a ge d e term ina t ion s o n m a r ine s h e l l f r om S i t e 1 4 a r e s t a t is t ica l ly i n d is t ingu ishab le ( A( p ) =9 17 ± 2 1 ( T= 0 . 55 ; x23, 0. 0 5

=7 . 8 1) ) . A l l m a r ine s he l l CRAs c a l ib ra t ed

u s ing b o th m a r ine s he l l c a l ib ra t ion m e thod s a r e i n c l o s e a g reemen t w i th t h e p a i red c a l ib ra ted c ha r coa l d a te . B ecau s e o ff l uc tua t ion s i nt h e a tmo sphe r ic c a l ib ra t ion c urve , t h ough , ma r ine s he l l r a d ioca rbon d a te s Wk -359 1 a nd Wk -3592 c a l ib ra ted u s ing t h e r e servo i r c o r rec t ion m e thod , h ave m o r e e x tens ive a ge r a nge s i nc ompa r i son t ot h o se o b ta ined u s ing t h e m ode l led m a r ine c urve ( F igu re 7 . 9 ) . T he c a l ib ra t ed c ha r coa l a ge a l so e xpe r ience s mu l t ip le a ge r a nge s . B o th ma r ine s he l l c a l ib ra t ion m e thod s , t h e r ef o re , a r e i n c l o s e a g reemen t i nd a t ing t h is a r chaeo log ica l d epo s i t .

7 4

A na lys is o fR ad ioca rbon Age s

CHAPTER 7

F ni

Wk-3594 MM

I n1

Wk-3593 MM

I °1

Wk-3592 M M Wk-3591 MM

Wk-3594 R C Wk-3593 R C Wk-3592 R C Wk-3591

1 1 ° 1 H P i

R C

Wk-3590 C h

I11111111111 I1 I 1 I I I L 1111 1 111 1 111 II I 1111111 I ll I I 111 11111111 11111111 I 111111111 I

1 000

100

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c a l A D

F igu r e 7 . 9 . C a l ib ra ted r ad ioca rbon a ges f r om S i te 1 4 , P onu i I s land . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ;R C =s he l lc a l ib ra ted u s ing R e se rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

1 1 3- 1

I

Wk-3598 M M

"I

Wk-3597 M M

P— I

I1 c L a iI -

Wk-3598 R C

" "I

Wk-3597 R C

1 1 3- 1

Wk-3596 C h

i t i t i t t i l lu it i ii i ih in i m i l i m il lu l l inui til i tu tu a itn m i l l t iu m il l t i t i ll it i l in i 1 000

100

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c a l R D

F igu r e7 . 10 . C a l ib ra ted r ad ioca rbon a ge sf r om S i te 2 7 , P onu i I s land . ( MM =s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC = s he l lc a l ib ra ted u s ing R ese rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

7 5

CHAPTER 7

A na lys is o fR ad ioca rbon A ges

S i te 2 7 , L ayer D ( Tab le 7 . 12 ; F igu re 7 . 10 ) B o th m a r ine s he l l s pec ie s a r e i na g reemen t f o r d a t ing t h i s p r eh i s to r ic e ven t ( A(p )

7 80 ± 2 8 ( T =2 . 00 ; X23 : 0 .05 =

3 . 84 ) ) . When t h e s he l l d a te s a r e c a l ib ra ted u s ing e i the r m a r ine s he l l c a l ib ra t ion m e thod , Wk -3597 c a l ib ra ted u s ing t h e mode l led m a r ine c u rve i so f f se t c ompa red t o i t s p a i red c ha rcoa l c a l ib ra ted a ge (Wk -3596 )( Tab le 7 . 12 ; F igu re 7 . 10 ) . A ga in , h oweve r , t h e d i f f e rence i ss ma l l , b y o n ly 0 . 5 a( 19 y ea r s ) . F o r t h is s i te , t h e ref o re , t h e r e se rvo i r c o r rec ted c a l ib ra ted s he l l d a te s a r e i n c l o se r a g reemen t w i th t h e c a l ib ra ted c ha rcoa l a ge , t h an s h e l l a ge s c a l ib ra ted u s ing t h e mode l led m a r ine c urve . L igar Bay

N25 / 26 , L aye r 4( T ab le 7 . 15 , F igure 7 . 13 )

S i te N25 / 95 , Middens 1 A nd 2 ( Tab le s 7 . 13 - 7 . 14 , 7 . 22 ; F igure s 7 . 11 -7 . 12 )

R ad ioca rbon d e te rm ina t ions o b ta ined f r om L aye r 4o f s i te N25 /26 s how t h a t t h e s pec ie s o f s he l lf i sh d a ted w a s n o t a v a r iab le o fi mpor tance i na f f ec t ing r e p roduc ib i l i ty : a l l r e su l t s a r e s t a t i s t ica l ly i n d i s t ingu i shab le r e ga rd le s s o fs p ec ie s ( A(p ) =7 42 ± 1 8 ( T =1 . 55 ; x24 : 0 .0 5 =9 . 49 ) ) . B o th m a r ine s he l l

B ecau se b o th o ft h e se m iddens w e r ec l o se t oo ne a no the ra nd s t ra t ig raph ica l ly r e la ted , t h ey a r e a s sumed t o b e c on tempo ra ry a nd a r e d i scu s sed t o ge the rh e re . B o th m idden s s how c l o se a g reemen t b e tween r a d ioca rbon d e te rm ina t ion s f r om a l l s he l lf i sh s pec ie s( A(p ) =8 56 ± 1 4 ( T= 7 . 62 ; x27, 0 . 0 5 =1 4 .07 ) ) . F a s t d ecay r a te s o fd ead w ood a nd s ho r t l i f e s pan s o ft r ee s i nt h e a r ea , may h ave b een a n i nf luence o n t h e c l o se s im i la r i ty b e tween d a te s o f c ha rcoa l f r om t h e s i te ( A( p ) = 4 55 ± 2 8 ( T = 0 . 28 ; x21, 0 . 0 5

T he u ppe r c a l ib ra t ed a ge r ange o f s amp le Wk -3546 f r om M idden 2 c a l ib ra ted u s ing t h e r e se rvo i r c o r r ec t ion m e thod , f a l ls j u s t o u t s ide t h e c a l ib ra ted a ge r a nge o f i t s p a i r ed c ha rcoa l a ge Wk -3544 ( Tab le 7 . 14 ; F i gu re 7 . 12 ) . A ga in , t h i s d i f f e rence i sm in ima l ly s i gn if ican t ( t h ree r a d ioca rbon y ea r s s epa ra t ing t h e u ppe r a ge r a nge o f Wk -3546 , f r om t h e l owe r a ge r a nge o f t h e c a l ib ra ted c ha r coa l I 4C a ge (Wk -3544 ) ) . A lso , Wk -3546 i ss t a t i s t ica l ly i n d i s t ingu i shab le f r om o t he r ma r ine s h e l l d e te rm ina t ions f r om t h e s ame h o r izon . Wk 3 545 a nd Wk -3546 f r om m idden 2 e xh ib i t e x tended a ge r ange s w hen c a l ib ra ted u s ing t h e r e se rvo i r c o r rec t ion me thod . A ga in , t h e r e a son i s d ue t o ' w igg le s ' i n t h e a tmo sphe r ic c a l ib ra t ion c urve a tc a . 9 20 y ea r s B P , a nd 7 90 y ea r s B P .

= 3 . 84 ) ) ( s ee C hap te r 4 ) .

C er ta in ly , s ho r t l ived c ha r coa l w a s e a s ie r t oo b ta in f r om t h e L iga rB ay s i te st h an i tw a sa tK okohu ia a nd P onu i I s land . F o r b o th m iddens , t h e mode l led m a r ine c u rve c a l ib ra t ion m e thod p roduce s c a l ib ra ted a ge r a nge s w h ich a r e i n c l o se r a g reemen t w i th t h e a ge r a nge s f r om t h e c a l ib ra ted c ha rcoa l d a tes , t h an t h er e se rvo i rc o r r ec ted c a l ib ra ted s he l l d a tes .

L ab No .

S amp le T ype

CRA

Wk -3539

C ha rcoa l

4 40 ±4 0

Wk -3540 Wk -3541 Wk -3542 Wk -3543

P aph i es s ub tr iangu la tum P aph i es a us tra l i s A u s t rovenu ss t u tchbu iy i L une l la s maragda

8 80 8 20 8 40 8 70

±4 0 ±4 0 ±4 0 ±4 0

r ad ioca rbon a ge c a l ib ra t ion m e thod s p roduce r e su l t s i nc l o se a g reemen t w i th t h e p a i red c ha rcoa l c a l ib ra ted a g e . T he o n ly d i f f e rence b e tween b o th m a r ine s he l l c a l ib ra t ion m e thod s , i s t ha t s he l l d a te s c a l ib ra ted u s ing t h e mode l led m a r ine c u rve a r e l e s s s p read i n a ge r a nge s i n c ompa r i son t o t ho se c a l ib ra ted u s ing t h e r e servo i r c o r rec t ion m e thod , a nd p roduce a b e t te r ' f i t ' w i th t h e c a l ib ra ted c ha r coa l d a te ( F igu re 7 . 13) . T he c l o se a g reemen tb e tween t h e c ha rcoa l a nd ma r ine s he l l d e te rm ina t ions i sp robab ly d ue t ot h ed e l ibe ra te s e lec t ion o f c ha r coa l i d en t if ied t o t w ig s o f s ho r t l ived s pec ie s p r io rt od a t ing , a nd t h e h igh r a te o fd ecay o fw ood i n t h e l o ca l e nv i ronmen t( s ee C hap te r6 ) .

C a l Age AD l a ( A tmospher ic C urve ) 1 44 1 -1 50 1 1 5 10 -1 5 16 1 598 -1 6 18

C a l Age AD l a (Mode l led Mar ine Curve )

1 4 12 1 435 1 428 1 414

1 420 1 451 1 44 1 1 440

-1 441 -1 486 -1 451 -1 443

-1 467 -1 506 -1 49 1 -1 493

T ab le 7 . 13 . C onven t iona l r a d ioca rbon d a te sa nd c a l ib ra ted a ge s o n c ha rcoa l a nd m a r ine s he l l f r om M idden 1 ,s i t e N 25 /95 , L iga rB ay .

L ab N o .

S amp le T ype

CRA

C a l A ge AD l a ( Atmospher ic C urve ) 1 436 1 440 1 60 1 1 334 1 40 1 1 428 1 4 10

Wk -3544

C ha rcoa l

4 70 ±4 0

Wk 3 545

P aph ie ss ub tr iangu la tum

7 90 ± 4 0

Wk 3 546

P aph ie sa us tra l i s

9 20 ±4 0

Wk 3 547 Wk 3 548

A us t rovenus s t u tchbu ly i L une l la s maragda

8 40 ± 4 0 8 90 ± 4 0

-1 487 -1 495 -1 6 16 -1 337 -1 433 -1 451 -1 439

C a l Age AD l a (Mode l led Mar ine C urve ) 1 467 -1 528 1 398 -1 445 1 44 1 -1 49 1 1 4 15 -1 46 1

T ab le 7 . 14 . C onven t iona lr a d ioca rbon d a te sa nd c a l ib ra ted a ge so n c ha rcoa l a nd m a r ine s he l l f r om M idden 2 ,s i t e N 25 /95 , L iga rB ay .

7 6

A na lys is o fR ad ioca rbon A ge s

CHAPTER 7

I n— I

Wk-3543

M M

Wk-3542

M M

Wk-354 1

MM

Wk-3540

MM

Wk-3543

R C

Wk-3542

R C

Wk-3541

R C

Wk-3540 R C

H

H

1 11 11 1 1 1 1 1 1 1 11 11 1l i l i l i ll l IF l i tt iUI iI iiU1 111 1H ILL 1111 II1 1 000

100

1 200

1 300

1 400

1 500

1 600

Wk-3539

C h

1 1111II lilt I11111111IIIIII t 1 1

1 700

1 800

1 900

c a l R D

F igu re 7 . 11 . C a l ib ra ted r a d ioca rbon a ge s f r om s i te N 25 /95 , M idden 1 ,L iga r B ay . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC = s he l l c a l ib ra ted u s ing R e se rvo i r C o r r ec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

Wk-3549 M M Wk-3548

M M

Wk-3547 M M Wk-3546 M M

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

Wk-3545

M M

Wk-3549

R C

Wk-3548

R C

Wk-3547

R C

Wk-3546

R C

Wk-3545

R C

Wk-3544

C h

1 800

1 900

c a l R D

F igu re 7 . 12 . C a l ib r a ted r a d ioca rbon a ge s f r om s i te N 25 /95 , M idden 2 ,L iga r B ay . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C urve ; RC = s he l l c a l ib ra ted u s ing R e servo i r C o r r ec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

7 7

A na lys is o fR ad ioca rbon Ages

C II APTER 7

L ab N o .

S amp le T ype

CRA

C a l Age AD l a ( A tmospher ic C urve )

Wk -3533 Wk -3534

C ha rcoa l P aph ies s ub tr iangu la tum

3 90 ± 4 0

Wk -3535

P aph ies a us t ra l i s

7 60 ± 4 0

Wk -3536

A us trovenus s t u tchbury i

7 50 ± 4 0

Wk -3537

L une l la s maragda

7 60 ± 4 0

Wk -3538

C om ine l la a d sper sa

7 00 ± 4 0

1 482 1 477 1 538 1 448 1 56 1 1 45 1 1 554 1 448 1 56 1 1 50 1 1 5 17 1 620

7 40 ± 4 0

-1 638 -1 534 -1 637 -1 526 -1 629 -1 530 -1 633 -1 526 -1 629 -1 507 -1 597 -1 649

C a l A ge AD l a (Mode l led Mar ine Curve ) 1 500 -1 6 19 1 485 -1 560 1 492 -1 587 1 485 -1 560 1 530 -1 653

T ab le 7 . 15 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ges o n c ha rcoa l a nd m a r ine s he l l f r om s i te N 25 /26 , L aye r4 ,L iga rB ay .

L ab N o .

S amp le T ype

L ayer

CRA

Wk -4028

C ha rcoa l

L1 B

3 50 ±4 0

Wk -4033

L IB

8 30 ± 4 0

L IB

7 90 ± 4 0

NZ -770 1 i

P aph ie s a us tra l i s A us trovenus s t u tchbu ty i C ha rcoa l

L1 C

3 10 ± 10

Wk -4029

C ha rcoa l

L 1C

4 10 ± 4 0

Wk -3099

P aph ie s a us tra l i s L une l la s maragda

L 1C

8 00 ± 5 0

LI C

8 00 ±4 0

Wk -4030

Wk -4031

C a l A ge AD l a ( A tmospher ic C urve ) 1 519 -1 594 1 622 -1 650 1 432 -1 454 1 458 -1 479 1 44 1 -1 495 1 60 1 -1 6 16 1 447 -1 671 1 78 1 -1 799 1 945 -1 953 1 450 -1 528 1 558 -1 631 1 437 -1 495 1 60 1 -1 6 16 1 439 -1 492

C a l Age AD l a (Mode l led Mar ine C urve )

1 446 -1 498 1 467 -1 528

1 457 -1 527 1 462 -1 520

T ab le 7 . 16 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ges o n c ha rcoa l a nd m a r ine s he l l f r om L aye r s L IB a nd LI C , S awp i t P o in t( N26 /2 14 ) , Awa roa .

T he r e se rvo i r c or rec ted c a l ib ra ted m a r ine s he l l ' 4C d a te s a r e i n a g reemen t w i th t h e mode l led m a r ine c a l ib ra ted r a d ioca rbon d a te s , b u t h ave g rea te r a ge r a nges , a nd a r e s l igh t ly o l de r t h an t h e c a l ib ra ted c ha rcoa l d a t e s , a nd mode l led m a r ine c urve c a l ib ra ted s h e l l d a te s . T he c l o sene s s o ft h e c a l ib ra ted c ha rcoa l a nd s he l l d a te s , s ugges t s t h a t t h e re i sl im i ted i n bu i l ta ge i nt h ec ha rcoa l f r om t h es i te , a sf o und a t t h e L iga rB ay s i te so nt h e s ame c oa s t l ine .

Awaroa S awp i tP o in t( N26/ 214 ) ( Tab le 7 . 16 ; F igure 7 . 14 ) R ad ioca rbon d e te rm ina t ions f r om L aye r s L IB a nd L IC c onf i rm B a rbe r 's ( p e r s . c omm . )s ugge s t ion t h a tt h e l a ye r s a r e c on tempo ra ry ( s ee C hap te r 6 ) . A l l m a r ine s h e l l r a d ioca rbon a ges a r e s t a t i s t ica l ly i n d is t ingu i shab le ( A( p ) =8 05 ± 2 1 ( T= 0 . 56 ; x23, 0 . 0 5

=7 . 8 1) ) , a sa r e t h e c ha r coa l d a te s ( A( p ) =3 76

±2 7 ( T=

;X22 : 0 .0 5

1. 5 0

59 9

) .

7 8

A na lys is o fR ad ioca rbon A ge s

C lIAPTER 7

Wk-3538

MM

Wk-3537

MM

Wk-3536

MM

Wk-3535

MM

Wk-3534 MM

n

I"

n I

Wk-3538

R C

Wk-3537

R C

Wk-3536

R C

Wk-3535

R C

Wk-3534

R C

Wk-3533

C h

1 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

c a l A D

F igu r e 7 . 13 . C a l ib ra ted r a d ioca rbon a ges f r om s i te N 25 /26 , L iga r B ay . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C urve ; R C =s he l l c a l ib ra ted u s ing R e servo i rC o r r ec t ion m e thod ; C h =c a l ib ra ted c ha rcoa l a ge ) .

Wk-4033 MM Wk-4030 MM Wk-4031 MM Wk-3099 MM

MH

Wk-4033 R C

H

Wk-4030 R C

P— I

Wk-4031

R C

Wk-3099 R C

Wk-4028 C h Wk-4029 C h

I — n1 I —m 1 n

I

H

I

N Z-7701i C h

I1 111111111111111111111111 d111 1 1111111t1I LIII 1 11111 1 I1 1 11111111 h1 1 11111111 1 l it 111111111111111 111111iIIIIIIIIII

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

2 000

2 100

2 200

c a l R D

F igu re 7 . 14 . C a l ib r a ted r a d ioca rbon a ge s f r om S awp i t P o in t ( N26 /2 14 ) , L aye r s L IB a nd L1 C , Awa roa . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; R C =s he l l c a l ib ra ted u s ing R e se r vo i r C or rec t ion me thod ; C h = c a l ib ra ted c ha r coa la ge ) .

7 9

A na lys is o fR ad ioca rbon A ges

CHAPTER 7

ARCHAEOLOG ICAL S ITES WITH NO CHARCOAL / MAR INE SHELL CHRONOLOGICAL AGREE MENT F ive a r chaeo log ica l s i te s y i e lded c a l ib ra ted c ha rcoa l a nd m a r ine s he l l r ad ioca rbon a ges w h ich w e re i nd i sag reemen t , r ega rd le s s o f w h ich m a r ine s he l l c a l ib ra t ion m e thod w a s u sed ( Tab le s 7 . 17 -7 . 2 1 ; F igure s 7 . 15 -7 . 20 ) . T he mo s t l i ke ly r e a son s f o r t h e o b se rved d i f f e r ence s i n r a d ioca rbon a ge b e tween t h e se s amp le t ype s f o re ach o ft h e a f f ec ted s i te s a r ed i scu s sed b e low . I nbu i lt Age S i te N43/ 333 ,L aye rB , P onu iI s land L aye r Bo fs i te N 43 /333 s hows t h a t t h e c a l ib ra ted c ha rcoa l r ad ioca rbon a ge f r om t h is a r chaeo log ica l d epo s i t i s s i gn if ican t ly o lde r t h an t h e c a l ib ra ted m a r ine s he l l r ad ioca rbon a ge s f r om t h e i d en t ica l c u l tu ra l l a ye r ( Tab le 7 . 17 ; F igu r e 7 . 15 ) . L aye r D ( s t ra t ig raph ica l ly b e low L aye r

L ab N o .

S amp le T ype

B ) o fs i t e N 43 /333 ( s ee T ab le 7 . 10 a nd F igu re 7 . 8 ) , s howed a g reemen t b e tween i t s c a l ib ra ted m a r ine s he l l a nd c ha rcoa l r ad ioca rbon a ge s , a nd i n d ica ted t h a t t h e s i te w a s o ccup ied c a . 4 00 y ea r s B P . H oweve r , L aye r Bi sw e l l s epa ra ted f r om L aye r D a nd n ea r t h e s u rf ace o f t h e s i te i mp ly ing mo r e r e cen t d epo s i t ion . G iven t h e c l o sene s s o f t h e m a r ine s he l l a nd c ha r coa l r a d ioca rbon a ge s f r om L aye r Do ft h i s s i te , t h e c ha rcoa l /ma r ine s he l l p a ired r a d ioca rbon d a te s f r om o t he r a r chaeo log ica l s i te s o n t h e i s land , a nd f r om o t he r l o ca t ion s a round t h e c oun t ry , i n bu i l t a ge i sp robab ly o ne e xp lana t ion f o r t h e a noma lous c ha r coa l a ge f r om L aye r B . I t w a s i lu s t ra ted a t t h e K okohu ia s i te t h a t r a d ioca rbon d a te s o n t w ig c ha rcoa l f r om t h e s ame d epo s i t c an v a ry m a rked ly , p o s s ib ly d ue t oi n bu i l t a ge . I ta ppea r s , t h en , t h a tt h e c ha rcoa l d a ted f r om L aye r B may h ave c on ta ined e i the r t w ig w ood w h ich h ad s u r v ived i nt h e e nv i ronmen t f o r ag r ea t p e r iod o f t ime , o r m i s iden t if ied t w ig m a te r ia l , w h ich a c tua l ly c on ta ined b ranch wood r e p re sen t ing m any y ea r s o fg row th , o rl o ng d ead h ea r tw ood .

CRA

C a l A ge AD l a ( A tmospher ic C urve )

Wk -3582

C ha rcoa l

4 00 ± 4 0

1 453 -1 46 1 1 47 1 -1 532 1 546 -1 635

Wk -3583

P aph ies a us t ra l i s

5 90 ± 5 0

Wk -3584

A us t rovenu ss t u tchbury i

5 20 ± 4 0

Wk -3585

C rasso s trea g lomera ta

5 20 ± 4 0

1 654 1 733 1 931 1 678 1 804 1 909 1 954 1 678 1 804 1 909 1 954

-1 684 -1 808 -1 954 -1 775 -1 89 1 -1 939 -1 955* -1 775 -1 89 1 -1 939 -1 955*

C a l A ge AD l a ( Mode l led Mar ine C urve )

1 660 -1 7 19

1 706 -1 827

1 706 -1 827

T ab le 7 . 17 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha r coa l a nd ma r ine s he l l f r om s i te N 43 /333 , L aye rB ,P onu i i s land . ( *d eno te s i nf luence o fb omb C 14 , s e e S t u ive ra nd R e ime r( 1993) ) .

L ab No .

S amp le T ype

CRA

C a l A ge AD l a

C a l Age AD

( A tmo spher ic C urve ) MODERN

i r r (Mode l led Mar ine C urve )

1 479 1 643 1 784 1 950 1 681 1 806 1 906 1 954 1 665 1 731 1 925

1 50 1 -1 652 1 642 -1 678

Wk -3463

C ha rcoa l

MODERN^

Wk -3464 Wk -3465

P aph ies s ub tr iangu la tum P aph ies a us tra l i s

7 20 ± 6 0 6 40 ± 3 0

Wk -3466 1

A us trovenus s t u tchbu ry i

5 10 ± 4 0

Wk -3466 -2

A us trovenus s t u tchbury i

5 70 ± 4 0

-1 649 -1 668 -1 796 -1 952 -1 739 -1 901 -1 936 -1 955* -1 688 -1 8 10 -1 954

1 705 -1 854

1 675 -1 735

T ab le 7 . 18 . C onven t iona l r a d ioca rbon d a te sa nd c a l ib ra ted a ge s o nc ha r coa la nd ma r ine s he l l f r om A r ea A , L aye r 2 ,A o tea . ( At hough Wk -3463 i s MODERN , t h e CRA o f 1 98 ± 4 0 h a s b een c a l ib ra ted i nf i gu re 7 . 16 t oi l u s t ra te t h ed i f f e rence sb e tween c a l ib ra t ing y oung c ha rcoa l CRA u s ing t h e a tmo sphe r ic c a l ib ra t ion c urve , a nd c a l ib ra t ing y oung s he l l CRA u s ing t h em ode l led m a r ine c u rve . )

8 0

A na lys is o fR ad ioca rbon Age s

CHAPTER 7

n

Wk-3585 M M

n

Wk-3584 M M Wk-3583 M M

Wk-3585 R C

I n

n

I 9

H I—a11

1 000

100

1 200

1 300

1 400

1 500

Wk-3584 R C

I — c u l l

W k-3583 R C

nn

1 600

Wk-3582 C h

1 700

1 800

1 900

2 000

2 100

c a l R D F igu r e 7 . 15 . C a l ib ra ted r a d ioca rbon a ge s f r om s i te N 43 /333 , L aye r B , P onu i I s land . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; R C =s he l l c a l ib ra ted u s ing R eservo i r C or rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

I — a— I

W k-3466-2 M M

1 9-1 1 11 9 I nn

ni

p al p i _H

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

W k-34661

M M

W k-3465

M M

W k-3464

M M

W k-3466-2

R C

W k-34661

R C

W k-3465

R C

W k-3464

R C

W k-3463

C h

2 000

2 100

2 200

c a l H D F igu r e 7 . 16 . C a l ib ra ted r a d ioca rbon a ge s f r om A rea A ( S8 / 17 1) , L aye r 2 ,A o tea . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; RC = s he l l c a l ib ra ted u s ing R ese rvo i r C o r rec t ion m e thod ; C h =c a l ib ra ted c ha rcoa l a ge ) .

8 1

C l IAPTER 7

A na lys is o fR ad ioca rbon Ages

L ab N o .

S amp le T ype

CRA

Wk -3468

C ha rcoa l

2 20 ± 4 0

Wk -347 1 Wk -3470 Wk -3469

P aph ies s ub tr iangu la tum P aph ies a us tra l i s A us trovenus s t u tchbu ty i

7 30 ± 5 0 7 30 ± 4 0 8 20 + 4 0

C a l A ge AD l a ( A tmospher ic C urve ) 1 667 -1 690 1 730 -1 8 11 1 923 -1 954

Ca l A ge AD l a (Mode l led Mar ine Curve )

1 479 -1 643 1 486 -1 640 1 435 -1 486

1 50 1 -1 6 39 1 508 -1 6 32 1 451 -1 506

T ab le 7 . 19 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd ma r ine s h e l l f r om A rea C ( S8 / 16 ) , L aye r2 ,A o tea .

Wk-3469 M M

Wk-3470 M M

Wk-3471 M M

Wk-3469 R C

P— I n

Wk-3470 R C

" "I

Wk-3471

p u p Wk-3468 C h

H 1111 II I I I ll I I i ll I I II

1 000

100

1 200

11111111 I

1 300

1 400

I I II 1111 I I II I

1 500

1 600

R C

I ll 1 I II I I l l I I 1 1111 I II I 1111 11111111 I

1 700

1 800

1 900

2 000

2 100

c a l H D

F igu re 7 . 17 . C a l ib ra ted r a d ioca rbon a ge s f r om A r ea C ( S8 / 16 ) , L aye r 2 , A o tea . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC = s he l l c a l ib ra ted u s ing R e se rvo i r C o r rec t ion m e thod ; C h =c a l ib ra t ed c ha rcoa l a ge ) .

P os t Depos i t iona l D is turbance : H is tor ic a nd P reh is tor ic A rea A , L ayer 2 ( S8 / 17 1 ) a nd A rea C , L aye r 2( S8 / 16 ) , A o tea R ad ioca rbon a noma l ie s f r om A rea s A ( S8 / 17 1) a nd C ( S8 / 16 ) a t A o tea a r e p robab ly a t t r ibu tab le t o p o s t d epo s i t iona l d i s tu rbance ( Tab le s 7 . 18 -7 . 19 ; F i gu re s 7 . 16 7 . 17 ) . A r ea A w a s d i s tu rbed b y p lough ing a nd b u i ld ing a c t iv i t ie s i nh i s to r ic t ime s ( G rey 1 994 :5 ; M cGh ie 1 994 :29 ) . T he m a r ine s he l l r a d ioca rbon a ge s f r om L aye r 2 m ay r e p re sen t r epea ted o ccupa t ions o f t h e s i t e i n p r eh i s to ry t h rough t ot h e mode rn e r a( Tab le 7 . 18 ; F igu r e 7 . 16 ) . A tA rea C , t h e m a r ine s he l l r ad ioca rbon r e su l t s a r e o l de r t h an t h e c ha r coa l d e te rm ina t ion f r om a n i d en t ica l c on tex t ( Tab le

7 . 19 ; F i gu re 7 . 17 ) . T h is i s p robab ly b ecause o f p o s t d epo s i t iona l r ewo rk ing o f s he l l m idden f r om a p r ev ious o ccupa t ion o n t h e l i v ing t e r race . I t a ppea r s t h a t t h e i n hab i tan t s o fA rea C l e ve l led t h e t e r ra ce u s ing m idden f r om a n e a r l ie r o ccupa t ion , t hus t he d a ted s amp le s may n o t d a te t h eA rea C o ccupa t ion a ccu ra te ly ( C lough p e r s . c omm .2 6) . Mix ing o f Na tura l a nd Cu ltura l Ma ter ia l A t t wo a r chaeo log ica l s i te s , t he re a ppea r s t o h ave b een m ix ing o f n a tu ra l m a r ine s he l l d epo s i t s w i th c u l tura l m a te r ia l . T h is c au sed t h e s he l l d a te s t ob ee xces s ive ly o l d i n c ompa r i son t ot h e c ha rcoa l d a tes . T he a f f ec ted s i te s a r e S i te 9 5 o n P onu i I s land , a nd S awp i t P o in t( N26 /2 14 ) , Awa roa .

2 6

8 2

D r . R .C lough ,D epa r tmen to fA n th ropo logy ,U n ive r s i ty o fA u ck land .

A na lys is o fR ad ioca rbon A ges

L ab N o .

Wk -3599 Wk -3600 Wk -360 1

CHAPTER 7

S amp le T ype

C ha rcoa l A us trovenus s t u tchbu ty i C ha rcoa l

L ayer

CRA

B B

MODERN— 7 70 ±4 0

D

6 00 ±4 5

Wk -3602 1

A us trovenus s t u tchbu ty i

D

1 560 ±4 0

Wk -3602 -2

A us trovenus s t u tchbu ry i

D

1 480 ± 5 0

C a l Age AD l a ( A tmospher ic C urve ) MODERN 1 445 -1 522 1 583 -1 625 1 329 -1 349 1 39 1 •1 425 7 80 -7 91 8 03 -8 53 8 57 -8 99 9 19 -9 77 8 95 -9 24 9 40 -9 99 1 013 -1 0 16

C a l A ge AD l a (Mar ine C urve )

1 479-1545

7 74-877

8 62 -9 75

T ab le 7 . 20 . C onven t iona l r a d ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd m a r ine s h e l l f r om S i te 9 5 , L aye r s Ba nd D , P onu i I s land . ( — though Wk -3599 i s MODERN , t h e CRA o f 1 87 ± 4 0 h a s b een c a l ib ra ted i n f i gu r e 7 . 18 t o i l u s t ra te t h e d i f f e rence s b e tween c a l ib ra t ing c ha rcoa l CRA u s ing t h e a tmo sphe r ic c a l ib ra t ion c u rve ,a nd c a l ib ra t ing s he l l CRA u s ing t h e mode l led m a r ine c urve . ) .

1 000

1 100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

2 000

2 100

c a l R D

F i gu re 7 . 18 . C a l ib ra ted r a d io ca rbon a ge s f r om S i te 9 5 , L aye r B , P onu i I s land . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; R C =s he l l c a l ib ra ted u s ing R e se rvo i r C or rec t ion m e thod ; C h =c a l ib ra ted c ha rcoa l a ge ) .

8 3

A na lys is o fR ad ioca rbon Ages

CHAPTER 7

Wk-3602-2 M M

I

n

Wk-3602-1 M M

Wk-3602-2 R C

H

1 Wk-3602-1

R C

Wk-3601

C h

H1 - 1 1 1 1 -- 1

H 1 11

1 111 111 11 111 111 11 111 111 11 111 111 11 111 111 11 111 111 111 11 111 111 11 111 111 11 111 111 11 111 111 111 11 111 11 111 111 111 11 111 111 11 111 111 11 111 111 11 11 H 11 11 111 111 11

5 00

6 00

7 00

8 00

9 00

1 000 100 1 200 1 300 1 400 1 500 1 600 1 700 1 800 1 900 c a l A D

F i gu re 7 . 19 . C a l ib ra ted r a d ioca rbon a ge s f r om S i te 9 5 , L aye r D , P onu i I s land . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; RC = s he l l c a l ib ra ted u s ing R e se rvo i r C or r ec t ion me thod ; C h =c a l ib r a t ed c ha r coa l a ge ) .

e xp lo i ted b y t h e p reh is to r ic o ccupan t s , j udg ing b y t h e s pec t rum o f s he l l m idden r e f use a tn ea rby s i te s . F i nd ing a m idden c on ta in ing o n ly o ne s he l lf i sh s p ec ie s w a s t h e r ef o re u nu sua l . T he l o ca t ion o ft h e s i te d i rec t ly o n ab each f r on ta nd s t i l l w i th in t h e h i gh t i de m a rk c ou ld , i nh i nd s igh t , b e s e en a s ac l ue t ha t t h e d epo s i t s m ay b e p rone t ot h e i n co rpo r a t ion o f n a tu ra l s he l l . N e i the r h a rd w a ter e f f ec t s o r u pwe l l ing a r e v a r iab les w h ich c ou ld s e rve t o a f f ec t s h e l l a ge s i n t h is r eg ion .

S i te 9 5 ,L aye r s Ba nd D , P onu iI s land T he u nu sua l n a tu r e o ft h e m idden m a t r ix i nb o th L aye r s B a nd D a tS i te 9 5 s ugge s ted t ot h e e xcava to r st h a t s ome o ft h e s he l l r ema in s m ay h ave b een d epo s i ted n a tu ra l ly ( s ee C hap te r 6 ) . T he p r e sence o f as i ng le s he l lf ish s pec ie s i nt h e l a ye r s s e t t h i s c u l tu ra l l a ye r a pa r t f r om o t he r s o n t h e i s l and , a s a l o t he r c u l tu ra l d epo s i t s c on ta ined a w ide v a r ie ty o f s pec ie s . R ad ioca rbon d a t ing o f L aye r s Ba nd D a tS i te 9 5 c onf i rmed t h a t t h e m a r ine s he l l d epo s i t o f A u s t rovenu s s t u tchbu ty i (Wk -3600 , Wk -3602 1 , Wk -3602 -2 ) w a s m uch o lde r t h an o t he r n ea rby s i te s , a nd t h e ref o re p robab ly n o t c u l tu ra l ( Tab le 7 . 20 ; F igu res 7 . 18 - 7 . 19 ) . B o th c u l tu ra l l a ye r s s how am a rked d i sc repancy b e tween c a l ib ra ted s he l l a nd c ha r coa l d a te s . T hough t h e L aye r Bc a l ib ra ted s he l l a ge d oe s f a l l w i th in t h e a ccep ted t ime f o r h uman p r e sence o n P onu i , t h e d i sc repancy b e tween t h i s a ge a nd t h e c ha rcoa l d a te i sv ery l a rge . T he d ep th o f L aye r B b e low g round s u rf a ce ( s ee C hap te r 6 ) , i mp l ie s o ccupa t ion w i th in t h e l a s t 2 50 y ea r s , a si n d ica ted b y o t he r s i te s o n P onu i s uch a sL aye r Ba ts i te N 43 /333 . A l so ,t h e s im i la r i ty o f ma t r ice s o fL aye rB a nd L aye r D , a nd t h e s im i la r c ha rcoa l /ma r ine s he l l a ge d i sc repanc ie s , i mp ly t h a t as im i la r p roce ss h a s a f f ec ted t h e c h rono logy o fb o th s i te s . I ti sl i ke ly t ha t n a tu ra l b each s he l l w a s m ixed w i th c ha rcoa l a nd h ang i s t one s o fc u l tu ra l o r ig in f r om s ub sequen t h uman o ccupa t ion i n b o th l a ye r s , a s o r ig ina l ly b e l ieved b y t h e e xcava to r s ( s ee C hap te r 6 ) . T h i s e xpe r ience mu s ts e rve a s ac au t iona ry n o te f o ra r chaeo log i s t s c hoo s ing s amp le s f o r r a d ioca rbon d a t ing . T he p a laeoenv i ronmen to fS i te 9 5 w a ss im i la rt ot h e r e s to fP onu i I s land . A t l e a s t f o u r s he l lf i sh s pec ie s c ou ld h ave b een

Ic ompa red as amp le o fA u s trovenu s s t u t chbu ty i s he l l s f r om S i te 9 5 , w i th A u s t rovenu s s t u tchbu ty i f r om o t he r p r eh i s to r ic s i te s d a ted o n t h e i s land , b u t c ou ld a s ce r ta in n o s i gn if i can t t a phonom ic d i f f e rence s . F l e s sa e t a l . ( 1 993 :28 1 ,284 ; 1994 ) h ave n o ted t h a t u s ing t a phonom ic i n d ica to r s t o d i s t ingu ish b e tween r e cen t a nd a nc ien t ma r ine s h e l l s i sv e ry d i ff i cu l t , b ecause p re se rva t ion d epend s g rea t ly o n t h e d epo s i t iona l e nv i ronmen t . B ecause o f t h e s he l te r ed b ay s o f t h e w e s tern s ho re o f P onu i I s land f r om w h ich a r cha eo log ica l s i te s w e re s amp led , d i s t ingu ish ing b e tween o ld b ea ch s h e l l a nd r e cen t ly d ead s he l lf i sh w ou ld b e d i ff icu l t . F l e s sa e ta l . ( 1993 :384 ) a l so f ound r a d ioca rbon a ge s r a ng ing f r om m odern t o3 569 y ea r s B P o n m a r ine s he l ls s amp led f r om t h e s u rf ace o f a b each f l a t , s ugge s t ing t h a t t h e i n corpo ra t ion o fn a tu ra l s h e l ls i n a r chaeo log ica l s i te s c an i nduce s i gn if i can t e r ro r s i n r a d ioca rbon d a t ing , b y h und red s o rt hou sand so fy ea r s . A t S i te 9 5 , t h e d a te o f o ccupa t ion o f L ay e r s Ba nd D a r e t h e r ef o re p robab ly r ep re sen ted mo s t a c cu ra te ly b y t h e c ha r coa l r ad ioca rbon a ge s .

8 4

A na lys is o fR ad ioca rbon Ages

CHAPTER 7

S awp i tP o in t( N26/ 214 ) , Awaroa

s t u tchbury is he l ls w e re r ounded g i v ing a n a ppea rance o fa ge , b u t o t he r s w e re o n ly p a r t ia l ly r ounded a nd f r e sh i n a ppea rance . B ecau se o ft h e c oa r se n a tu re o ft h eg r an i te s a nd s i nt h is l o ca t ion , w ea r a nd r o und ing o f m a r ine s he l ls w ou ld n o t n ece s sa r i ly i n d ica te s i gn if i can t t ime l a p sed s i nce d ea th . T he r a d ioca rbon d a te o n A u s t rovenus s t u t chbury i (Wk -4032 ) c onf i rmed B a rbe r 's ( 1994 ) a s ser t ion t h a t t h is s he l lf i sh s pec ie s i nt h e s i t ew a s p robab ly s ub -f o s s i l .

S ub -fo s s i l b ea ch s he l l a l so a f f ec ted t h e a c cu racy o f r a d ioca rbon d a t ing o fL aye r L 1C a tS awp i t P o in t (Wk -4032 ) ( Tab le 7 . 21 ; F i gu re 7 . 20 ) . B a rbe r ( 1994 ) b e l ieved t h a t s ome o ft h eA u s t rovenu ss t u tchbury i f r om t h is l a ye rw a s s ub -f o s s i l ( s ee C hap t e r 6 ) , b u t d e term in ing w h ich A u s t rovenu s s t u tchbury i w a s s ub -f o s s i l , a nd w h ich w e re c u l tu ra l o n t a phonom ic g r ounds w a s d i ff icu l t . S ome o ft h e A u s t rovenu s

L ab N o .

S amp le T ype

L ayer

CRA

Wk -4028

C ha rcoa l

L IB

3 50 ± 4 0

Wk -4033

P aph ies a us tra l i s

L IB

8 30 ± 4 0

Wk -4030

L IB

7 90 ± 4 0

NZ -770 1i

A us trovenus s t u tchbu ry i C ha rcoa l

L 1C

3 10 ± 10

Wk -4029

C ha rcoa l

L 1C

4 10 ± 4 0

Wk -3099

P aph ies a us tra l i s

LIC

8 00 ± 5 0

Wk -4032

A us trovenus s t u tchbu ry i L une l la s maragda

L 1C L 1C

Wk -4031

C a l A ge AD l a ( Mar ine Curve )

1 870 ± 5 0

C a l A ge AD I c y ( A tmo spher ic C urve ) 1 519 -1 594 1 622 -1 650 1 432 -1 454 1 458 -1 479 1 44 1 -1 495 1 60 1 -1 6 16 1 447 -1 67 1 1 78 1 -1 799 1 945 -1 953 1 450 -1 528 1 558 -1 631 1 437 -1 495 1 60 1 -1 6 16 5 4 1 -6 42

8 00 ± 4 0

1 439 -1 492

1 462 -1 520

1 446 -1 498 1 467 -1 528

1 457 -1 527 4 53 -5 93

T ab le 7 . 2 1 . C onven t iona l r ad ioca rbon d a te s a nd c a l ib ra ted a ge s o n c ha rcoa l a nd ma r ine s h e l l f r om s i te N 26 /214 , L aye r s L1 Ba nd LI C , S awp i t P o in t , Awa roa .

Wk-4033 M M

I n 1

Wk-4030 M M Wk-4032 M M Wk-4031 M M

l n 1

Wk-3099 MM

r i

Wk-4033 R C

H

Wk-4030 R C Wk-4032 R C Wk-4031

H

R C

Wk-3099 R C Wk-4028 C h Wk-4029 C h

II

3 50

6 00

L 1 1

8 50

N Z-7701i C h

.

1 1 1 1 1

100

I

1 1 1

1 350

1 600

1 850

2 100

Ii 2 350

c a l O D

F igu r e 7 . 20 . C a l ib ra ted r a d ioca rbon a ge s f r om S awp i t P o in t ( N26 /2 14 ) , L aye r s L IB a nd L IC , Awa roa , s how ing i nf luence o n c h rono logy b y i n co rpo ra t ion o fs ub -f o s s i l s he l l (Wk -4032 ) . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C urve ; RC = s he l l c a l ib ra ted u s ing R e se rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha rcoa l a ge ) .

8 5

Ana lys is o fR ad ioca rbon Age s

C II APTER 7

s p ec ie s c ou ld h ave b een m is iden t if ied , a nd t h e s amp le s m ay h ave c on ta ined e i the rl o ng l ived w ood , o ro l d w ood .

S u m mary E ach o ft h e a r chaeo log ica l s i t e s e xpe r ienc ing a ge a noma l ie s d i scu s sed a bove , i l u s t ra te t h e r i sk s i n vo lved i nu s ing m a r ine s h e l l a nd c ha rcoa l f o r r a d ioca rbon d a t ing p r eh i s to r ic c on tex t s . T hey a l so e mpha s i s t h e i mpo r tance o fc on s ide r ing f a c to r s o u t s ide t h e r a d ioca rbon m e thod , e g . p o s t -depo s i t iona l d i s tu rbance . T he se s i tes m ay b e e xc luded f r om f u r the r a na ly s is o n t h e b a s is o f t h e r e a sons s e t o u t a bove , b u t t h e f a c to r sw h ich c au sed t h e i re xc lu s ion s hou ld b e c on s ide r ed b y a r chaeo log is t s w hen e ndeavou r ing t o d a te p r eh i s to r ic d epo s i t s .

S e lec t ing c ha rcoa l f r om t r ee a nd s h rub s pec ie s k nown t o h ave b een u sed o n ly w hen g reen b y p reh is to r ic M ao r i m ay b e as o lu t ion t o f u r the r r educ ing i n bu i l t a ge o f c ha rcoa l s amp le s . E xamp le s o ft h e se t r ee a nd s h rub s pec ie sa r e :

D ISCUSS ION AND CONCLUS IONS

•

Manuka , K anuka a nd K owha i u sed a s f i r ewood o r f o r m ak ing t o o ls ( C l if ton 1 990 :77 -78 ) ;

•

T awa a sf u e l , a sw e l l a ss ma l l g r een b ranche sf r om o the r s pec ie s b urn tt ok eep i n sec t sa way ( Tay lo r 1 9 94 :13 ) ;

•

Mana tu a nd R ibbonwood b a rk u sed f o rm ak ing s e ine n e t r ope s( Tay lo r 1 994 :13 ) ;

•

P u r i r i s e ed s f o rd ye s ( Tay lo r 1 994 :13) ;

•

M i ro , H inua a nd T awa e xp lo i ted f o r o i l a nd a s f ood s ou r ce s( Tay lo r 1 994 :13 ) ;

•

T ree a nd s h rub s pec ies u sed a s m ed ic ine s ( s ee R i ley 1 994 ) .

Rad iocarbon Da t ing o f Mar ine S he l l a nd Charcoa l T he c on s is tency i n r ad ioca rbon d a te s b e tween d i f f e r en t s h e l lf i sh s pec ie s i si mmed ia te ly a ppa ren t a f te r ap e ru sa l o f t h e s he l l a ge s f r om t h e a r chaeo log ica l s i t e s p re sen ted a bove ( Tab le s 7 . 1 -7 . 16 ; F igure s 7 . 1 -7 . 14 ) . T h i s s ugge s t s t h a tt h e s he l lf i sh s pec ie s P aph ie s a u s t ra l i s , A u s t rovenu s s t u tchbu ry i , P aph ie s s ub t r iangu la tum , L une I la s ma ragda , V ene rup i s l a rg i l l ie r t i , P e rna c ana l icu lu s , C ra s so s t rea g lome ra ta , C om ine l la a d spe r sa a nd C om ine l la v i rga ta a r e a l l r e l iab le a t t h i s l e ve l o fp r ec i s ion f o r r a d ioca rbon d a t ing N ew Z ea land p r eh is to r ic s i te s . I ta l so a ppea r s t h a t t h e h ab i ta t s a nd l i f e w ay s o f t h e se s pec ie s h ave n o t e f f ec ted a ccu racy . T ho se s he l lf i sh s pec ie s f r om o pen b each e nv i ronmen t s p r ov ided s im i la r r a d ioca rbon a ge s t o s p ec ie s f r om b o th r o cky s ho re a nd e s tua r ine e nv i ronmen t s( s ee C hap te r4 ) .

T he p r esence o ft h e se s pec ie s i n as i te w ou ld i n f e ri mmed ia te u se b y t h e p r eh i s to r ic i n hab i tan t s , t h u s i n bu i l t a g e m ay b e s i gn if ican t ly r e duced . T h is wou ld a l so m ean t h a t a r chaeo log i s t s m ay b e a b le t o a ccep t t w ig s f r om m ed ium t o l o ng l ived t r ee s pec ie s mo re o f ten f o rd a t ing .

I na dd i t ion , t h e c a lca reous c on ten t o fr o cks s ur round ing t h e a r chaeo log ica l s i te s d oe s n o t a ppea r t o h ave a f f ec ted r a d ioca rbon d a te s o f s he l lf i sh . E ven a t K okohu ia , w he re a h a rd w a te re f f ec tw a sc on s ide red as ou r ce f o re r ro r , n one w a s d e tec ted . Mu l t ip le c ha rcoa l r a d ioca rbon d a tes f r om an umbe r o fs i t e s u sed i nt h i s s t udy w e re a l so c ons is ten t , p r e sumab ly b ecau se t h e s amp les w e re r i go rou s ly i d en t if ied t ot w ig s o fs ho r t l ived s pec ie sp r io rt od a t ing . I ns ome i n s tance s , h oweve r , c ha r coa l a ge s f r om t h e s ame d epo s i t , d i d v a ry ma rked ly i n a ge b e tween t h e y ounge s t a nd o l de s t r a d ioca rbon d a t e ( s ee K okohu ia ) . S uch v a r ia t ion s o n c ha r coa l s amp le s f r om t h e s ame p rovenance c an m ean t h e d i f f e rence b e tween as i ng le c a l ib ra ted c ha rcoa l r ad ioca rbon d a te a g r ee ing o r d i sag r ee ing , w i th ap a i red c a l ib ra ted ma r ine s he l l d a te .

T he a na ly s i s o fp a i red ma r ine s he l l a nd c ha rcoa l r a d ioca rbon a ge s , s ugge s t s t h a t m a r ine s he l l w i l l y i e ld r e l iab le a nd c ons i s ten t r a d ioca rbon d e te rm ina t ions . C er ta in ly , t h ey s how g r ea te r r e p roduc ib i l i ty t h an c ha rcoa l . Whe rea s m u l t ip le c ha rcoa l r a d ioca rbon d a te s f r om t h e s ame s t r a t ig raph ic c on tex t c an s how v a r ia t ion , mu l t ip le m a r ine s he l l a ge s o n a v a r ie ty o fs h e l lf i sh s pec ie s a ppea r t op rov ide am u ch t i gh te r c h rono logy . T h is i s i mpo r tan t b ecau se i ts ugg e s t s t h a t a s i ng le m a r ine s h e l l r ad ioca rbon a ge w i l l r ef lec t t h e t i me a t w h ich ap r eh i s to r ic e ven t t o ok p l ace mo re a ccu ra t e ly t h an a s i ng le c ha r coa l r a d ioca rbon a ge . T he o n ly r i sk i d en t if ied i n t h i s t h e s is i n u s ing ma r ine s he l l t o r ad ioca rbon d a te a r chaeo log ica l s i t e s , i st h e i n co rpo ra t ion o fs he l l f r om n a tu ra l b each d epo s i t s . I nt h is s t udy , h oweve r , b o th s i te s w h ich w e re e f f ec ted b y n a tu ra l b each s he l l , S i te 9 5 o n P onu i I s l and a nd L aye r L 1C a tS awp i t P o in t , w e re i d en t if ied a s p r ob lema t ic p r io rt od a t ing . Co mpar ison o f Mar ine S he l l Ca l ibra t ion Me thods

T he v a r ia t ion i n m u l t ip le c ha rcoa l d e term ina t ion s c ou ld e i the r b e d ue t os t a t is t ica l v a r ia t ion o r i n bu i l t a ge . l ta ppea r s f r om t h i s a na ly s i s o fc ha rcoa l a nd ma r ine s he l l r a d io ca rbon d a te s ,t h a tt h ev a r ia t ions i nc ha r coa l a ge sa r e p robab ly d ue t o n on sy s tema t ic i n bu i l t a ge w h ich may o ccu r e ven i ns ho r t l i ved s pec ie s . A nde r son ( 199 1 :780 -78 1) h a s n o t ed t h a t c ha r coa l f r om t w ig s o fs hor t l ived s pec ie s may s t i l l r e ta in a n a ge o fu p t o5 0 t o 1 50 y ea r s o r g rea te r , a nd b o th A nde r son ( 199 1) a nd S imp son ( pe r s . c omm . ) h ave s ugge s ted t h a t t h e s peed o f d ecay i sr e la ted t o t h e l o ca l e nv i ronmen t a nd t o s pec ie s ( s ee C hap te r 4 ) . I ti sp o s s ib le , t h e ref o re , t h a t p a s t e nv i ronmen ta l c ond i t ions a t K okohu ia a nd P onu i I s land c ou ld h ave b rough ta bou ts l ow d ecay o fd ead wood , m ean ing t h a t s ome o ft h e w ood u sed b y t h e i n hab i tan t s a tK okohu ia a nd s i te N 43 /333 , L aye r Bo n P onu i I s land , c ou ld h ave b een p r e sen t i nt h e e nv i ronmen t f o r al o ng p e r iod o ft ime b ef o re u se . A l te rna t ive ly , c ha rcoa l i d en t if ied a st w ig s o fs ho r t l ived

T h is a na ly s i s f o und t h a t m a r ine s he l l CRAs c a l ib r a t ed u s ing t h e mode l led m a r ine c a l ib ra t ion c u rve , mo re o f t en a g reed w i th t h e p a i r ed c a l ib ra ted c ha rcoa l a ge , t h an s h e l l d a te s c a l ib ra ted u s ing t h e r e se rvo i r c o r rec t ion t e chn ique . T he r e se rvo i r c o r r ec t ed c a l ib ra t ions a ppea r ed i n s ome c a se s t oo o l d b y a pp rox ima te ly 2 0 y ea r s , c ompa r ed t o t h e m ode l led m a r ine c urve c a l ib ra t ions , a nd c a l ib ra ted c ha rcoa l d a te s . A dd i t iona l ly , t h e a ge r ange s a s soc ia ted w i th t h e m ode l led m a r ine c urve c a l ib ra t ions , mo re o f t en l a y w i th in t h e a ge r a nge so ft h ep a i red c a l ib ra ted c ha rcoa ld a tes . Whe the rt h e c a l ib ra ted a ge r a nges p roduced b y t h e m ode l led m a r ine c u rve r ef lec t t h e c h rono logy o f t h e a r cha eo log ica l s i te s c oncerned a ccu ra te ly , may o n ly b e e va lua ted b y c ons ide r ing t h e f o l low ing q ue s t ions :

8 6

A na lys is o fR ad ioca rbon Ages

CHAPTER 7

Mode l l ing C hange si nR ( t ) T hrough T ime

1 ) D oe st h e mode l led ma r ine c u rve s ucce s sf u l ly s imu la te c hange s i nR ( t )t h rough t i me? 2 )

D ot h e ' t igh t ' c a l ib ra ted a ge r a nge sp roduced b yt h e mode l led m a r ine c urve p r ov ide at r ue r ef l ec t ion o ft h e d a te o ft h ep r eh i s to r ic e ven ti nq ue s t ion ,b a sed o nt h e c a l ib ra ted c ha r coa l d a te s , r e se rvo i rc o r r ec ted c a l ib ra ted s he l ld a te s , a nd t h e a r chaeo log ica l e v idence?

C a l cu la t ing R ( t )a nd AR I n c on s ide r ing t h e se q ue s t ion s , t h e r e se rvo i r a ge s R ( t ) a nd A R v a lue s f o r e a ch o ft h e r a d ioca rbon d a t ed a r chaeo log ica l s i t e s a bove , h ave b een c a lcu la ted s o a st op r ov ide a dd i t iona l d a ta t ot h a ta l ready p r esen ted ( s ee C hap te r5 )( Tab le 7 . 22 ) . F o rf i ve a r chaeo log ica l d epo s i t s , mu l t ip le p o s s ib le AR v a lue s r e su l ted d u r ing c a lcu la t ion . T h i s i sb ecau se t h e S t u ive r a nd B raz iuna s( 1993 )c onve r s ion c u rve u sed t od e r ive amode l led m a r ine r a d ioca rbon a ge f r om ac ha rcoa l r a d ioca rbon a ge f o r A R c a lcu la t ion , i n co rpo ra te s o sc i l la t ion s i na tmo sphe r ic ' 4C t h rough t ime ( s ee C hap te r 5 ) . T h i s c au se s ' w igg le s ' t oo ccu r i nt h e c urve ( s ee F igu re 5 . 3 ) . H ence , s ome t ime s d u r ing t h e c onve r s ion o f as i ng le c ha r coa l r a d ioca rbon d a te t o a m ode l led ma r ine a ge , ' w igg le s ' i nt h e c onve r s ion c urve a r e e ncoun te red , p roduc ing mu l t ip le p o s s ib le m ode l led m a r ine a ge s . F o re xamp le ,t h e s i ng le c ha rcoa l r a d ioca rbon d a te f r om A rea B , A o tea , o f 2 20 ± 4 0 y ea r s B P , p roduce s t h ree p o s s ib le mode l led m a r ine a ge s : 6 50 ± 4 0 , 5 60 ± 4 0 a nd 4 70 +4 0y ea r sB P( s ee F igure 5 . 3 ) . T h is e qua te st ot h ree p o s s ib le AR v a lues o f 7±4 7 , 9 0 ±4 7 a nd 1 87 ± 4 7 y ea r s . B ecause i t i sd i ff i cu l t t o d e term ine w h ich AR v a lue i sa pp rop r ia te f o r t h e se s i te s , AR h ave b een c a lcu la ted o n ly f o r s i t e s w h ich d o n o te xpe r ience mu l t ip le AR v a lue s( Tab le 7 . 22 ) .

S i te

K okohu ia L aye r2 K okohu ia L aye r3 K okohu ia L aye r4 K okohu ia L aye r5 L iga rB ay N 26 /95 L iga rB ay N 25 /26 P onu i I s .N 43 / 1 P onu i I s .N 43 /333 P onu i I s . S i te 1 4 P onu i I s . S i te 2 7 S awp i tP o in t( N26 /2 14 ) A rea B ( S8 / 171) , A o tea P oo led Mean ( A( p ) )

P oo led m ean m a r ine s he l l CRA v e r su s p oo led m ean c ha r coa l CRA f o r e ach s i te i nt a b le 7 . 22 , h ave b een p l o t ted i nf i gu re 7 . 2 1 . T he se p lo t s i l us t ra te c hange i n R ( t ) t h rough t ime ( c a lcu la ted f o r e ach s i te i nt a b le 7 . 22 ) ( s ee C hap te r 5 ) . A lso p l o t ted i nf i gu re 7 . 2 1 , i st h e r e se rvo i rc or r ec t ion l i ne f o rN ew Z ea land ( R =3 85 ) ( s ee C hap te r 5 ) . When u s ing t h e r e se rvo ir c o r rec t ion c a l ib ra t ion m e thod , m a r ine s h e l l CRAs a r e a pp l ied t ot h is l i ne t oc onver t as he l l d a te i n to a n e qu iva len t t e r r e s t r ia l a ge , b ef o re c a l ib ra t ion o n t h e a tmo sphe r ic c a l ib ra t ion c urve . T he mode l led m a r ine c a l ib ra t ion c u rve f o r t h e p e r iod 2 00 t o7 00 y ea r s B P i sa l so s hown i nf i gu re 7 . 2 1 ( S tu ive r a nd B raz iuna s 1 993 :183 ) . I ti sa ppa r en t f r om f i gu re 7 . 2 1 , t h a t R ( t ) c an v a ry ma rked ly t h rough t i me ( No te : p l o t s m a rked * h ave o n ly o ne c ha r coa l a ge a va i lab le f o r R ( t ) c a lcu la t ion ) . H oweve r , a l though t h e m ode l led m a r ine c u rve d oe s a ppea r t os ucce s sf u l ly s imu la te t h e t empo ra l v a r iab i l i ty o f R ( t ) , t h e f i xed r e servo i r c o r rec t ion c an a l so b e s e en t o a ccoun t f o rt h is c hange . T h is o b se rva t ion i sc onf i rmed w hen ap o lynom ia l c urve o fo rde r 3( RA2 = 0 . 649 ) a nd as t ra igh t l i ne l i nea rr eg re s s ion ( RA2 = 0 . 642 ) a r e f i t ted t ot h e r e servo ir a ge d a ta ( F igu re 7 . 22 ) . When t h e se g r aph s a r e c ompa red w i th f i gu re 7 . 2 1 , t h ey i lu s t ra te t h a t n e i the r t h e f i xed r e se rvo i r c o r rec t ion o r mode l led m a r ine c u rve mo re s ucce s sf u l ly a ccoun t s f o r c hange i nR ( t ) t h rough t ime b a sed o n t h i sa na ly s is . O ne r e a son f o r t h e d i ff icu l ty i n a s ce r ta in ing w h ich c urve mo re s u cce s sf u l ly s imu la te s c hange i nR ( t ) t h rough t ime , i s t h e s ma l l n umbe r o fc ha rcoa l CRA f r om s ome s i te s . S i ng le c ha r coa l a ge s m ake i td i ff icu l t t op r ec i se ly c a lcu la te R ( t ) a s o ne a ge m ay n o t b e r e p resen ta t ive o ft h e r a nge o fd a te s f r om as i t e . T he d i f f e rence s b e tween e a ch m a r ine s he l l c a l ib ra t ion m e thod a r e o n ly a ppa ren t w hen m a r ine s h e l l a ge s a r e c a l ib ra ted u s ing b o th m e thod s( a ss e en i nt h e s i t es a bove ) ,

P oo led Mean C harcoa l CRA

P oo led Mar ine S he l l CRA

( A( P ) )* 3 70 ± 1 8 3 73 ±2 3 4 35 ±2 0 4 50 ± 1 7 4 55 ±2 8 3 90 ±4 0 5 35 ±4 8 4 20 ±2 8 6 20 ±4 0 4 70 ±4 0 3 76 ±2 7 2 20 ±4 0

( A( P ) )* 7 44 ± 1 8 7 34 ± 1 8 7 70 ±2 0 8 15 ± 1 9 8 56 ± 1 4 7 42 ± 1 8 8 43 ±2 0 9 10 ±2 8 9 17 ±2 1 7 80 ±2 8 8 05 ±2 1 6 57 ±2 3

R ( t )

3 74 3 6 1 3 35 3 65 4 0 1 3 52 3 08 4 90 2 97 3 10 4 29 4 37

AR v a lue

±2 5 ±2 9 ±2 8 ±2 5 ±3 1 ±4 4 ±5 2 ±4 0 ±4 5 ±4 9 ±3 4 ±4 6

80 ±2 8 4 5 ±2 5 4 ±3 1 77 ±5 2 6 0 ±4 0 6 3 ±4 5 1 10 ±4 9 _ .

3 67 ± 1 04

42± 2 5t

T ab le 7 . 22 . R e servo i r a ge s a nd AR v a lue s f o r a r chaeo log ica l s i te s d a ted i nt h is s t udy w i th a ccep tab le p a i r s o f c ha rcoa l a nd ma r ine s h e l l r ad ioca rbon d a te s . E ach s i te h a s h ad i t s mu l t ip le c ha r coa l a nd m a r ine s he l l c onven t iona lr a d ioca rbon a ge sp oo led ( A( p ) )b ef o re r e servo i rc o r rec t ion a nd AR v a lue s h ave b een c a lcu la ted . A l l p oo led a ge s a r e s t a t i s t ica l ly i n d i s t ingu i shab le . * = Wa rd a nd W i lson ( 1978 ) . X2 1 :0 .05 = 1 9 .68 . t=T e s ts t a t is t ic : T= 1 2 .46 ; x26 : 0 .0 5

4

=T e s t s t a t is t ic : T= 2 3 .0 1 ;

=1 2 .59 ( La rge s to fw e igh ted o ru nwe igh ted ' s ca t te r ' m ean

a g iven f o r f i na l p oo led m ean A R v a lue r ounded u p t o 5y ea r s a s r e commended b y S t u ive r e t a l . ( 1986 :982 ; 1993 :155 ) ) . S i te sn o ts how ing AR v a lue sa r ew he re m u l t ip le AR a r ep o s s ib le ( s ee a bove ) .

8 7

A na lys is o fR ad ioca rbon Age s

CHAPTER 7

w he r e t h e i nf luence o f t h e c a l ib ra t ion c u rves o n t h e s he l l d a te sc an b ec l ea r ly s e en ( s ee b e low ) .

p r e sen ted a bove , w he re t h e re i s a g reemen t b e tween t h e m ode l led m a r ine c urve c a l ib ra ted s he l l d a te s , a nd p a i red c a l ib ra ted c ha r coa l d a te s ,t h is h a s s hown t ob et h ec a se .

S ome o b serva t ions m ay b e m ade , h oweve r , w i th r ega rd t o t h i s d a ta . I tc an b es e en t h a tt h e R ( t ) v a lue s c a lcu la ted f o rt h e a r chaeo log ica l s i te s s amp led i n t h is s t udy a r e s t a t is t ica l ly d i s t ingu ishab le , p o s s ib ly i n d ica t ing t h a t af i xed r e servo i r c o r r ec t ion i s n o t a pp l icab le f o r a l o f t h e N ew Z ea land p r eh i s to r ic s e quence ( Tab le 7 . 22 ) . A lso , a pp l ica t ion o f t h e m ode l led m a r ine c urve c a l ib ra t ion m e thod f o r N ew Z ea land i s d ependen t o n t h e

l o ca l AR v a lue b e ing

n on

S imu la t ing Mar ine S he l l C a l ibra t ion b e tween C a l ibra ted Age R ange s

t ime -

d ependan t . T he AR v a lue o f 4 2 ±2 5 c a lcu la ted f o r t h e a r cha eo log ica l s i te s p r e sen ted i nt a b le 7 . 22 , i ss t a t is t ica l ly i n d i s t ingu ishab le f r om t h e c ur ren tv a lue o f25 ± 1 5 ( A(p ) =3 0 ± 1 3 ( T =0 . 73 ; Y 2( : 0 .05 = 3 . 84 ) ) ( H igham a nd H ogg 1 995 ) . T h is i n d ica te s t h a t t h e re h a s b een n o t empo ra l v a r ia t ion i n AR o ve rt h ep a s t 7 00 y ea r s f o rN ew Z ea land , a nd t h a t u se o f t h e H igham a nd H ogg ( 1995 ) AR v a lue i n a s soc ia t ion w i th t h e mode l led m a r ine c urve , s hou ld s u cce s sf u l ly c a l ib ra te m a r ine s he l l CRA s . F rom t h e s i te s

100 -

Mar ine S he l l CRA

.

M cFadgen e ta l . ( 1994 ) h ave i l u s t ra ted t ha t ' w igg le s ' i nt h e a tmo sphe r ic c a l ib ra t ion c urve c an m ake i td i ff i cu l t t o d a te N ew Z ea land p r eh is to ry u s ing c ha r coa l , e spec ia l ly a f t e r c a . 1 500 c a l AD . T h is c ause s a n a r t if ic ia l s p read ing o fc a l ib ra ted d a ta , a nd t h us mu l t ip le a ge r a nge s . S he l l a g e s c a l ib ra ted u s ing t h e r e se rvo ir c o r rec t ion m e thod a l so i n co rpo ra te t h i s p henomena , a s i lu s t ra ted i n t h e s i t e s a na ly sed a bove . T he m ode l led m a r ine c u rve c a l ib ra t ion m e thod h a s b e en s hown t oa vo id m u l t ip le a ge r a nges b ecau se o f t h e s moo thne s s o f t h e S t u ive ra nd B raz iuna s ( 1993) c urve . T he a na ly s i s o fs he l l a ge s c a l ib ra ted u s ing b o th ma r ine s h e l l c a l ib ra t ion m e thod s a bove , i n d ica te s t ha t t h e c a l ib ra t ion m e thod s o n ly b eg in t o d i f f e r s i gn if i can t ly a f t e r 1 500 c a l AD . T h is a f f e c t s m a r ine s h e l l CRAs l e s st h an 8 00 ±4 0y ea r s B P .

1 - 1 : 1- 1Ma r ine S he l l CRA v s . C ha rcoa l CRA —

1 000 —

a nd D if f e rence s

F ixed R e se rvo ir C o r rec t ion ( R= 3 85 y ea r s )

— — Mode l led Ma r ine C u rve *

On ly 1C ha rcoa l CRA a va i lab le

7

9 00 -

8 00 -

7 00 -

6 00 -

5 00 1 00

2 00

3 00

4 00

5 00

6 00

7 00

C harcoa l CRA F igu re 7 . 2 1 . G raph s how ing p oo led mean ma r ine s he l l CRA v s . p oo led m ean c ha rcoa l CRA c a lcu la ted f r om t h e a r chaeo log ica l s i te s i nT ab le 7 . 22 , p lo t ted a ga in s t t h e f i xed r e servo i r c o r rec t ion l i ne f o r N ew Z ea land , a nd t h e S tu ive ra nd B raz iuna s( 1 993 ) mode l led ma r ine c u rve f o rt h ep e r iod 2 00 t oy ea r s7 00 B P .

8 8

A na ly s is o fR ad io ca rbon A ge s

CHAPTER 7

1 0 00 Ma r ine S he l l CRA v s . C ha rcoa l CRA

( R^2 = 0 . 649 )

Mar ine S he l l CRA

9 00 -

8 00 -

7 00 -

6 00 2 00

3 00

4 00

5 00

6 00

7 00

Charcoa lC l F tA

1 000 1-1 2 — I Ma r ine S he l l CRA v s . C ha rcoa l CRA (R^ 2 = 0 . 642 )

Mar ine S he l l CRA

9 00 -

8 00 -

7 00 -

6 00 2 00

3 00

4 00

5 00

6 00

7 00

Charcoa l CRA F igu re 7 .22 . P o lynom ia l ( o rde r 3 ) c urve ( t op ) a nd s t ra igh t l i ne l i nea r r eg re ss ion ( bo t tom) f i t ted t o R ( t ) v a lue s c a lcu la ted f o rt h ea r chaeo log ica l s i tes d a ted i nt h is s t udy .

8 9

CHAPTER 7

Ana lys is o fR ad ioca rbon Age s

When c onven t iona l ma r ine s he l l r ad ioca rbon d a te s o lde rt han 8 00 ± 4 0 y ea r s BP a r e c a l ib ra ted u s ing e i ther s he l l c a l ib ra t ion m e thod , t h e a ge r anges a r e i n c l o se a g reemen t . T he c a l ib ra ted ma r ine s he l l r ad ioca rbon d a tes f r om K okohu ia L aye r 5( F igure 7 . 4 ) ; P onu i I s land s i tes N43 / 1 , L aye r D( F igu re 7 . 7 ) , N 43 /333 , L aye r D( F igu re 7 . 8 ) , a nd 1 4 ( F igure 7 . 9 ) ; s i te N 25 /95 , L iga r B ay ( F igures 7 . 11 a nd 7 . 12 ) ; a nd S awp i t P o in t( N26 /214 )( F igure 7 . 14 ) i lus t ra te t h is . C onven t iona l m a r ine s he l l r ad ioca rbon a ges y ounge r t han 8 00 ± 4 0 B P , h oweve r , f a l l i n to t h e c a l ib ra ted p e r iod o fc a . 1 500 c a l AD o nwa rds , w he re t wo s i gn if ican t ' w igg les ' i nt h e a tmosphe r ic c a l ib ra t ion c urve o ccur ( F igu re 7 . 23) . T h is r e su l t s i n as p read i n s ome r e se rvo i r c or rec ted c a l ib ra ted s he l l a ge r a nges . T h is i sp a r t icu la r ly n o t iceab le a t A rea B ( S8 / 171) , A o tea ( F igure 7 . 6 ) ; K okohu ia L aye r s 2 t o 4 ( F igu res 7 . 1 -7 . 3) ; S i te 2 7 , P onu i I s land ( F igu re 7 . 10 ) ; a nd s i te N 25 /26 , L iga rB ay ( F igu re 7 . 13) . T he e f f ec t o f t h e se ' w igg le s ' when c a l ib ra t ing s he l l a ges y ounge r t h an 8 00 ± 4 0 y ea r s B P u s ing t h e r e se rvo i r c or rec t ion m e thod , c an make t h e i n te rp re ta t ion o f a r chaeo log ica l e ven ts i n t h e p os t -1500 AD p e r iod o f N ew

9 00

5 50

4 50

[I I

II

3 50

Z ea land p r eh is to ry d i ff icu l t ( s ee McFadgen e ta l . 1 994 ) . T h is c an b e i l us t ra ted b y s imu la t ing c a l ibra ted d a ta f o r s he l l d e term ina t ions u s ing b o th c a l ib ra t ion m e thods ( F igu res 7 . 24 a nd 7 . 25 ) . T he s imu la t ion b eg ins w i th ac onven t iona l ma r ine s h e l l r ad ioca rbon a ge o f8 00 ± 4 0 y ea r s B P ( r ead ing f r om t h e b o t tom o ft h e p age , F igu re 7 . 25) . T h i s a ge i sf i r s t c a l ib ra ted o n t h e a tmosphe r ic c u rve a f te r s ub t rac t ion o f t h e N ew Z ea land r e se rvo ir c or rec t ion o f3 85 y ea r s ( g iv ing ar e se rvo i r c or rec ted a ge o f4 15 ± 4 0 BP ) . S econd , t h e 8 00 ± 4 0 y ea r s B P s he l l a ge i s c a l ib ra ted u s ing t h e mode l led ma r ine c a l ib ra t ion c urve ( F igu re 7 . 25) . T he s imu la t ion e nd s w i th t h e c a l ib ra t ion o f ac onven t iona l ma r ine s he l l r ad ioca rbon a ge o f 6 10 ±4 0y ea r s B P( F igu re 7 . 24 ) . F o r t h e m a r ine s he l l c onven t iona l r a d ioca rbon a ge o f8 00 ± 4 0 y ea r s B P , t h e r e se rvo i rc or rec ted c a l ibra ted av i ss l igh t ly o l de rt h an t h e mode l led m a r ine c urve c a l ib ra ted 4C d a te , b u t b o th h ave ' t igh t ' a ge r a nges ( F igu re 7 . 25) . F rom 7 90 ± 4 0 y ea r s B P t o 7 60 ± 4 0 y ea r s BP , h oweve r , t h e a ge r ange s p roduced b y t h e r e se rvo i r c or rec t ion c a l ib ra t ion m e thod b eg in t o w iden b ecause o f a' w igg le ' i n t he a tmosphe r ic c a l ib ra t ion c urve ( F igu re 7 . 25) . A t7 50 ±4 0 y ea r s B P ,

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A na lys is o fR ad ioca rbon Age s

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c a l R D F i gu re 7 . 24 . S imu la ted r ad ioca rbon a ge c a l ib ra t ion s u s ing b o th m a r ine s he l l c a l ib ra t ion m e thod s b eg inn ing w i th am a r ine s he l l c onven t iona lr a d ioca rbon a ge o f7 00 ±4 0 y ea r s B P . ( M M =s he l l CRA c a l ib ra ted u s ing mode l led m a r ine c u rve ; RC = s he l l CRA c a l ib ra ted u s ing r e servo ir c o r r ec t ion m e thod . ) .

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c a l R D F i gu re 7 . 25 . S imu la ted r a d ioca rbon a ge c a l ib ra t ion s u s ing b o th m a r ine s he l l c a l ib ra t ion m e thod s b eg inn ing w i th am a r ine s he l l c onven t iona l r a d ioca rbon a ge o f8 00 ± 4 0 y ea r s B P . ( MM = s he l l CRA c a l ib ra ted u s ing mode l led m a r ine c ur ve ; R C =s he l l CRA c a l ib ra ted u s ing r e se rvo ir c or r ec t ion m e thod . ) .

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F igu re 7 . 26 . S tu ive r a nd B raz iuna s ( 1993 ) m ode l led m a r ine c a l ib ra t ion c ur ve f o r t h e p e r iod 1 400 t o 1 950 c a l AD .

I s land ( F igu r e 7 . 15 ) a r e e xamp les w he r e t h e a r cha eo log ica l e v idence a nd e xcava to r 's i n terp re ta t ion o f t h e t i me o f o ccupa t ion o f t h e s i te s a r e mo re i n l i ne w i th t h e m ode l led m a r ine c urve c a l ib ra t ion s , t h an t ho se u nde r taken u s ing t h e r e se rvo i rc or rec t ion m e thod . T he s he l l CRAs o fl e s st h an 6 50 ±4 0 y ea r s B P f r om t h e se s i t es c a l ib ra ted u s ing t h e r e se rvo i r c or rec t ion m e thod , i mp ly t h a t t h ese s i t e s c ou ld h ave b een o ccup ied u p u n t i l t h e p r e sen t d ay . T he a r chaeo log i s t s w ho e xcava ted t h e se s i te s , h oweve r , b e l ieved t h a t t h ey w e re o ccup ied b ef o re E u ropean a r r iva l , b u t a f te r 1 600 AD . T he mode l led m a r ine c urve c a l ib ra t ion s , t h e ref o r e , a ppea r t o p rov ide a mo re a ccu ra te i n d ica t ion o f w hen o c cupa t ion a c tua l ly o ccur r ed .

m a r ine s he l l CRAs c a l ib ra ted u s ing t h e mode l led m a r ine c u rve a l so b eg in t oe xpe r ience aw iden ing o ft h e i r c a l ib ra ted a ge r a nges i nr e sponse t o af l a t ten ing o ft h is c ur ve f r om a n i n c rea se i n ' 4C l e ve ls f o r t h e m ixed l a ye r o cean ( F igu re 7 . 26 ) . B e tween 7 40 ± 4 0 y ea r s B P a nd 6 70 ± 4 0 y ea r s B P , b o th c a l ib ra t ion m e thods a ga in p roduce s im i la r a ge r a nge s , a nd a t 6 50 ± 4 0 y ea r s B P t h ey a r e i n c l o se a g r eemen t ( F igu re s 7 . 24 a nd 7 . 25) . A f te r 6 50 ± 4 0 y ea r s B P , h oweve r , t h e a tmo sphe r ic c a l ib ra t ion c ur ve o nce mo re e xpe r ience s ' w igg le s ' , c aus ing a ge r a nge s p roduced b y t h e r e se rvo i r c o r rec t ion t e chn ique t oe x tend t h rough t ot h e mode rn p e r iod . T he r e se rvo i r c or rec t ion a nd mode l led m a r ine c u rve c a l ib ra t ion m e thod s , t h e r ef o re , o n ly d i sag ree f o r t h e c a l ib ra t ion o fm a r ine s he l l d a te sb e tween 7 90 ± 4 0 a nd 7 60 ± 4 0 y ea r s B P , a nd y ounge rt h an 6 50 ± 4 0 y ea r s B P . F o rt h ese s he l l CRAs , t h e mode l led m a r ine c u rve p rov ide s t i gh te r c h rono log ica l c on t ro l , m ean ing t h a t a r chaeo log ica l e ven t s y ounge r t h an 1 500 AD a nd b eyond t h e t ime o f C ook 's a r r iva l i n1 769 , m ay b e mo re p r ec i se ly d a ted .

F ur the r t e s t ing o ft h e c a l ib ra t ion o fm a r ine s h e l l d a t e s f r om a r chaeo log ica l s i t e s b e l ieved t oh ave b een o ccup ied b e tween 1 500 AD a nd E u ropean a r r iva l wou ld f u r the rc onf irm u se o f t h e mode l led m a r ine c u rve f o r t h is p e r iod o f N ew Z ea land p r eh is to ry . D o t h e c a l ib ra ted a ge r a nge s o b ta ined u s ing t h e m ode l led m a r ine c urve c a l ib ra t ion m e thod a ccu ra te ly r e f lec t t h e t ime a tw h ich a n a r chaeo log ica l e ven t t ook p l a ce? T he a na ly s is p r esen ted a bove s ugges t st h a tt h e a ge r a nge s p roduced b yt h e mode l led m a r ine c u rve a r e at r ue r ep r e sen ta t ion o fw hen t h e a r chaeo log ica l e ven t s o ccur r ed i n N ew Z ea land p r eh is to ry .

T he ' t igh t ' mode l led ma r ine c a l ib ra t ions f o r t h i s p e r iod d o a ppea r t ob e a ccu ra te i nr ef lec t ing t h e a ge o fa r chaeo log ica l e ven t s , w hen a r chaeo log ica l e v idence i su sed a s ar e la t ive a ge c heck o nt h es i te c h rono logy . T he c a l ib ra t ion sf r om A rea B , A o tea ( F igu r e 7 . 6 ) , a nd s i te N 43 /333 , L aye r B , P onu i

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A na lys is o fR ad ioca rbon Age s

CHAPTER 7

T h is c an b e s e en i nt h e c l o se a g reemen t b e tween mode l led m a r ine c urve c a l ib ra ted d a te s , a nd c a l ib ra ted c ha rcoa l a ges f r om i d en t ica l s t ra t ig raph ic h o r izon s . I n a dd i t ion , t h e m ode l led m a r ine c urve a ppea r s t o s u cce s sf u l ly s imu la te c hange s i n R ( t ) t h rough t ime ( F igu re 7 . 2 1) . T he AR v a lue c a lcu la ted f r om t h e s i tes a na ly sed i nt h i ss t udy i ss t a t is t ica l ly i n d is t ingu i shab le f r om t h e c ur ren t N ew Z ea land AR v a lue ( Tab le 7 . 22 ) , s uppo r t ing t h e c onc lus ion o fH igham a nd H ogg ( 1995 ) a nd McFadgen a nd Mann ing ( 1990 )o f as i ngu la r l a ck o f a ny t empo ra l v a r ia t ion i n t h i s v a lue o ve r t h e l a s t m i l lenn ium i nN ew Z ea land w a te r s . A l so , t h e s imu la t ions s how t h e c l o sene s s o fb o th m a r ine s he l l c a l ib ra t ion m e thod s , a nd t h a t n o t iceab le d i f f e r ence s o n ly o ccu r w i th c e r ta in m a r ine s he l l CRA i n t h e p o s t -1500 c a l AD p e r iod , t h ough t h e se d i f f e rence s c an b e r educed b y i n co rpo ra t ing a r chaeo log ica le v idence .

9 3

CHAPTER 7

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9 4

CHAPTER 8 D ISCUSS ION AND CONCLUSIONS

OVERV IE W T he r e l iab i l i ty o f ap a r t icu la r s amp le t ype f o r r a d ioca rbon d a t ing i sa n i mpo r tan tv a r iab le f o rt h e p r eh i s to r ian s e ek ing t o b u i ld a ccura te c h rono log ie s . Au sef u l s amp le t ype s hou ld b y d ef in i t ion b e i n dependen t ly a ccu ra te a nd p rov ide a dequa te r e p roduc ib i l i ty a mong s t ag roup o fr e pea t m ea su remen t s o n t h e s ame m a te r ia l . C a ref u l s t ud ie s h ave s hown t h a t i ft h e se v a r iab le s a r e n o t c r i t ica l ly e va lua ted p r io r t o r a d ioca rbon d a t ing a na ly s i s , s i gn if ican te r ro r sm ay e ven tua te . I n C hap te r 3 , d i ve r se o p in ion s f r om a r chaeo log i s t s w e re p r e sen ted c once rn ing t h e r e l iab i l i ty o fd i f f e ren t s amp le t y pes f o r r a d ioca rbon d a t ing N ew Z ea land a r chaeo log ica l s i t e s . I t w a s f ound t h a t o f t h e m any o p in ion s e xp re s sed , o n ly a h andf u l w e re b a sed u pon c a ref u l s c ien t if ic a na ly se s . P r io rt o 1 976 , t h e s i ng le mo s t c r i t ica l e r ro r c once rned w i th d a t ing w a s i n bu i l t a ge o f c ha r coa l , b u t i tw a s r a r e ly c on s ide r ed w hen c ompa r i son s w i th m a r ine s he l l o r b one c h rono log ie s w e re m ade . A dd i t iona l ly , c ompa r ison s b e tween r a d ioca rbon d a te s o f d i f f e r en t s amp le t ype s f r om a r chaeo log ica l s i t e s , w e re o f t en u nde r taken w i thou t d ue c on s ide ra t ion o f t h e p r ec i se s t ra t ig raph ic l o ca t ion o f t h e s amp le s i n vo lved , a nd w i thou t r i go rou s a s se ssmen t o ft h e r e l iab i l i ty o ft h e s amp le i nd a t ing as p ec if ic p reh is to r ic e ven t . I ns ome c a se s ,t h e p o s t d epo s i t iona l h i s to ry o ft h e s i te s w a s o ve r looked . Af t e r 1 976 , t h e i d en t if i ca t ion o fc ha r coa l s amp le s t ot w ig s o fs ho r t l ived s p ec ie s p r io r t o d a t ing i mp roved r e l iab i l i ty m a rked ly . H oweve r , c ompa ra t ive s t ud ie s a f t e r t h is t ime w e re a f f ec ted b y af a i lu re o fr e sea rche r s t od i f f e ren t ia te b e tween s amp le s c omp r i s ing i d en t if ied c ha rcoa l , a nd t h o se w h ich d i dn o t . C ha rcoa l w a s t h e o n ly m a te r ia l c on s ide red r e l iab le b y m any N ew Z ea land a r chaeo log i s t s a f t e r 1 976 . T he u sef u lne s s o f d a t ing m a r ine s he l l , w h ich b ecame ac ommon ly u sed s amp le t y pe b y a r chaeo log is t s a f te r t h is t ime , w a s s t i l l r e la t ive ly u nknown . B ecau se o f t h is , A nde r son ( 199 1) , i nh i s c r i t ica l a na ly s i s o f t h e N ew Z ea land r a d ioca rbon r e co rd , f o cu s sed p r inc ipa l ly u pon t h er ad ioca rbon d a te so fc ha r coa l . I tw a sn o t u n t i l 1 993 , t h a t t h e a pp l icab i l i ty o f m a r ine s h e l l f o r r a d ioca rbon d a t ing N ew Z ea land p r eh i s to ry w a s c l o se ly e xam ined ( s ee H igham 1 993) , b y c ompa r ing p a i red r a d ioca rbon d a te s f r om i d en t i f ied c ha rcoa l , w i th m a r ine s h e l l . Two o f t h e t h ree s i te s s t ud ied b y H igham ( 1 993 ) , s howed a g reemen t b e tween t h e t wo s amp le s t ype s , b u t a t P l ea san t R ive r , a noma l ie s b e tween m a r ine s he l l r a d ioca rbon d a te s o n v a r iou s s he l lf i sh s pec ie s , a nd t h e i r p a i red c ha r coa l r a d ioca rbon a ge s w e re f ound . H igham ( 1993) i n i t ia l ly s ugge s ted t h a t t h e d i f f e rence s i n r a d ioca rbon a ge b e tween s h e l lf i sh s p ec ie s may h ave b een d ue t o e s tua r ine s h e l lf i sh i n corpo ra t ing y oung c a rbon f r om t e r re s t r ia l r un -of f . F ur the r r a d ioca rbon d a t ing r evea led t h a t t h e mo s t l i ke ly e xp lana t ion w a s t h a t t h e s i te h ad s uf f e red p o s t -depo s i t iona l d i s tu rbance ( H igham p e r s . c omm . ) .

I tw a s f ound i nC hap te r 3t h a t o ve r t h e l a s t 2 0 y ea r s , many mo re s he l l s amp le s h ave b een d a ted t h an c ha r coa l f r om N ew Z ea land a r cha eo log ica l s i t e s ( i n t h e Wa ika to l a bo ra to ry s i nce 1 980 , f o r i n s tance , t h e r a t io i s3 : 1 i nf a vou ro fs he l l ( H igham p e r s . c omm . ) . F ur the r e xam ina t ion o f s h e l l f o r d a t ing w a s t h e ref o re s e en t ob e i mpo r tan t . As o lu t ion t ot h e s amp le t ype d i lemma w a s i n t u rn p roposed . T h i s i n vo lved a f u r the r c ompa r ison b e tween p a i red c ha r coa l a nd m a r ine s he l l r a d ioca rbon d a te s f r om t h e s ame a r cha eo log ica l p rovenance . I nc on t ra s t t o mo s t p rev ious s t ud ie s , t h ough , a l t h e c ha rcoa l w ou ld b e c a r ef u l ly i d en t if ied p r io r t or a d ioca rbon d a t ing a s H igham ( 1993 ) h ad d one , a nd a g r ea te r v a r ie ty o f s he l lf i sh s pec ie s t e s ted . C ha rcoa l a nd m a r ine s he l l p a i r s f r om a r chaeo log ica l s i te s f r om v a ry ing l o ca t ion s a nd e nv i ronmen t s a r ound N ew Z ea land w ou ld b e s e lec ted f o r a na ly s i s . I n a dd i t ion , t h e t wo m e thod s a va i lab le t o a r chaeo log is t s t oday f o r c a l ib ra t ing c onven t iona l ma r ine s he l l r ad ioca rbon d a te s w ou ld b e s c r u t in i sed t oa s ce r ta in t h e r e l iab i l i ty o fe a ch f o rN ew Z ea land p r eh i s to ry . I nC hap te r4 ,f a c to r s w h ich c an a f f ec tt h e r a d ioca rbon d a t ing o f c ha rcoa l a nd ma r ine s he l l s amp le s w e re e xam ined . T he r a te o f d ecay o f w ood a f t e r d ea th w a s f ound t o b e a n a dd i t iona l v a r iab le i n d e term in ing i n bu i l t a ge , e ven i n s uppo sed ly r e l iab le s hor t l ived s p ec ie s . I n c e r ta in e nv i ronmen t s a nd u nde r t h e r i gh t d epo s i t iona l c ond i t ion s , t w ig s may s u rv ive f o r m any y ea r s a nd t h u s i n co rpo ra te s e r iou s e r ro r s i n r ad ioca rbon d a te s . P a r t icu la r t r ee s pec ie s c on s ide red t ob e l o ng l ived a nd n o t s u i tab le f o r d a t ing c an d ecay r ap id ly a f te r d ea th , a nd m ay n o t n ece s sa r i ly b e u nsu i tab le f o r d a t ing . T he l i f e e xpec tancy o fv a r iou s n a t ive t r ee a nd s h r ub s pec ie s w a s a l so f o und t o b e c on t rove r s ia l . C er ta in s ho r t l ived s pec ie s c an p o s s ib ly l i ve f o r af a rg rea te r p e r iod o ft ime t h an h a sb een s ugge s ted . U pwe l l ing , t h e h a rd w a te r e f f ec t , a nd t h e i n co rpo ra t ion o f o rgan ic ( me tabo l ic ) c a rbon , a r e f a c to r s w h ich m ay a f f ec t r a d ioca rbon d a te s o fs he l l . E xamp le s f r om d i f f e r en t c on tex t s i l u s t ra t ing t h e e f f ec t s o ft h e se e r ro r s w e r e s hown . O n ly o ne e xamp le o f am a r ine h a rd w a te r e f f ec t w a s f o und , i n vo lv ing s he l lf i sh l i v ing u pon l i me s tone s t ra ta , a nd w a s i d en t if ied a s p o s s ib ly b e ing s pec ie s s pec if ic ( Dye 1 994 ) . T he mo s t c ommon e nv i ronmen t f o r h a rd w a te r w a s c oa s t l ine s a s soc ia ted w i th l a rge f r e sh w a te r i n pu t s , a nd e nc lo sed f r e sh w a te r l a ke s . O n ly t wo o rgan ic c a rbon e f f ec t s w e r e n o ted . I n t h e c a se o fL i t t le ( 1993 ) , t h e c onc lu s ion t h a t o rgan ic c a rbon h ad a f f ec ted t h e a ge o f r a d ioca rbon d a te s w a s c on s ide red u n l ike ly b ecau se t h e c ha rcoa l s amp le su s ed i nh e rs t udy w e re n o t i d en t if ied . I nbu i l t a ge m ay b e c on s ide r ed amo re l i ke ly e xp lana t ion f o r L i t t le 's ( 1993 ) o b se rved v a r ia t ions i n r a d ioca rbon m ea su remen t s . H igham 's ( 1 993 ) s ugge s t ion t h a t v a r ia t ion i n r a d ioca rbon a ge r e la ted t o mode rn o rgan ic c a rbon i n co rpo ra t ion i n to s he l lf ish a tP l ea san t R ive rh a s b een a dd re s sed a bove .

9 5

D iscuss ion a nd C onc lus ions

CHAPTER 8

T he 1 e xcava ted a r chaeo log ica l s i t e s s amp led b y t h e a u tho r t oo b ta in p a i r ed c ha r coa l a nd ma r ine s he l l r ad ioca rbon d a te s f o r t h is s t udy w e re d e sc r ibed i nC hap te r 6 .T he se s i te s w e r e e xcava ted i n r e g ions c on ta in ing v a ry ing a moun t s o f a s soc ia ted c a lca r eous g eo log ica l s t ra ta , t o c ons ide r t h e h a rd w a te r e f f ec t . A v a r ie ty o f s he l lf i sh s p ec ies f r om e s tua r ine , s a ndy a nd r o cky s ho r e l o ca t ions w e r e s amp led t oe xam ine t h e i n f luence o fe nv i ronmen ta l v a r iab le s o n t h e r a d ioca rbon d a t ing o fm a r ine s he l l .

A n a na ly s is o f t h e t wo c ur ren t ly a va i lab le m a r ine s he l l c a l ib ra t ion m e thod s w a s u nder taken i n C hap te r 5 . T he o r ig ina l m e thod o f c a l ib ra t ing m a r ine s he l l , u s ing a f i xed r e se rvo i r c o r r ec t ion ( R ) o rm a r ine s he l l s t anda rd ( MSS ) , h a s c au sed p rob lems i n N ew Z ea land a r chaeo logy . I n N ew Z ea land , f o r e xamp le , s i x d i f f e ren t r e servo i r v a lue s w e r e s ugge s ted b yv a r ious r e sea rche r sb e tween 1 972 a nd 1 984 , f o r c o r rec t ing m a r ine s he l l r a d ioca rbon a ge s p r io r t oc a l ib ra t ion . T h is c au sed a v a r ie ty o f i n te rp re t ive p rob lems f o r N ew Z ea land a r chaeo log is t s i n e s tab l ish ing w hen a p r eh is to r ic e ven t o ccu r r ed . B ecau se t h e r e commended r e se rvo i r c o r rec t ion v a r ied f r om b e tween 3 30 a nd 4 30 y ea r s , t h e a ge o f c on tempo ra ry a r chaeo log ica l d epo s i t s d a ted u s ing ma r ine s he l l s ome t ime s d i f f e red i n a ge b y u p t o 1 00 y ea r s . D i sc r epanc ie s b e tween c a l ib ra ted r a d ioca rbon d a tes o n c ha rcoa l a nd m a r ine s he l l f r om t h e s ame l o ca t ion w e re a l so n o ted w hen u s ing t h is m e thod o f c o r rec t ion . A no the r p rob lem i d en t if ied w i th t h e u se o f a f i xed r e se rvo i r c o r rec t ion , w a s t h a t i td i d n o t t a ke i n to a ccoun t c hange s i n R ( t )t h rough t i me .

T he a na ly s i s o f c ha r coa l /ma r ine s h e l l p a i red r a d ioca rbon d a te s i nC hap te r 7 ,r e su l ted i n 1 4 o ft h e 1 9 a r chaeo log ica l d epo s i t s y i e ld ing c a l ib ra ted ma r ine s h e l l r ad ioca rbon a ge s w h ich a g r eed w i th t h e ir p a i r ed c a l ib ra ted c ha rcoa l r ad ioca rbon d a te s w hen e i the r m a r ine s he l l c a l ib ra t ion m e thod w a su sed .

A n ew m a r ine s he l l c a l ib ra t ion m e thod k nown a s t h e Mode l led Ma r ine C urve w a s e xam ined . T he b a s is o f t h i s m e thod i s aG loba l C a rbon Mode l ( GC M ) d eve loped b y S tu ive re ta l ( 1 986 ) , w h ich w a s b a sed u pon O e schge re ta l . ' s ( 1975 ) b ox d i f f us ion mode l ( BDM ) t h a t s imu la ted t h e movemen t o f c a rbon t h rough t h e b i o sphe r e a nd wo r ld 's o cean s . T he GCM mode l s imu la te s c hange s i nm ixed l a ye r ' 4C l e ve l s t h rough t ime , p rov id ing a s moo th ma r ine c a l ib r a t ion c urve d ue t ot h e s l ow d i f f us ion o f ' 4C f r om t h e a tmo sphe re a nd d eep o cean , i n to t h em ixed l a ye ro cean . T h i s g radua l f l uc tua t ion i nm ixed l a ye r o cean ' 4C c on t ra s t s w i th h igh v a r iab i l i ty i na tmo sphe r ic ' 4C , w h ich c au se s ' w igg le s ' i nt h e a tmo sphe r ic c a l ib ra t ion c urve . T he mode l led ma r ine c u rve e nab le s t h e c a l ib ra t ion o f c onven t iona l m a r ine s he l l r ad ioca rbon d a te s , w h ich a ccoun t s f o r c hange s i nR ( t ) i nt h e m ixed l a ye r o cean t h rough t ime . A s soc ia ted w i th t h is c urve i s an on t i me -dependan t r e g iona l r e se rvo ir c o r rec t ion c a l led AR , c a lcu la ted i n as im i la r w ay a s R ( t ) , w h ich a ccoun t s f o r l o ca l r e se rvo i r a c t iv i ty t h a t d ive rge s f r om t h e s imu la ted o cean r e se rvo i r . T he n ew m ode l led m a r ine c urve h a s n o t b een e x tens ive ly t e s ted w i th a r chaeo log ica l e xamp le s . A r ev iew o f c ur ren t r e sea r ch o n t h is c a l ib ra t ion m e thod s howed t h a t m e thodo logy u s ed i n i t s i n ve s t iga t ion w e re o f ten h ampe red b y al a ck o f i d en t if ica t ion o f t h e c ha rcoa l s amp le s , a nd c u r so ry a t ten t ion g iven t o t h e l i f eway s a nd h ab i ta t s o f v a r iou s s h e l lf i sh s pec ie s d a ted . T he se s ame e r ro r s i n m e thodo logy w e re t ho se a l so b e ing m ade b y r e sea rche r s c a lcu la t ing c oun t ry s pec if ic R , a nd s os im i la rp rob lems w e re b e ing e ncoun te r ed w i th t h e c a lcu la t ion o f AR . T h i s t h e ref o re m ean tt h a t i sw a sd i ff icu l tt oa ccu ra te ly a s se s st h e u sef u lne s s o ft h em ode l led m a r ine c u rve f o rN ew Z ea land p r eh is to ry .

F o r s i te s w he re t h e c a l ib ra ted c ha r coa l a nd s he l l d a te s w e r e i n c h rono log ica l a g reemen t , n o d i f f e r ences i n r a d ioca rbon d a te s b e tween d i f f e ren t s he l lf i sh s pec ies w e re f o und . A l l s he l lf ish s p ec ie s p roduced t h e s ame a ge f o r t h e a r chaeo log ica l e ven t b e ing d a ted . T hough t h e s h e l lf i sh s pec ie s c ame f r om e s t ua r ine , s a ndy a nd r o cky s ho re e nv i ronmen t s , t h is d i d n o t a f f ec t a ccu racy . T he h a rd w a te r e f f ec t w a s n o t d e tec ted i n g a s t ropod s o r b i va lve s l i v ing d i rec t ly u pon l i me s tone s t ra ta , n o r w a s i t i d en t if ied f o r e s tua r ine s p ec ie s a s soc ia ted w i th r i ve r ine i n pu t s w h ich f l owed t h rough h igh ly c a lca reous s t ra ta . B a sed o n t h e se o b se rva t ion s , i tw a s c onc luded t h a t a t l e a s t n i ne s he l lf i sh s pec ie s c ommon ly f o und i n N ew Z ea land a r chaeo log ica l s i te s , c an b e c ons ide red r e l iab le f o r r ad ioca rbon d a t ing ( Tab le 8 . 1) . F ew p rob lems w e r e o b served r e ga rd ing t h e c ha r coa l r a d ioca rbon a ge s , b u t t h e p rob lem o fi n bu i l t a ge a ppea red t o s t i l l b e p r e sen t . A t o ne a r chaeo log ica l s i te , t wo c u l tu ra l l a ye r s h ad b een d a ted w i th f ou r c ha rcoa l r a d ioca rbon d e te rm ina t ion s . A l though a s as e t , e ach g roup o f c ha r coa l a ge s w a s s t a t is t ica l ly i n d is t ingu ishab le , s epa ra te ly , t h e y ounge s t a nd o l de s t r e su l t s w e re s t a t i s t ica l ly d i s t ingu ishab le . A t a no the r a r chaeo log ica l s i te , t h e c a l ib ra ted c ha r coa l r a d ioca rbon d a te d i f f e red i n a ge f r om i t s p a i red c a l ib ra ted s he l l r e su l t b y c a . 1 50 y ea r s ( s ee b e low ) . T h ree i mpo r tan t v a r iab le s i nt h e d a t ing o fc ha rcoa l s amp le s w e re i d en t if ied i n t h e a na ly s i s o ft h e c ha r coa l d a te s . F i r s t , w he the r t h e f o r e s t t ype s u r round ing t h e s i t e s i n p reh is to ry w as d om ina ted b y l o ng l ived o r s hor t l ived f l o ra . S econd , t h e p o s s ib i l i ty t h a t v a r iou s t r ee a nd s h rub s p ec ie s t hough t t ob e s hor t l ived m ay l i ve f o r al o nge r p e r iod o f t ime . T h i rd , t ha t v a r ia t ion s i n d ecay r a te s o ft w ig s f r om s hor t l ived t r ee s a nd s h rub sa r ound t h e c oun t ry , m ay i n vo lve t h e d i f f e ren t ia l p re se rva t ion o ft h i s m a te r ia l i nt h ea r chaeo log ica l r e co rd .

E s tuar ine

S andy S hore

R ocky S hore

A u s t rovenu ss t u tchbury i

P aph ie ss ub t r iangu la tum

C om ine l la a d spe r sa

P aph ie sa u s t ra l i s

C om ine l la v i rga ta

V ene rup i sl a rg i l l ier t i

C ra s so s t rea g lome ra ta L une l la s ma ragda P erna c ana l icu lu s

T ab le 8 . 1 . S he l lf i sh s pec ie s f ound t ob er e l iab le i nt h i ss t udy f o rr a d ioca rbon d a t ing N ew Z ea land p r eh is to ry .

9 6

D iscus s ion a nd C onc lus ions

CHAPTER 8

When c a l ib ra t ing s he l l -cha rcoa l p a i r ed d a tes , t h e m ode l led m a r ine c ur ve g ene ra l ly p roduced c a l ib ra ted a ge r a ng e s w h ich w e re i nc l o se r a g reemen t w i th t h e c a l ib ra ted c ha r coa l d a te s , t h an t h e r e se rvo i rc o r rec ted c a l ib ra ted s h e l l d a te s . S he l l d a te s c a l ib ra ted u s ing t h e r e se rvo i r c o r rec t ion m e thod s ome t ime s p roduced a ge r a nges o lde r t h an t h e m ode l led m a r ine c u rve c a l ib ra ted d a te s b y a pp rox ima te ly 2 0 y ea r s . A l so , t h e r e servo i r c o r r ec ted c a l ib ra ted ma r ine s h e l l d a te s e xp e r ienced m u l t ip le a nd e xpanded a ge r a nge s , c ompa red t o t h e ' t i gh t ' c a l ib ra t ion s p roduced b y t h e mode l led m a r ine c u rve . T he d i f f e rence b e tween b o th m a r ine s he l l c a l ib ra t ion m e thod s , w a s i d en t if ied a s b e ing d ue t o t h e ' w igg le s ' i n t h e a tmo sphe r ic c a l ib ra t ion c u rve c aus ing e xpanded a ge r a nge s , w hen c a l ib ra t ing s he l l d a te s u s ing t h e r e servo i r c o r r ec t ion m e thod . T he s moo thnes s o ft h e mode l led ma r ine c a l ib ra t ion c urve , a vo id s t h e se ' w igg le s ' , a nd t h e r ef o re p roduce s mo re c ons t ra ined a ge r a nges .

t o t h e a pp l icab i l i ty o f t h e mode l led m a r ine c u rve i n t h e c a l ib ra t ion o fm a r ine s he l l r a d ioca rbon d a tes . A n i n ve s t iga t ion o f t h e a ccu racy o f t h e mode l led ma r ine c u rve i na ge c a l ib ra t ion w a s a l so u nder taken . I nC hap te r 7 ,i t w a s s hown t h a t s he l l a ge s g r ea te r t h an 8 00 ± 4 0 y ea r s B P c a l ib ra ted u s ing b o th m a r ine s he l l c a l ib ra t ion m e thods s howed c l o se a g reemen t . T he o n ly d i f f e r ence s w e re t h a t c a l ib ra ted d a te s u s ing t h e r e se rvo i r c o r rec t ion m e thod w e re s l igh t ly o l de r , a nd m a rg ina l ly w ide r i n t h e i r a ge r a nge s . C onven t iona l m a r ine s he l l r ad ioca rbon a ge s l e s s t h an 8 00 ± 4 0 y ea r s B P c a l ib ra ted u s ing t h e r e se rvo i r c o r rec t ion t e chn ique , h oweve r , y i e lded l a rge c a l ib ra ted a ge r a nge s b ecause o fa n i n c rea se i nt h e ' w igg le s ' i nt h e p o s t 1500 c a l AD p e r iod o ft h ea tmo sphe r ic c a l ib ra t ion c ur ve .

F o rt h es i te sw he re c a l ib ra ted ma r ine s h e l la nd c ha r coa ld a te s w e re i n c h rono log ica l d i sag reemen t , p o s t -depo s i t iona l d i s tu rbance , t h e m ix ing o fn a tu ra l b ea ch s he l l d epo s i t s a nd c u l tu ra l m idden , a nd i n bu i l t a ge , w e re f ound t o b e r e spon s ib le . A t o ne s i te , p l ough ing a nd t h e b u i ld ing o f a h ome s t ead m ixed c u l tu ra l ma te r ia l f r om t wo d i f f e r ing p e r iod s . I n as e cond s i te , m idden f r om ap at e r race w a s u sed t o f i l l ap i t a nd l e ve l al i v ing t e r race l a te r i n p r eh i s to ry , c au s ing am ix o fo lde r a nd c on tempo ra ry c u l tu ra l m a te r ia l . I n co rpo ra t ion o fn a tura lb ea ch o rs ub -f o s s i l ma r ine s h e l l w i th c u l tu ra l m a te r ia l , c aused l a rge a ge v a r ia t ions b e tween m a r ine s he l l a nd c ha r coa l d a te s f r om t h ree a r chaeo log ica l d epo s i t s . H oweve r , t h e a r chaeo log ica l s i te s w he re t h i s s i t ua t ion o ccur r ed w e r e a l ready i d en t if ied b y t h e e xcava to r s p r io r t o d a t ing . A t o ne s i te , b r ief ly m en t ioned a bove , t h e c a l ib ra ted c ha r coa l a ge w a s c a . 1 50 y ea r s o l de r t h an t h e p a i red c a l ib ra ted m a r ine s he l l d a te s . T h is w a s p ropo sed a s b e ing d ue t oi n bu i l ta ge b a sed o n : 1 )t h e a ge o ft h e a s soc ia ted s he l l d a te s ; 2 )t h a t al owe r l a ye rs howed c ha r coa l a nd m a r ine s he l l c h rono log ica l a g reemen t , a nd t h e se d a te s w e r e o n ly m a rg ina l ly y ounge r t han t h e d i spu ted c ha rcoa l a ge , a nd 3 ) t h a t t h e d ub ious c ha rcoa l a ge w a s t oo o l d b a sed o n s t ra t ig raph ic g rounds . I nC hap te r 7 ,t h e a ccu racy o ft h e mode l led m a r ine c u rve i n p roduc ing r e a l is t ic c a l ib ra t ions f o r m a r ine s he l l d a t e s w a s t e s ted . T oi l u s t ra te c hange s i nR ( t )t h rough t ime , s h e l l CRA s w e re p l o t ted a ga ins t t h e i r p a i red c ha r coa l CRA s f o r s i te s w he r e t h e s he l l / cha rcoa l p a i red d a te s w e re i nc h rono log ica l a g reemen t a f te r c a l ib ra t ion . A lso p l o t ted w a s t h e f i xed r e se rvo i r c o r rec t ion l i ne f o r N ew Z ea land ( R =3 85 y ea r s ) a nd t h e m ode l led ma r ine c a l ib ra t ion c u rve f o rt h ep e r iod 2 00 t o7 00 B P . I tw a sf ound t h a tb o th c a l ib ra t ion m e thod sc l o se ly a ccoun ted f o r t h e t empo ra l v a r iab i l i ty o f R ( t ) , a nd i tw a s d i ff icu l t t o d i scern f r om t h e g raph s w h ich s he l l c a l ib ra t ion m e thod w a s t h e mos t a pp l icab le . T h i s w a s b ecau se o f t h e l a rge v a r ia t ions i n R ( t ) c a lcu la ted f r om s ome s i t e s d ue t o o n ly o ne o r t wo c ha rcoa l r a d ioca rbon a ge s b e ing a va i lab le . H oweve r , t h e R ( t ) v a lue s f r om t h e s i t e s w e re f o und t o b e s t a t is t ica l ly d i s t ingu ishab le . A dd i t iona l ly , t h e p oo led m ean AR v a lue c a lcu la ted f r om t h e a r chaeo log ica l s i t e s i n t h is s t udy , w a s i n d is t ingu ishab le f r om t h e c u r ren t N ew Z ea land AR v a lue o f2 5 ±1 5 ( H igham a nd H ogg 1 995 ) . T h i s i nt u rn s uppo r t ed t h e v i ew t ha t AR w a s n on t ime d ependen t f o r t h e N ew Z ea land p r eh is to r ic s e quence , w h ich i s ac en t r a l t h eme

9 7

A c a l ib ra t ion s imu la t ion w a s d eve loped t o i n ve s t iga te w he the r t h i s p henomenon w a s d ependen t u pon r a d ioca rbon a ge . T he s imu la t ion b egan a t8 00 ±4 0 y ea r s B P a nd r e duced i nd ecada l i n terva ls t o 6 10 ± 4 0 y ea r s B P . T h i s s imu la t ion s howed t h a t s i gn if ican t d i sag reemen t s o ccu r red b e tween t h e c a l ib ra t ion m e thod s a to n ly p a r t icu la rp o in t s i nt h ep o s t 1500 c a l AD p e r iod . T he se d i sag reemen t s o ccur red f o r s h e l l CRA b e tween 7 90 ± 4 0 a nd 7 50 ± 4 0 y ea r s B P , a nd < 650 ± 4 0 y ea r s B P . F o r t h e se s he l l a ge s , t h e r e se rvo i r c o r rec t ion m e thod p roduced w ide ly s p read a ge r a nges c ompa r ed t ot h a t o f t h e e qu iva len t mode l led m a r ine c u rve c a l ib r a ted d a te s . H oweve r , f o r t wo a r chaeo log ica l s i te s a na ly sed i nt h is s t udy w i th s he l l d a te s < 650 y ea r s B P , t h e mode l led m a r ine c ur ve c a l ib ra t ions a g reed mo re c l o se ly w i th t h e a r chaeo log is t s i n te rp re ta t ion o f t h e a ge o f t h e s i te , t h an t h e r e se rvo i r c o r rec ted c a l ib ra ted d a te s . F rom t h e c ompa r ison o f m a r ine s he l l r a d ioca rbon a ge c a l ib ra t ion m e thod s i n C hap te r 7 , i tw a s c onc luded t h a t m a r ine s he l l d e te rm ina t ion s c a l ib ra ted u s ing t h e m ode l led m a r ine c urve c a l ib ra t ion m e thod p roduced a ccu ra te c a lenda r a ge r a nge s f o r N ew Z ea land a r chaeo log ica l s i t e s , a nd mo re p r ec ise a ge r a nge s . THE SA MPLE TYPE D ILE M MA REV IS ITED T he l a rge n umbe r o fr a d ioca rbon a ge d e te rm ina t ion s d e r ived f r om t h i s s t udy h a s a l lowed t h e i d en t if ica t ion o f r e l iab le s he l lf i sh s pec ie s f o r d a t ing N ew Z ea land p r eh i s to ry . I th a s a l so s uppor ted t h e u se o f t h e mode l led m a r ine c urve f o r c a l ib ra t ing m a r ine s he l l CRA f r om N ew Z ea land a r chaeo log ica l s i te s . T he w o rk o f A nde r son ( 1 99 1) a nd S p r igg s a nd A nde r son ( 1993) h i gh l igh ted t h e p rob lems a s soc ia ted w i th c ha rcoa l r a d ioca rbon c h rono log ie s f r om N ew Z ea land a nd P o lyne s ian a r chaeo log ica l s i t e s . T he i r i n ve s t iga t ion s a lowed t h e r e jec t ion o f d ub iou s c ha rcoa l r a d ioca rbon a ge s b a sed o n f a c to r s i d en t if ied a sa f f ec t ing t h e d a t ing o ft h i s s amp le t ype ( s ee C hap te r s 3a nd 4 ) . I d en t if y ing r e l iab le s he l lf i sh s pec ie s f o r r a d ioca rbon d a t ing a l lows f u r the r e xam ina t ion o fr a d ioca rbon d a te s f r om N ew Z ea land a r chaeo log ica l s i te s . B y u nde r tak ing a n a na ly s i s o f a l a r chaeo log ica l s i te s w i th p a i red c ha rcoa l a nd m a r ine s he l l r a d ioca rbon a ge s , s he l lf i sh s pec ie s i d en t if ied a s b e ing r e l iab le i nt h is s t udy a nd a pp l ica t ion o ft h e mode l led m a r ine c u rve f o r c a l ib ra t ing m a r ine s he l l CRA m ay b e f u r the r t e s ted . I na dd i t ion , t h e d a te o fc o lon isa t ion o fN ew Z ea land m ay b e d e te rm ined b a sed o n a r chaeo log ica l s i t e s w he re b o th c ha rcoa l a nd m a r ine s he l l r a d ioca rbon c h rono log ie s a r e i n a g reemen t .

D iscus s ion a nd C onc lus ions

CHAPTER 8

"Chronome tr ic Hyg iene" f or New Z ea land Archaeo log ica l Rad iocarbon Da tes

J -t h e r a d ioca rbon a ge h a s b een d e term ined f r om r e c r y s ta l l i sed s h e l l ( Ande r son 1 99 1 :768 ; H igham 1 993 :99 ) ;

T he d a taba se s o f t h e U n ive r s i ty o f Wa ika to a nd I GNS R ad ioca rbon D a t ing L abo ra to r ies w e re s ea rched f o r a ny a r chaeo log ica l s i te s p o s se s s ing p a i red c ha rcoa l a nd m a r ine s he l l d a te s f r om t h e s ame p rovenance ( Tab le 8 . 2 ) . T o s epa ra te o u t a c cep tab le c ha r coa l /ma r ine s he l l p a i r s f r om t h i s s amp le , a" d i sca rd p ro toco l" b a sed o n t h a t d eve loped b y A nde r son ( 1 99 1) , S p r igg s a nd A nde r son ( 1993) a nd S chm id t ( 1993 ; 1 996a )w a sd ev i sed .

K -t h e s h e l l h a s c ome f r om ac a tchmen t k nown t ob e r i ch i n a nc ien t c a rbona te , w h ich i s b e l ieved b y t h e l a bo ra to ry o r r e sea rche rt oh ave a f f ec ted t he t r ue a ge o ft h e s he l l ; L -t h e s h e l l h a s c ome f r om a n e nv i ronmen t t hough t t oh ave e xpe r ienced o cean ic u pwe l l ing o f d ep le ted ' 4C , a nd i s b e l ieved b y t h e l a bo ra to ry o r r e sea rche r t oh ave a f f ec ted t h e t r ue a ge o ft h es he l l . 3 .R ad ioca rbon a ge s may a l so b er e jec ted w here :

I na pp ly ing ad i sca rd p ro toco l t or a d ioca rbon c h rono log ies , a d a te i s r e jec ted f i r s t ly i f i th a s n o t b een m ea su red o r c a lcu la ted a c co rd ing t o i n te rna t iona l c onven t ion , a nd s e cond ly , w he r ei td oe sn o td a te t h e e ven tb e ing i n ve s t iga ted . T he p ro toco l , o u t l ined b e low , w a s u sed t o i d en t if y s pu r iou s c ha rcoa l /ma r ine s h e l l p a i r s f r om N ew Z ea land a r chaeo log ica l s i te s . R e jec t ion o r a ccep tance o f d a te s w a s b a sed f i r s t o n t h e i n te rp re ta t ion b y t h e l a bo ra to ry a nd r e sea rche r o ft h e r e l iab i l i ty a nd r e levance o f t h e d a te , a nd t h en o n m yo wn i n terp re ta t ion .

N - t h e d a te s a r e f a rr emoved s t a t i s t ica l ly ( by mo re t h an t h ree s i gma ) f r om o t he r d a te s w i th t h e s ame p rovenance . S uch d a te s a ppea r o bv ious ly s pu r iou s , a nd e ven t hough n o d i r ec t r e a son m ay a c coun tf o rt h is , t h ey m us tb ev i ewed a sr i sky .

D i scard P ro toco l

4 .A rchaeo log ica lR e levance

I .C ha rcoa lr ad ioca rbon a ge sm ay b ee xc lud ed w he re :

O -A l l s amp le s d a ted mus t b e i n d i rec t s t ra t ig raph ic a s soc ia t ion w i th a n a r chaeo log ica l e ven t . A ges t a ken f r om m a te r ia ls d ef in ing a n a tu ra l e ven t w h ich c anno t b e d i r ec t ly a s soc ia ted w i th t h e a r chaeo log ica l e ven ta r e i g no red ;

A -t h e c ha r coa l h a s n o t b een i d en t if ied t o t r ee s pec ies . C ha rcoa l a nd w ood s amp le s u sed f o r r a d ioca rbon d a t ing b ef o re 1 976 i nN ew Z ea land w e re v e ry o f ten n o t i d en t if ied t ot r ee a nd s h rub s p ec ie s . H ence s uch r a d ioca rbon a ges o n s ome o ft h e se s amp le sr e ta in t h er i sk o fh i gh i n bu i l ta ge .

M -U na ccep tab le m a te r ia ls h ave b een u s ed , o r w he re t h e r e l iab i l i ty o ft h e ma te r ia l a s ad a t ing m ed ium i sa tp r e sen t u nknown f o r N ew Z ea land a r chaeo logy . T he se i n c lude p ea t a nd k uma ra .

P -D a te s f r om a r chaeo log ica l s i te s w he re t h e re i se v idence o r t h e p o s s ib i l i ty o f p o s t -depo s i t iona l d i s tu rbance a r e r e jec ted . H e re t h e e xac t p rovenance a nd c h rono log ica l i n teg r i ty o ft h e s amp le i sd ub ious ;

B -c ha r coa lu s ed f o rd a t ing a f t e r 1 976 i sk nown n o t t oh ave b een i d en t if i ed ;

5 . R e jec t ion o f s amp le s f o r r ad ioca rbon a ge c ompa r i son s

C -t h e i d en t if ied c ha r coa l d a ted i ss t i l l a tr i sk o fp o s ses s ing h i gh i n bu i l t a ge . D a te s r e jec ted o n t h is c r i te r ion s hou ld b e f ew i n n umbe r , b ecau se o f t h e p o s t 1976 i d en t if ica t ions . H oweve r , o p in ion i s d i v ided o n t h e e f f ec t o f p a r t icu la r s pec ie s o n c ha r coa l 1 4C d a te s . I n t h i s d i sca rd p ro toco l , a ny c ha rcoa l w h ich h a s n o t b een d e r ived f r om t w ig s , o r w he re t h e t w ig m a te r ia l i s d om ina ted b y l o ng l ived s pec ie s , i s r e jec ted .

c ha rcoa l /ma r ine

s he l l

Q -A l l r a d ioca rbon a ge s whe re t h e m a tch ing c ha r coa l o r m a r ine s he l l p a r tne r h a s b een r e jec ted , a r e e xc luded f r om f u r the ra na ly s i s a st h ey h ave n oc ompa r a t ive a ge . 6 .A ccep tab l eN ew Z ea land R ad ioca rbon D a te s . R -R ad ioca rbon d a te s f r om N ew Z ea land a r chaeo log ica l s i t e sa r ea ccep ted w hen t h ey p a s sa l lt h et e s t sa bove .

D -t h e c ha r coa l d a ted i s b e l ieved b y t h e l a bo ra to ry o r r e sea rche rt ob ef r om f o s s i lw ood ;

Resu l ts a nd Ana lys is

E -t h e s amp le u sed f o r d a t ing h a s b een n o ted b y t h e l a bo ra to ry o rr e sea rche rt oh ave b een o rw a s a tr i sk o fb e ing c on tam ina ted .

S i te s w i th a c cep tab le c ha rcoa l /ma r ine s h e l l p a i r s i s o la t ed f r om t a b le 8 . 2 a f te r a pp l ica t ion o ft h e d i sca rd p ro toco l , c a n b e s e en i nt a b le 8 . 3 . O n ly e i gh t s i te s f r om t h e o r ig ina l 4 0 r ema in f o r f u r the r a na lys is . T he m a jo r i ty o f s i te s w e r e r e jec ted b ecau se t h e c ha rcoa l u sed t od a t e t h e a r chaeo log ica l d epo s i t s w a s u n iden t if ied . C o lumns 4 a nd 5 i n t a b le 8 . 3 p r e sen t t h e a c cep tab le p a i r s c a l ib ra ted i ny ea r s c a l AD ( s ee C hap te r 2 ) . T he c a l ib ra ted d a te s i n c o lumn s 4a nd 5 a r e g i ven a s c a l ib ra ted a ge r ange s . When a ge r a nge s f r om

2 . Mar ine s he l lr ad ioca rbon a ge s may b ee xc lud ed w here : F-t h es pec ie sw a sn o t i d en t if ied ; G -am ix tu r eo fs pec ie sh a s b een u sed w he re o ne o r mo re o f t h e s pec ie s h a s n o t b een i d en t if ied i nt h i s s t udy a s b e ing r e l iab le f o rr a d ioca rbon d a t ing ;

c a l ib ra ted d a te s o ve r lap a t l a , t h ey a r e s e en a s b e ing i n c h rono log ica l a g reemen t ( s ee C hap te r 7 ) . T he c a l ib r a t ed r a d ioca rbon d a te s f o r e ach s i te a r e s hown i nF igu re s 8 . 1 t o 8 . 7 . Ma r ine s h e l l a ge s c a l ib ra ted u s ing t h e Mode l led Ma r ine C u rve h ave ` MM ' a ppended t o e ach c a l ib ra t ion p l o t , r e se rvo i r c o r rec ted c a l ib ra ted d a tes ' RC ' , a nd c a l ib r a t ed c ha r coa l a ge s ' Ch ' .

H -d a te s o f Amph ibo la c rena ta ( mud sna i l ) o r f r e sh w a te r s he l lf i sh , a s t h e se mo l lu sc s a r e k nown t o b e u n re l iab le f o r d a t ing ( Ande r son 1 99 1 :768 ; H igham 1 993 :122 ) ; I- t h e s amp le u sed f o r d a t ing h a s b een n o ted b y t h e l a bo ra to ry o rr e sea r che rt oh ave b een o rw a s a tr i sk o fb e ing c on tam ina ted ;

9 8

CHAPTER 8

D i s cu s s ion a nd C onc lus ions

t hese s he l lf i sh s pec ies a re r eproduc ib le . T he c ha rcoa l r ad ioca rbon d a tes f rom Awa roa ( A(p ) =4 48 ± 3 8 ( T =0 . 15 ;

C a l ib ra ted c ha rcoa l a ges f o r a l l s i tes a g ree c lose ly w i th p a i red ma r ine s he l l s amp les , c a l ib ra ted b y e i ther ma r ine c a l ib ra t ion me thod ( Tab le 8 . 3 a nd F igures 8 . 1 -8 .7 ) . T he s he l l d a te s f rom Awa roa I n le t a re s t a t is t ica l ly i n d is t ingu ishab le ( A(p ) = 7 85 ± 2 8 ( T = 0 .28 ; x2 1, 0 . 05

x21, 0.0 5= 3 .84 ) ) a nd S hag Mou th ( A(p ) =5 96 ± 3 5 ( T= 0 .0 1; X2 1 , 0 .05 = 3 .84 ) ) a re a l so s t a t is t ica l ly i nd is t ingu ishab le , a nd

=

i lus t ra te t ha t i den t if ica t ion o ft he c ha rcoa l s a mp les t o t w igs

3 . 84 ) ) , a s a re t he s he l l a ges f r om S hag Mou th ( A(p ) =9 95 ±

o f s hor t l ived s pec ies h as e f f ec t ive ly r educed i nbu i l t a ge .

1 (T = 8 . 16 ; x2 1 0 ,0 .0 5 = 2 2 .36 ) ) , i nd ica t ing t ha t d a tes o n

R e jec t ion C r i ter ia (Where a pp l icab le )

L ab N o .

S amp le T ype

S amp le P rovenance a nd D e ta i l s

CRA

N26 / 18 N26 / 18 N26 / 18 N26 / 18

Wk 1827 Wk -2094 Wk -2869 Wk -2870

C ha rcoa l ( ID ) C ha rcoa l ( ID ) S he l l ( A s ) S he l l ( Pa )

L aye r L aye r L aye r L aye r

4 30 4 60 8 00 7 70

B u l le r Mou th S 6 1/24

NZ 1284

C ha rcoa l s p .?

7 10 ±4 0

A

B u l le r Mou th S 6 1/24

NZ 1285

C ha rcoa l s p .?

6 19 +4 0

A

B u l le r Mou th S 6 1/24

NZ 1346

S he l l s p .?

Moa -hun te r o ccupa t ion l a ye r Moa -hun te r o ccupa t ion l a ye r Moa -hun te r o ccupa t ion l a ye r

C ook 's C ove N90 /644

NZ -631

C ha r coa l s p .?

5 25 ±4 4

C ook 's C ove N90 /644

NZ -632

S he l l ( Ls )

L owe r o ccupa t ion l a ye r L owe r o ccupa t ion l a ye r

F a lse I s land S I84 /3

NZ 144

C ha r coa l s p .?

3 45 +5 0

A

F a ls e I s land S 184 /3

NZ 145

C ha rcoa l s p .?

2 15 ± 5 0

A

F a l se I s land S 184 /3

NZ 14 I

S he l l ( Pa )

C ha rcoa l a s soc ia ted w i th f i sh b one , s he l l a nd a r tef ac t s C ha rcoa l a s soc ia ted w i th f i sh b one , s he l l a nd a r tef a c t s S he l l a s soc ia ted w i th f i sh b one , c ha rcoa l a nd a r tef ac t s

F ox ton F ox ton F ox ton F ox ton F ox ton

N 148 / 1 N 148 / 1 N 148 / 1 N 148 / 1 N 148 / 1

NZ -682 NZ -684 NZ -685 NZ -683 NZ 1250

C ha r coa l s p .? C ha r coa l s p .? C ha r coa l s p .? S he l l ( C s ) S he l l ( A s )

7 28 ±4 2 5 17+ 6 0 9 6 +3 0 -8 5 1 053 ±5 8 8 95 ±5 4

F ox ton N 148 / 1

NZ 1251

S he l l ( Cs )

F ox ton N 148 / 1 F ox ton N 148 / 1 F ox ton N 148 / 1

NZ 1347 NZ 1349 NZ 1479

S he l l ( C s ) S he l l ( C s ) S he l l( C s )

F ox ton N 148 / 1

NZ 1480

S he l l ( As )

L aye r FS q . G IO L aye r CS q . U l1 L aye r CS q . U ll L aye r 1S q . U 13 L aye rT T S q . V 14 L aye r AS q . U 13 L aye r BS q . V 14 L aye r DS q . T 15 L aye rT i 'S q . V 14 L aye r DS q . T 15

G len G ynk S 6 1 /24

NZ 1533

C ha rcoa l s p . ?

9 32 ± 7 6

G len G ynk S 6 1/24

NZ 1532

S he l l ( L , M )

C ha r coa l f r om o ccupa t iona l d epo s i t S he l l f r om o ccupa t iona l d epo s i t

H o t Wa te rB each N 44 /69 H o t Wa te rB ea ch N 44 /69

NZ I169 NZ 1170

L aye r 4S q . M 12 L aye r 4S q . M ll

4 37 ±4 4 4 92 ±8 7

A A

H o t Wa te rB ea ch N44 /69

NZ 117 1

C ha r coa l s p .? B la ck g r ea sy s and s p .? B la ck g rea sy s and s p .?

L aye r 4S q . MI1

1 85 ±8 6

A

S i te N ame

Awa roa Awa roa Awa roa Awa roa

I n le t I n le t I n le t I n le t

9 9

2 2 2 2

±6 0 ±5 0 ±4 0 ±4 0

7 95 +2 5

A

1 008 ±6 0

7 89 ±3 9

A A A

189±7 0 159 ±4 8 1 093 ±5 2 9 84 ±5 6 9 17+ 5 A

5 68 ±5 3

CHAPTER 8

D is cus s ion a nd C onc lus ions

S i te N ame

L ab N o .

S amp le T ype

S amp le P rovenance a nd D e ta i l s

CRA

H o t Wa te rB ea ch N 44 /69 h o t Wa te rB each N 44 /69

NZ 1296 NZ 1297

S he l l ( Pa ) S he l l ( Pa )

L aye r 4S q . M I1 L aye r 4S q . M 1112

7 83 ±4 0 8 54 ± 4 0

H ouho ra N 6 /4 H ouho ra N 6 /4 H ouho ra N 6 /4

NZA -2436 NZA -2438 NZ -7920

C ha r coa l ( ID ) C ha rcoa l ( ID ) S he l l ( C s , P a )

L aye r3 L aye r3 L aye r3

6 32 ± 8 6 7 27 ± 8 6 8 12 ± 3 7

H u rumo imo i1 12 / 347 H u rumo imo iT 12 / 347

Wk -2853 Wk -2854

C ha r coa l ( ID ) S he l l ( Pa )

L aye r3 L aye r3

MODERN 6 70 ± 5 0

K a iwaka P t . P aN 73 /222 K a iwaka P t . P aN 73 /222 K a iwaka P t . P aN 73 /222

NZ -6272 NZ -5260 NZ -6273

C ha rcoa l ( ID ) S he l l ( C s , P s ) C ha rcoa l ( ID )

L aye r 1 L aye r 1 L aye r 2F ea tu re

2 68 ± 7 5 5 4 1 ±3 2 3 22 ± 7 6

K a iwaka P t . P aN 73 /222

NZ -5258

S he l l ( C s , P a , M )

L aye r 2F ea tu r e

6 11 ± 3 4

K a t ik i P t . S 146 /4 K a t ik i P t . S 146 /4

NZ -696 NZ -697

C ha rcoa l ( ID ) S he l l s p .?

H ou se S i te 2 C on tempo ra ry m idden

8 80 ± 3 9 6 11 ± 5 6

K aupokonu iN 128 /3 K aupokonu iN 128 /3 K aupokonu iN 128 /3

NZ -722 NZ -3932 NZ -3933

C ha rcoa l s p .? S he l l ( H i ) S he l l ( Pc )

L aye r2 L aye r2 L aye r2

1 455 ± 5 8 5 10 ± 5 0 5 20 ±4 0

Manawa tu N 148 /25

NZ -6267

C ha r coa l ( ID )

4 55 ± 6 0

Manawa tu N 148 /25

NZ -5279

S he l l ( P s )

Manawa tu N 148 /25

NZ -5280

S he l l ( P s )

D une m idden S q B e ta D une m idden S q . A lpha D une m idden S q . A lpha

Moawh i tu S 10 / 13

NZ -48 1

C ha r coa l s p .?

6 74 ± 9 0

Moawh i tu S 10 / 13

NZ -482

S he l l s p .?

L owe r o ccupa t ion l a ye r L owe r o ccupa t ion l a ye r

O ld P i e rP t . S 49 /46

NZ -3827

C ha rcoa l s p .?

8 40 ± 6 0

O ld P i e rP t . S 49 /46

NZ -27 19

S he l l ( P r )

O ld P i e rP t . S 49 /46

NZ -27 18

S he l l ( L )

O ccupa t iona l d epo s i t O ccupa t iona l d epo s i t O ccupa t iona l d epo s i t

O rua rang iN 49 /28 O rua rang iN 49 /28

NZ -4177 NZ -4 179

T op o fm ud T op o fm ud

2 30 ± 8 0 2 80 ± 5 0

O rua rang i N 49 /28

NZ -4178

C ha r coa l s p .? C ha rcoa l ( B racken ) S he l l s p .?

T op o fm ud

5 7 1 ±4 0

O ru rukama tua 1 12 /437 O ru rukama tua 1 12 /437

Wk -2949 Wk -2872

C ha rcoa l ( ID ) S he l l s p .?

L aye r4 L aye r4

2 10 ± 9 0 6 90 ± 5 0

P apa towa i P apa towa i P apa towa i P apa towa i

S 184 / ? S 184 /? S 184 / ? S1 8 4 /?

NZ 1332 NZ -4267 NZ -4268 NZ 1333

C ha r coa l s p .? C ha r coa l s p .? C ha r coa l s p .? S he l l ( Aa )

L aye r L aye r L aye r L aye r

4 4 4 4

9 16 ± 8 8 8 54 ± 6 7 7 59 ± 5 7 1 38 1 ±4 5

A A A

P a te rang iN 49 / 17 P a te rang iN 49 / 17

NZ -4181 NZ -4180

C ha rcoa l s p .? S he l l ( Pa )

T h in s h e l l l a ye r T h in s h e l l l a ye r

2 70 ± 8 0 5 80 ± 5 0

A

P a te r son I n le t ,N a t ive I s land ? / ? P a te r son I n le t ,N a t ive I s land ? / ?

NZ -4 193

C ha r coa l s p .?

T op l a ye r

6 20 ± 3 0

A

NZ -4 194

S he l l ( Mea )

T op l a ye r

6 00 ± 6 0

1 00

R e jec t ion C r i ter ia ( Where a pp l icab le )

P P

Q

A

Q Q

8 07 ± 3 4 8 34 ±3 4

A

9 6 1 ±8 8

A

190 ±4 0 1 2 10 ± 3 0

A

Q

D iscus s ion a nd C onc lus ions

CHAPTER 8

S i te N ame

L ab N o .

S amp le T ype

S amp le P rovenance a nd D e ta i l s

CRA

P en t land D owns S 6 1/20

NZ 1535

C ha rcoa l ( ID )

1 3 15 ±8 0

P en t land D owns S 6 1/20

NZ 1534

S he l l ( P )

C ha rcoa l f r om f l oo rd epos i to f l i me s tone s he l te r S he l l f r om f l oo r d epo s i to f l i me s tone s he l te r

P l ea san t P l ea san t P l ea san t P l ea san t P l ea san t P l ea san t P l ea san t P l ea san t P l ea san t P l ea san t

Wk -2269 Wk -2753 Wk -2789 Wk -2790 Wk -276 1 Wk -2762 Wk -2763 Wk -2764 Wk -277 1 Wk -2772

C ha rcoa l ( ID ) S he l l ( A s ) C ha rcoa l ( ID ) C ha r coa l ( ID ) S he l l ( As ) S he l l ( P s ) S he l l ( A s ) S he l l ( Pa ) S he l l ( Cs ) S he l l ( Pa )

P LR -a r ea 1 P LR -a r ea I P RD -7 P RD 14 PRD -3 L 4 P RD -5 L 4 PRD -9 L 3 P RD 10 L 3 P RD 11 P RD -4

5 20 ± 5 0 9 10 ±4 5 50 ±9 0 7 00 ±9 0 1 070 ±4 5 110 ±4 5 9 20 ±4 5 7 90 ±4 5 7 40 ±4 5 7 80 ±4 5

P onu i I s . N43 / 1 P onu i I s . N43 / 1

NZ -7764 NZ -7765

C ha rcoa l ( ID ) S he l l ( Mea )

L aye rD L aye rD

5 35 ± 5 9 57 ±2 9

P oue r ua P oue r ua P oue r ua P oue r ua P oue r ua

NZ -6980 NZ -6999 NZ -6893 NZ -7003 NZ -6885

C ha rcoa l ( ID ) C ha rcoa l ( ID ) S he l l ( C ) C ha rcoa l ( ID ) S he l l ( Hm )

OL2 Q uad 1 OL2 Q uad 1 OL3 Q uad 1 N 1 1 F #1 OL 1 F #2

2 25 ±3 6 2 70 ± 5 0 5 46 ±3 6 4 00 ±4 0 175 ±6 8

P ounawea S 184 / 1

NZ -55

C ha rcoa l s p .?

5 00 ± 5

P ounawea S 184 / 1

NZ -57

S he l l s p .?

P ounawea S 184 / 1 P ounawea S 184 / 1 P ounawea S 184 / 1

NZ -58 NZ 1865 NZ 1864

C ha rcoa l ( ID ) C ha rcoa l s p .? S he l l ( A )

I n te rmed ia te l a ye r I n termed ia te l a ye r L owe rl a ye r L owe rl a ye r L owe rl a ye r

P ounawea P ounawea P ounawea P ounawea P ounawea P ounawea

NZ 1867 NZ 1868 NZ 1869 NZ 1870 NZ 187 1 NZ 1872

S he l l S he l l S he l l S he l l S he l l S he l l

L owe r L owe r L owe r L owe r L owe r L owe r

P u rakanu i S 164 / 18 P u rakanu i S 164 / 18 P u rakanu i S 164 / 18

NZ -4637 NZ -4746 NZ -4749

C ha rcoa l ( ID ) S he l l ( C s ) S he l l ( Cs )

L aye r2 L aye r2 L aye r2

1 030 ±6 0 8 92 ±3 0 1 020 ±3 5

P u r i r iT 12 /340 P u r i r iT 12 /340

Wk -264 1 Wk -2644

C ha rcoa l ( ID ) S he l l ( Cs )

A rea D 2 A rea D 2

MODERN 6 10 ±5 0

P u r i r iT 12 /883

Wk -2640

C ha rcoa l ( ID )

MODERN

P u r i r iT 12 /883 P u r i r iT 12 /883

Wk -2643 Wk -2646

S he l l ( Pa ) S he l l ( Cs , P a )

E xcava ted L aye r M idden F E xcava ted L aye r E xcava ted L aye r

P u r i r iT 12 /885

Wk -2642

C ha rcoa l( ID )

P u r i r iT 12 /885

Wk -2645

S he l l ( Cs )

R edc l if f s S 84 /76

NZ -438

C ha rcoa l s p .?

R edc l if f s S 84 /76

NZ 1111

S he l l ( Cs )

R ive r R ive r R ive r R ive r R ive r R ive r R ive r R ive r R ive r R ive r

S 155 /2 S 155 /2 S 155 /2 S 155 /2 S I55 /2 S 155 /2 S 155 /2 S 155 /2 S 155 /2 S 155 /2

P 5 / 195 P 5 / 195 P 5 / 195 P 5 / 195 P 5 / 195

S 184 / 1 S 184 / 1 S 184 / 1 S 184 / 1 S 184 / 1 S 184 / 1

( A ) ( C ) ( C ) ( A ) ( A ) ( C )

1 0 1

l a ye r l a ye r l a ye r l a ye r l a ye r l a ye r

E xcava ted L aye r S qua re H E xcava ted L aye r Moa h un te r o ccupa t iona l r e f use Moa h un te r o ccupa t iona l r e f use

R e jec t ion C r i ter ia (Where a pp l icab le )

1 240 ± 1 32

A

9 20 ± 5 8 10 ±6 0 8 40±70 110 ±5 0

A

1 040 ±5 0 9 20 ±5 0 1 040 ±5 0 1 030 ± 5 0 9 40 ± 5 0 9 30 ± 5 0

5 90 ±5 0 5 50 ±4 5 MODERN 6 10 ±4 5 170 ±6 0

9 47 ± 3 4

A

CHAPTER 8

D iscus s ion a nd C onc lus ions

S i te N ame

L ab N o .

S amp le T ype

S amp le P rovenance a nd D e ta i l s

CRA

S awp i t P t . N 26 /2 14 S awp i t P t .N 26 /2 14

NZ -770 1 i Wk -3099

C ha rcoa l ( ID ) S he l l ( Pa )

LIC L 1C

3 50 ± 10 8 00 ± 5 0

S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag S hag

NZ -776 1 NZ -7763 NZ -7805 NZ -7806 NZA 1175 Wk -275 1 Wk -24 10 Wk -2362 Wk -2411 Wk -24 12 Wk -2632 Wk -2752 Wk -2508 Wk -2364 Wk -2856 Wk -2857

C ha r coa l ( ID ) C ha rcoa l ( ID ) S he l l ( As ) S he l l ( H i ) S he l l ( H i ) S he l l ( A s ) S he l l ( A s ) S he l l ( As ) S he l l ( As ) S he l l ( As ) S he l l ( Pa ) S he l l ( Mea ) S he l l ( As ) S he l l ( As ) S he l l ( As ) S he l l ( As )

L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4 L aye r4

6 00 ± 5 0 5 92 ±4 8 9 65 ±2 6 1 022 ± 2 9 9 74 ± 4 9 9 60 ±4 5 1 020 ± 5 0 1 0 10 ± 5 0 9 90 ± 4 5 9 80 ± 4 5 9 80 ± 4 0 1 040 ±4 5 1 060 ±4 5 1 040 ± 5 0 9 80 ± 4 0 9 50 ± 4 5

S t ewa r tI s . ? / ? S t ewa r t I s .? / ?

NZ -422 NZ -423

C ha rcoa l s p .? S he l l ( Cs )

L aye r3 L aye r3

6 90 ± 6 0 7 30 ± 5 0

A

S unde s i te N 38 /24

NZ 1899

C ha r coa l s p .?

2 ,a bove

6 20 ± 7 0

A

S unde s i te N 38 /24

NZ -6955

S he l l( Pa )

2 ,a bove

6 6 1 ±3 6

S unde s i te N 38 /24

NZ 1898

C ha rcoa l s p .?

4 ,b enea th

6 10 ± 6 0

S unde s i te N 38 /24

NZ -6956

S he l l ( To )

L aye r a sh L aye r a sh L aye r a sh L aye r a sh

4 ,b enea th

1 0 15 ± 3 2

T a i R ua S 136 / 1 T a i R ua S 136 / 1

NZ -750 NZ -749

C ha rcoa l s p .? S he l l ( H i )

B a se o fL aye r5 B a se o fL aye r5

8 31 ± 3 3 8 15 ± 3 2

A

T a i rua N 44 /2 T a i rua N 44 /2 T a i rua N 44 /2

NZ -594 NZ -595 NZ 1875

C ha r coa l s p .? C ha r coa l s p .? S he l l ( Cd , L s )

B ed 2 B ed 2 B ed 2

8 78 ± 4 9 4 43 ± 4 0 9 10 ± 6 0

A A

T umb ledown B ay S 94 /30 T umb ledown B ay S 94 / 30

NZ -7656 NZ -7654

C ha rcoa l ( ID ) S he l l ( As )

L aye r3 L aye r3

4 18 ±4 7 7 06 ± 5 0

Whe taku ra Whe taku ra Whe taku ra Whe taku ra

T 12 /34 1 T 12 /34 1 T 12 /34 1 T 12 /34 1

Wk -2950 Wk -2873 Wk -295 1 Wk -2874

C ha rcoa l ( ID ) S he l l s p .? C ha r coa l ( ID ) S he l l s p .?

L aye r L aye r L aye r L aye r

3 20 7 70 3 20 7 10

Wa ima ta i ta i S 146 /2

NZ 1249

C ha rcoa l s p .?

Wa ima ta i ta i S 146 /2

NZ -579

S he l l s p .?

Wa ima ta i ta i S 146 /2

NZ -580

S he l l ( C . s p . )

Moa h un te r d epos i t Moa h un te r d epos i t Moa h un te r d epos i t

Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th Mou th

S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5 S 155 /5

2 2 5 5

R e jec t ion C r i ter ia (Where a pp l icab le )

A

±5 0 ±5 0 ±9 0 ±5 0

7 15 ± 4 5

A

9 40 ± 3 2 8 74 ± 4 5

T ab le 8 . 2 . N ew Z ea land a r chaeo log ica l s i te s w i th p a i red c ha rcoa l /ma r ine s h e l l r a d ioca rbon d a te s f r om t h e s ame p rovenance . N o te s : I D i n d ica te s c ha r coa l h a s b een i d en t if ied t o t r ee s pec ie s ; s p .? n o s pec ies o f f l o ra o r s h e l lf ish g i ven . Ma r ine s he l l s p ec ie s a r e i d en t if ied b y : P a P aph i e s a us t ra l i s ; P s P aph ie s s ub t r iangu la tum ; A s A us t rovenu s s t u tchbury i ; C s C h ione s t u tchbu ty i ; A a Amph id e sma a us tra l i s ; L s L une l la s maragda ; H a H a l io t i s a us t ra l i s ; H i Ha l io t i s i r i s ; C d C e l lana d en t i cu la ta ; Mea My t i lu s e d u l i s a o teanu s ; Hm H y r id e l la m enz i e s i ; T o T ha i s o rb i ta ; P c P erna c ana l icu lu s ; A Amph id e sma s p . ; CC h ione s p . ; P rP ro to thaca s p . ; LL une l la s p . ; M My t i lus s p .

1 02

D iscus s ion a nd C onc lus ions

C o lumn N o . S i t eN ame

CHAPTER 8

1 L ab N o .

2 S amp le T ype

3 C 1RA

4 C a l ibra ted A ge R ange AD l a ( A tmospher ic C urve ) 1 440 -1 528 1 558 -1 631 1 4 36 -1 493 1 603 -1 6 11 1 439 -1 492

Awa roa I n le tN 26 / 18

Wk 1827

C ha rcoa l ( ID )

4 30 ± 6 0

Awa roa I n le tN 26 / 18

Wk -2094

C ha rcoa l ( ID )

4 60 ± 5 0

Awa roa I n le tN 26 / 18

Wk -2869

S he l l ( As )

8 00 14 0

Awa roa I n le tN 26 / 18

Wk -2870

S he l l ( Pa )

7 70 ±4 0

1 445 -1 522 1 583 -1 625

K a iwaka P t . P a N 73 /222

NZ -6272

C ha r coa l ( ID )

2 68 ± 7 5

K a iwaka P t . P a N 73 /222

NZ -5260

S he l l ( C s , P s )

5 4 1 ±3 2

1 64 1 1 7 33 1 9 30 1 674 1 725 1 802 1 855 1 9 18 1 954

-1 685 -1 809 -1 954 -1 699 -1 778 -1 8 14 -1 855 -1 942 -1 954

P u r i r i1 12 /340

Wk -264 1

C ha rcoa l ( ID )

1 44 ± 3 2

P u r i r iT I2 /340

Wk -2644

S he l l( C s )

6 10 ± 5 0

P u r i r iT 12 /883

Wk -2640

C ha rcoa l ( ID )

1 68 ± 3

P u r i r iT 12 /883

Wk -2643

S he l l ( Pa )

5 90 ± 5 0

1 692 1 822 1 954 1 649 1 765 1 775 1 9 39 1 682 1 807 1 909 1 9 54 1 654 1 7 33 1 9 3 1

-1 729 -1 922 -1 955 -1 678 -1 769 -1 805 -1 954 -1 735 -1 89 1 -1 935 -1 955 -1 684 -1 808 -1 954

P u r i r i1 12 /885

Wk -2642

C ha rcoa l ( ID )

1 77 ± 3

P u r i r iT 12 /885

Wk -2645

S he l l ( Cs )

6 10 ±4 5

S awp i tP t . N 26 /2 14

NZ -770 1 i

C ha rcoa l ( ID )

3 50 ± 10

S awp i tP t . N 26 /2 14

Wk -3099

S he l l ( Pa )

8 00 ± 5 0

S hag Mou th S 155 /5

NZ -776 1

C ha rcoa l ( ID )

6 00 ± 5 0

S hag Mou th S 155 /5

NZ -7763

C ha r coa l ( ID )

5 92 ±4 8

S hag Mou th S 155 /5

NZ -7805

S he l l ( As )

9 65 ± 2 6

S hag Mou th S 155 /5

Wk -275 1

S he l l ( A s )

9 60 ±4 5

S hag Mou th S 155 /5

Wk -24 10

S he l l ( A s )

1 020 ± 5 0

S hag Mou th S 155 /5 S hag Mou th S 155 /5

Wk -2362 Wk -24 11

S he l l ( A s ) S he l l ( A s )

1 0 10 ± 5 0 9 90 ± 4 5

1 03

1 679 -1 743 1 749 -1 759 1 805 -1 823 1 827 -1 885 1 9 12 -1 938 1 954 -1 954 1 6 50 — 1 677 1 776 -1 805 1 940 -1 954 1 447 -1 671 1 78 1 -1 799 1 945 -1 953 1 4 37 -1 495 1 60 1 -1 6 16 1 328 1 390 1 329 1 392 1 327 1 39 1 1 326 1 360 1 389 1 292 1 3 39 1 294 1 30 1 1 379

-1 350 -1 427 -1 347 -1 429 -1 349 -1 4 11 -1 353 -1 367 -1 4 16 -1 333 -1 402 -1 406 -1 374 -1 409

5 C a l ibra ted A ge R ange AD I a ( Mode l led Mar ine C urve )

1 462 -1 520 1 479 -1 545

1 693 -1 814

1 649 -1 703

1 660 -1 7 19

1 652 -1 700

1 457 -1 527

1 350 -1 4 16 1 338 -1 428

1 302 -1 397 1 306 -1 403 1 3 19 -1 412

CHAPTER 8

D iscuss ion a nd C onc lus ions

C o lumn N o .

1 L ab N o .

S i te N ame

2 S amp le T ype

3 CRA

S hag Mou th S 155 /5

Wk -2412

S he l l ( As )

9 80 ± 4 5

S hag Mou th S 155 /5

Wk -2632

S he l l ( Pa )

9 80 ± 4 0

S hag Mou th S 155 /5

Wk -2508

S he l l ( As )

1 060 ± 4 5

S hag Mou th S 155 /5

Wk -2364

S he l l ( As )

1 040 ± 5 0

S hag Mou th S 155 /5

Wk -2856

S he l l ( As )

9 80 ± 4 0

S hag Mou th S 155 /5

Wk -2857

S he l l ( As )

9 50 ± 4 5

T umb ledown B ay S 94 /30 T umb ledown B ay S 94 /30

NZ -7656

C ha rcoa l ( ID )

4 18 ± 4 7

NZ -7654

S he l l ( As )

7 06 ± 5 0

4 C a l ibra ted A ge

5 C a l ibra ted Age

R ange AD 1 0( A tmo spher ic C urve )

R ange AD IG (Mode l led Mar ine Curve )

1 304 1 385 1 316 1 386 1 285 1 353 1 368 1 288 1 347 1 3 16 1 386 1 328 1 390

1 324

-1 37 1 -1 4 11 -1 370 -1 4 10 -1 325 -1 358 -1 388 -1 3 30 -1 393 -1 370 -1 4 10 -1 350 -1 422

1 4 17

1 326 -1 4 15 1 284 -1 335

1 293 -1 377 1 326 -1 4 15 1 348 -1 433

1 445 -1 527 1 559-1631 1 49 1 -1 604 1 608 -1 650

1 519 -1 654

T ab le 8 . 3 . A ccep tab le p a i r s o fc ha rcoa l a nd ma r ine s he l l r a d ioca rbon d a te s f r om N ew Z ea land a r chaeo log ica l s i te s .

Wk-2870 M M

Wk-2869 M M

Wk-2870 R C

E n --1

Wk-2869 R C

Wk-2094 C h

Wk-1827 C h

[ i t ' l l 't i 1 000

100

' m i l l i 1 200

I 1 300

t i

1 400

1 500

1 600

t i l 1 700

1 800

II

1 900

c a l R D

F igur e 8 . 1 . C a l ib ra ted r a d ioca rbon a ge s f r om Awa roa ( N26 / 18 ) . ( MM = s h e l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC = s he l l c a l ib ra ted u s ing R e se rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha rcoa l a ge ) .

1 04

D iscuss ion a nd C onc lus ions

CHAPTER 8

I

N Z-5260 M M

I

H I n -I r i

I

1 ' I

Mt N Z-5260 R C

H NZ-6272 C h

111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

2 000

M

2 100

c a l R D

F igu r e 8 . 2 . C a l ib ra ted r ad ioca rbon a ge s f r om K a iwaka P o in tp a ( N73 /322 ) , L aye r 1 .( MM =s he l l c a l ib ra ted b y Mode l led Ma r ine C urve ; RC = s he l l c a l ib ra ted u s ing R e se rvo i r C o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

Wk2644 MM

1 '11

Wk2644 R C

I H

1 1°— °£ 4

1 000

l um

Ino

1 300

l em

1 500

1 600

1 700

1 000

1 9 1 :M

Wk264 1 C h

2 000

2 100

2 200

c a l R D

F igu r e 8 . 3 . C a l ib ra ted r a d ioca rbon a ge s f r om s i te 1 12 /340 , P u r i r i . ( MM =s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC =s h e l l c a l ib ra ted u s ing R e se rvo i rC o r r ec t ion m e thod ;C h =c a l ib ra ted c ha rcoa l a ge ) .

1 05

CHAPTER 8

D iscuss ion a nd C onc lus ions

Wk -2643 M M

Wk-2643 R C

1 21

I L I9

1 000

1 00

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

Wk-2640 C h

2 000

2 100

2 200

c a l A D

F i gu re 8 . 4 . C a l ib ra ted r a d ioca rbon a ge s f r om s i te T 12 /883 , P u r i r i . ( MM = s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC =s he l l c a l ib ra ted u s ing R e servo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

Wk 2 645 MM

Wk-2645 R C

1 11

1 A— (11 H

P I

Wk-2642 C h

H i m 1 000

1 00

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

2 000

2 100

2 200

c a l A D

F i gu re 8 . 5 . C a l ib ra ted r a d ioca rbon a ge s f r om s i te T 12 /885 , P u r i r i . ( MM =s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ; RC =s he l l c a l ib ra t ed u s ing R e se rvo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

1 06

D iscuss ion a nd C onc lus ions

CHAPTER 8

1 --

-n-

I ---1 2In I 1 — ° -- 1 1 1 1 ---1

H

1

I ___ 1 2_ 1 I

"1

I E

"1 " i

1 L1 --1 1 -E-

1

H 1 -1 31 I n a1 I n I F a -I I' l 1 ' 3 1 HH 1 41 H 31 1 -' 1 Ha li — cuL l E i L IH I -1 21 H l ia— I P a I

1 41 i

Wk-2857 Wk-2856 Wk-2364 Wk-2508 Wk-2752 Wk-2632 Wk-2412 Wk-2411 Wk-2362 Wk-2410 Wk-2751 N ZR-1175 N Z-7806 N Z-7805

MM mm MM MM MM MM MM MM MM MM MM

Wk-2857 Wk-2856 Wk-2364 Wk-2508 Wk-2752 Wk-2632 Wk-2412 Wk-2411 Wk-2362 Wk-24 10 Wk-2751 N ZR-1175 N Z-7806 N Z-7805

R C R C R C R C R C R C R C R C R C R C R C R C R C R C

r e l

MM MM

H 1 a I N Z-7763 C h H I i n I N Z-7761 C h i iiii ii il ii iiiiiii ll it ii iii il ii ii Ii iiili ii ii ii ii li ii in ii il ii ii ii iii li i m ini lii ii ii ii il ii ii 1 000

100

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

c a l R D

F i gu r e 8 . 6 . C a l ib ra ted r ad ioca rbon a ge s f r om S hag Mou th ( S 155 /5 ) . ( M M =s he l l c a l ib ra ted b y Mode l led Ma r ine C u rve ;R C =s he l l c a l ib ra ted u s ing R e servo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

[

I

1 -`1-1

n

N Z-7654

MM

"1 -' 1

N Z-7654

R C

N Z-7656

C h

l -I

i ii ii ii il it iii ii iih ilii iii il ii ii ti tlill mui ti li a m in l i u m wh ii ii mi lli ii i m ili i ii 1 000

1 00

1 200

1 300

1 400

1 500

1 600

1 700

1 800

1 900

c a l R D

F i gu re 8 . 7 . C a l ib ra ted r ad ioca rbon a ge s f r om T umb ledown B ay ( S94 /30 ) . ( MM =s he l l c a l ib ra ted b y Mode l led M a r ine C urve ; RC =s he l lc a l ib ra ted u s ing R e servo i rC o r rec t ion m e thod ; C h =c a l ib ra ted c ha r coa l a ge ) .

1 07

D iscuss ion a nd C onc lus ions

CHAPTER 8

P oo led Mean S he l l CRA ( A(p ) )* 7 85 ± 2 8

S i te

P oo led Mean C harcoa l CRA ( A(p ) )*

Awa roa I n le t ( N26 / 18 )

4 48 ± 3 8

K a iwaka P o in tp a ( N73 /222 ) S hag Mou th ( S 155 /5 )

2 68 ± 7 5

-5 41 ± 3 2

5 96 ± 3 5

9 95 ± 1

T umb ledown B ay ( S94 /30 )

4 18 ±4 7

7 06 ± 5 0

R ( t )

AR

3 37 ± 4 7 2 73 ± 8 2

65 ± 4 7 109 ± 8 2

3 99 ± 3 7 2 88 ±6 9

2 0 ±3 7 139 ± 6 9

3 53 ± 2 5 39 ± 3 52 7 ( T= 3 . 50 ; X23 , 0 .0 5 — 7. 8 1 ) ( T= 5 .68 ; X23 , 0 .0 5 = 7. 8 1 )

P oo led Mean ( A(p ) )*

T ab le 8 . 4 . R e se rvo i r a ge s a nd AR v a lue s c a lcu la ted f o r p r ev ious ly d a ted N ew Z ea land a r chaeo log ica l s i tes w i th a ccep tab le c ha r coa l a nd m a r ine s he l l p a i r s .* = Wa rd a nd W i l son ( 1978 ) 2 8 . S ource H igham a nd H ogg ( 1995 )

AR 2 5 ±1 5

AR v a lue f r om t a b le 7 . 22

42 ± 2 5

AR v a lue f r om t a b le 8 . 4

39 ± 3 5 3 1 ±1 52 9

P oo led Mean ( A(p ) )*

( T =0 . 40 ; x22 , 0 .0 5 =5 .99 )

T ab le 8 . 5 . A R v a lue s c a lcu la ted f r om a r chaeo log ica l s i te s a na lysed i nt h is s t udy s t a t i s t ica l ly c ompa r ed w i th t h e c ur ren tN ew Z ea land v a lue f r om H igham a nd H ogg ( 1995 ) . *= Wa rd a nd W i l son ( 1978 ) . T h i s a na ly s i s o fc ha r coa l /ma r ine s h e l l p a i r s f r om p r ev iou s ly d a ted a r chaeo log ica l s i t e s , t h e r ef o re , s uppo r t s t h e r e su l t s o f t h is s t udy i nt h e i d en t if ica t ion o fr e l iab le s he l lf i sh s pec ie s f o r r ad ioca rbon d a t ing N ew Z ea land p r eh i s to ry . T h i s i so n ly a ppa ren t t h rough a pp l ica t ion o f ad i sca rd p ro toco l b a sed o n b o th r a d ioca rbon a nd a r chaeo log ica l c ons ide ra t ions . I ts hou ld b e n o ted , t h a tt h e P u r i r i c ha rcoa l a ge s a r e n o rma l ly d esc r ibed b y r a d ioca rbon l a b s a s ' MODERN ' a s t h e i r r e se rvo i r c o r rec ted a ge i sl e s s t h an 2 00 ' 4C y ea r s B P ( s ee C hap te r2 ) . H oweve r , t oi l us t ra te t h e d i f f e rence s i nt h e t wo me thod s b y w h ich m a r ine s he l l c onven t iona l r a d ioca rbon a ge s m ay b e c a l ib ra ted , t h e a c tua l r a d ioca rbon d a te s c a lcu la ted f o rt h e P u r i r i c ha r coa ls amp le sh ave b een u sed . T he mo s t n o tab le d i f f e rence b e tween t h e mode l led m a r ine c u rve a nd r e se rvo i r c o r rec ted c a l ib ra ted m a r ine s he l l d a te s a r e t h e a ge r a nge s p r oduced b y e ach c a l ib ra t ion t e chn ique . T h is w a s a l so o b se rved i n C hap te r 7 . Whe rea s t h e a tmo sphe r ic c urve c an p roduce c a l ib ra ted a ge s w i th mu l t ip le a ge r a nge p o s s ib i l i t ie s , t h e mode l led m a r ine c urve p rov ide s c a l ib ra ted a ge s w he re t h e re i so n ly o ne s pec if ic a ge r a nge . T h is t e ndency a ppea r s t o b e t ime d ependan t w i th y ounge r ( < 1500 c a l AD ) d a te s , a s a l so c onc luded i nC hap te r 7 ,( s ee F igure s 8 . 1 t o 8 . 7 ) . T he c ha r coa l a nd m a r ine s he l l r ad ioca rbon a ge s f r om t h e a r chaeo log ica l s i te s o f Awa roa , S hag Mou th a nd T umb ledown B ay t h a t h ave b een c a l ib ra ted

o n t h e a tmo sphe r ic c u rve , s how t h a t t h e i r a ge r a nge s f a l l c l ose ly w i th in t h o se o f t h e ma r ine s he l l a ge s c a l ib r a ted o n t h e mode l led m a r ine c urve . A f te r 1 500 c a l AD , h oweve r , d a te s c a l ib ra ted o n t h e a tmo sphe r ic c u rve b ecome d i s t r ibu ted o ve r ag r ea te r t ime s pan . T hough t h e se a ge r ange s e xpand w i th r e duced r a d ioca rbon a ge , ma r ine s h e l l d a te s c a l ib ra ted u s ing t h e m ode l led m a r ine c urve r e ta in t h e i r t i gh t c h rono log ica l c on t ro l . T h i s i sp a r t icu la r ly a ppa ren t i n t h e p e r iod f r om 1 700 c a l AD o nwa rd s f o rt h e P u r i r i s i te sa nd f o r K a iwaka P o in t pa . U se o f t h e m ode l led m a r ine c urve f o r t h e p o s t 1500 AD p e r iod o f N ew Z ea land p r eh is tory i s s uppor ted b y t h e c a l ib ra t ion o f t h e m a r ine s he l l r ad ioca rbon a ges f r om t h e P u r ir i s i te s T 12 /883 a nd T 12 /885 , a nd K a iwaka P o in t pa . A t t h e P u r i r i s i t e s , t h e e xcava to r b e l ieved t h e s i te s w e re o ccup ied a f te r 1 600 AD b u t b ef o re 1 800 AD , b ecau se o fa n a b sence o f E u ropean a r tef ac t s . Whe r ea s t h e r e ser vo ir c o r rec ted c a l ib ra ted m a r ine s he l l d a te s i n d ica te o ccupa t ion o f t h e se s i te s f r om 1 640 c a l AD t o t h e p r e sen t , t h e m ode l led ma r ine c urve c a l ib ra ted a ge s a r e i n a g reemen t w i th t h e e xcava to r s ' e s t ima te s , s how ing o ccupa t ion a t c a . 1 700 c a l AD . A t K a iwaka P o in t pa , h i s to r ic r e co rds i n d ica te t h e pa w a s o ccup ied i nt h e 1 8 th c en tu ry ( 1GNS s amp le r e co rd f o rm R 9265 /3 ) . T he s h e l l a ge s c a l ib ra ted u s ing t h e m ode l led ma r ine c urve a l so s uppo r t t h i s o ccupa t ion d a te . A s im i la r

2 7

L a rge s to fw e igh t ed o ru nwe igh ted ' s ca t t e r ' m ean au s ed f o r AR r o unded u pt o 5y ea r s( s ee S t u ive re ta l . 1 986 :982 ; 1993 :155 ) .

2 8

T he P u r i r is i te se xpe r ience m u l t ip le AR v a lue sa nd s oh a ve b een om i t t ed f r om t a b le 8 . 4 . T he c ha r coa l a nd m a r ine s h e l l a ges f o rS awp i t P o in t( N26 /2 14 ) i n

T ab le 8 . 3 w e re c omb ined w i th a dd i t iona l d a te sf o rt h i ss i te i nC hap t e r 7t od e r ive i t s AR v a lue ( s ee t a b le 7 . 22 ) , t h e r ef o r en o AR v a lue f o rt h is s i te a ppea r s i n T ab le 8 . 4 . 2 9

L a rge s to fw e igh ted o ru nwe igh ted ' s ca t t e r ' m ean a u s ed f o r AR r o unded u pt o 5y ea r s( s ee S t u ive re ta / . 1 986 :982 ; 1993 :155 ) .

1 08

D iscuss ion a nd C onc lus ions

CHAPTER 8

v i nd ica t ion o f t h e mode l led m a r ine c u rve b a sed o n s i te s b e l ieved t oh ave b een o ccup ied a f te r 1 500 AD a nd p r io rt oo r j u s t a f t e rE u ropean a r r iva l , w a s o b se rved a tA rea B ( S8 / 17 1) , A o tea , a nd s i t eN 43 /33 , L aye r B ,P onu i I s land , i nC hap te r7 .

T he K okohu ia s i te m ay e nab le p r eh is to r ians t o t r ace t h e d eve lopmen t o f Mao r i c u l tu re f r om t h e l a te A rcha ic P ha se t o t h e C la s s ic P ha se i nN or th land ( Tay lo r 1 994 :17 ) . C er ta in ly , i tc ou ld i l u s t ra te t h e e nd o f moa -hun t ing , i na s soc ia t ion w i th o ccupa t ion o n t h e r i dge f o r d ef en s ive p urpo se s ( t he t i me o f o ccupa t ion o ft h e r i dge c or respond ing w i th t h e b eg inn ing o f p a b u i ld ing i n N ew Z ea land , s e e S chm id t 1 993 , 1 996a ) . A lso , t h e c hange i nf oods e xp lo i ted d u r ing t h e l a te A r cha ic ( s uch a sm oa ) , t oa n i n c rea sed d ependence o n s ea r e sou r ce s a nd r a ta nd d og i nt h eC la s s ic i sa ppa ren t .

When t h e A l l v a lue s a r e c a lcu la ted f o r t h e p r ev iou s ly d a ted s i te s , t h ey a r e i n a g reemen t w i th t h e H igham a nd H ogg ( 1995 ) v a lue , a nd t h e v a lue d e te rm ined f o rt h e s i te s s amp led a nd a na ly sed i nt h is s t udy ( s ee T ab le 7 . 22 ) ( Tab le s 8 . 4 a nd 8 . 5 ) . T h i s a na ly s is f u r the r s uppo r t s t h e c ur ren t AR v a lue f o r N ew Z ea land , a nd t h e v i ew t h a t t h e r e h a s b een n o t empo ra l

T he d a t ing o fA rea B f r om Whangapoua o n A o tea , p rov ide s o n ly a g l imp se o f p r eh is to r ic a c t iv i t ie s o n t h is i s land i n p r eh i s to ry . A rea B w a s o ccup ied i n t h e 1 7 th c en tu ry AD . T he o ccupan t s d epended u pon m a r ine r e sou rces , s u ch a s s he l lf i sh a nd f i sh , w i th a ppa ren t ly n o e xp lo i ta t ion o fb i rd s o r m amma l s . Mayo rI s land o b s id ian w a sr e ad i ly a va i lab le t ot h e s i te 's i n hab i tan t s , a ss hown b y i t sc ommon o ccu r rence i nt h e s i te , a nd a dze s w e re u sed a nd p o s s ib ly m anuf ac tu r ed . T he h ea r th s i n d ica te t h a t f ood w as b e ing p r epa red a tt h a t l o ca t ion n ex t t o t h e e s tua ry , a nd t h e d ra in -f ea tu r e s i d en t if ied i mp ly s ome s t r uc tu re m ay h ave e x is ted n ea rby , e i the r ah ou se , o ra s t o rage p i t .

v a r ia t ion i nA Ro ve rt h ep a s t 7 00 y ea r s f o rN ew Z ea land ( s ee H igham a nd H ogg 1 995 ) . The Chrono logy o f Kokohu ia , P onu i I s land , Ao tea , L igar Bay a nd S awp i tP o in t T he e a r l ie s t a r chaeo log ica l s i te s i n N ew Z ea land w i th a c cep tab le p a i red c ha rcoa l a nd m a r ine s he l l r a d ioca rbon d a te s h ave b een a na ly sed i n t h i s s t udy . B a sed o n t h e a g r eemen t s b e tween t h e c ha r coa l a nd m a r ine s he l l r a d ioca rbon c h rono log ie s , i tm ay b e p ropo sed t h a t N ew Z ea land w a sc o lon ised b y t h e 1 4 th c en tury AD , a nd p os s ib ly i n t h e 1 3 th c en tu ry AD . E ven t s w h ich t ook p l ace a t t h e a r chaeo log ica l s i te s s amp led f o r t h i s s t udy m ay n ow b e d i scus sed w i th in t h i s c h rono log ica l f r amewo rk f o r N ew Z ea land p r eh i s to ry . T ay lo r( 1 994 : 17 )h a s c ons ide red K okohu ia t ob e a n e xamp le o ft h e l a te A r cha ic p ha se o fN ew Z ea land p r eh i s to ry . T h i s s ugge s t ion i sg i ven c l ea r s uppor t b y t h e r ad ioca rbon r e su l t s o b ta ined ( o ccupa t ion b eg inn ing i n t h e m id t o l a te 1 5 th c en tu ry AD ) , t h e p re sence o f aD uf f I A a r g i l l i te a dze , a nd m oa b one ( t hough moa b one a s soc ia ted w i th e a r ly s i te s i n N o r th land m ay b e a tr i sk o fb e ing s ub -f o s s i l , s e e A nde r son 1 989 :112 ) . Af u l l a na ly s i s o f t h e c u l tu ra l m a te r ia l h a s n o t b een c omp le t ed f r om K okohu ia , b u t t h e p r e l im ina ry f i nd ing s d o s hed s ome l i gh t o n t h e p r eh i s to r ic a c t iv i t ie s f o r t h is a r ea o f No r th land . T he e a r l ie s t p r eh is to r ic i n hab i tan t s a tK okohu ia m ay h ave b een i n vo lved i n moa -hun t ing , t h ough s ho r t ly a f t e r i n i t ia l o ccupa t ion , m oa d oe s n o t a ppea r i n t h e a r chaeo log ica l r e co rd . T h i s i mp l ie s e i the r s c a r c i ty o f t h i s f a una f o r e xp lo i ta t ion , l o ca l e x t inc t ion , o r i n co rpo ra t ion o f s ub -f o s s i l m a te r ia l i n to t h e d epo s i t . T he c onse cu t ive c u l tu ra l d epos i t s i l us t ra te t h a t t h e o ccupan t s d epended h eav i ly u pon s ea r e sou rce s , b y e xp lo i t ing s he l lf i sh a nd aw ide v a r ie ty o ff i sh s p ec ies . T e r r e s t r ia l f a una a ppea r n o t t oh ave b een a s r e l ied o n e x ten s ive ly , o n ly t wo b i rd s pec ie s b e ing i d en t if ied a t p r e sen t , a nd R a t tus e xu lan s a nd C an i sf am i l ia r i s m ak ing u p t h e mamma l c omponen t o f t h e d i e t . O b s id ian o f p o s s ib ly Mayo rI s land o r ig in i l u s t ra te se a r ly a c ce s st ot h is r e sou rce . T he r a d ioca rbon d a ta f r om K okohu ia i mp l ie s o ccupa t ion o n t h i s a r ea o f t h e r i dge w a s s ho r t ( w i th in 1 00 y ea r s , a nd p o ss ib ly w i th in 5 0 y ea r s ) , e ven t h ough t h e re w a s al a rge a moun t o fc u l tu ra l ma te r ia l r e cove r ed f r om e xcava t ion . T h is b r ief o ccupa t ion a s soc ia ted w i th e x ten s ive m idden d epo s i t s i ss im i la r t ot h a t f ound a tS hag Mou th i nt h e S ou th I s land ( Ande r son e ta l . 1 996 ) . T h is e v idence m ay i l u s t ra te t ha t i mpac t u pon l o ca l r e sou rce s o ve r as hor t p e r iod o ft ime a t K okohu ia c on t r ibu ted t o s udden a bandonmen t . T h is s i te a ppea r sn o tt oh ave b een r e -occup ied u n t i lh i s to r ic t ime s .

1 09

T he r a d ioca rbon d a ted a r chaeo log ica l s i t e s o n P onu i I s land , i l us t ra te i t s l o ng t e rm o ccupa t ion i n N ew Z ea land p r eh i s to ry . O ccupa t ion o n P onu i a ppea r s t o h ave b egun i n t h e l a te 1 4 th c en tury AD , a s i n d ica ted a t S i te 1 43° . T h roughou t t h e i s land 's p r eh is to ry , t h e re w a s g r ea t c on t inu i ty i n t h e s ub s is tence a c t iv i t ie s p r ac t ised b y t h e p r eh is to r ic i n hab i tan t s . S he l lf i sh s p ec ie s p r e sen t t oday w e re a va i lab le a nd e xp lo i ted a t mo s t o ft h e s i te s . T hough s he l lf i sh a ppea r t ob e t h e p r ima ry f ood s ou rce a tt h e s amp led s i t e s , S i te 1 4 i l u s t ra te s t h e i mpor tance o f f i sh ing t o t h e i s l and 's i n hab i tan t s . P ag ru s a ura tus w a s t h e d om inan t f i sh s p ec ie s t a ken a t t h i s l o ca t ion . S hawc ro s s ( 1972 :594 ) a l so f o und P ag ru s a u ra tu s t ob e t h e mo s t c ommon ly c augh t s pec ie s i n G a la tea B ay t ot h en o r th o fS i te 1 4 . F ew a r t ef ac t s w e re f o und i nt h e s i t e s s amp led f o rt h is s t udy , b u t s i te N 43 /333 i n d ica te s t h a t a dze s w e re b e ing u sed a nd m ade , a nd p o s s ib ly c l o th ing m anuf ac tu r ed a ss e en i nt h e p re sence o f ab i rd -bone a w l . T he o b s id ian r e cove red f r om s i te N 43 /333 a l so s how s t h e a va i lab i l i ty o f Mayo r I s land a nd C o romande l P en in su la o b s id ian s ou rce st ot h e i s land s i n hab i tan t s i nt h e 1 5 th c en tu ry AD . T he a r chaeo log ica l s i te s i n L iga r B ay a nd a t S awp i t P o in t w e re b o th o ccup ied i n t h e m id 1 5 th c en tury AD , a nd i l u s t ra te a n e mpha s i s u pon l o ca l m a r ine r e sou r ce s i n p r eh i s to r ic s ub s i s tence . O n ly o ne a dze f l ake w a s f ound a tt h e L iga r B ay s i te s , b u t t h i s d oes i n d ica te t h a t a dze s w e re b e ing m anuf ac tu r ed f r om s t one r e sou r ced p o s s ib ly f r om D 'Urv i l le I s land s ome 7 5 km e a s t . T he S awp i t P o in t s i te s how s t h a t f o re s t b i rd s pec ies w e re h un ted u s ing b i rd s pea r s , t h ough o n ly C a l laea s c i nera w a s i d en t if ied . Mamma ls e xp lo i ted i n c luded R a t tu s e xu lan s , C an i s f am i l ia r i s a nd D e lph inu s d e lph i s . A s f ound a t K okohu ia , d og a ppea r s t o b e a n i mpor tan t m amma l ian c omponen t i nt h e p r eh is to r ic d i e t a t t h i s t ime . P r eh i s to r ic o ccupa t ion f r om L iga r B ay a nd a l ong t h e G ran i te C oa s t a ppea r s t o h ave b een c on t inuou s s i nce P o lyne s ian c o lon isa t ion c a . t h e 1 3 th c en tury AD , a s

P rof . G . I r w in o ft h e U n ive r s i ty o fA uck land D epa r tmen to f A n th ropo logy h a s r e cen t ly i d en t if ied a n a r cha eo log ica l s i te ( S I 1 / 20 )o n P onu i I s land c on ta in ing moa b one . 3 0

D iscuss ion a nd C onc lus ions

C II APTER 8

C ha r coa l h a s t h e a dvan tage o f a m ea su red t e r re s t r ia l c a l ib ra t ion c ur ve a s o pposed t ot h e mode l led m a r ine c u rve . H oweve r , t h e a moun t o f c ha r coa l d e r ived f r om s ho r t l ived m a te r ia l i so f ten v e ry l ow a nd t h e p o s s ib i l i ty o f i n bu i l t a ge s t i l l n eed st ob ec ons ide red .

i l us t ra ted b y t h e A rcha ic a r t if ac tua l ma te r ia l f r om Wa i rau B a r w he re moa w a s am a jo r p a r t o fs ub s is tence ( Duf f 1 950 ; 1 956 ; s e e C ha l l is 1 99 1 :10 1142 ) . T he d a t ing f r om L iga r B ay a nd S awp i t P o in t s how o ccupa t ion o f t h e n or thern w e s tern c oa s t l ine o ft h e S ou th I s land f r om a tl e a s t t h e 1 5 th c en tury , u n t i l t h ea r r iva lo fT a sman i n1 642 . CONCLUS IONS T he r e sea rch p re sen ted i nt h is d i s ser ta t ion l e ads s uppo r t t o t h e f o l low ing c onc lus ions : 1 )

A t l e a s tn i ne ma r ine s he l l s p ec ie sa r e r e l iab le f o r r ad ioca rbon d a t ing N ew Z ea land a r chaeo log ica l s i te s . T he se a r e : A u s t rovenu ss t u tchbu ly i , P aph ie sa u s t ra l i s , V ene rup i sl a rg i l l ie r t i , P aph ie ss ub t r iangu la tum , C om ine l la a d sper sa , C om ine l la v i rga ta , C ra s so s t rea g lome ra ta , L une I la s ma ragda a nd P erna c ana l icu lu s ;

2 )

C ha rcoa l i d en t if ied t ot w ig so fs ho r t l ived s pec ie s w i l l p rov ide c ompa ra t ive d a t ing m a te r ia lt om a r ine s he l l , t hough i n bu i l ta ge c an e f f ec tr e p roduc ib i l i ty . I nbu i l ta ge m ay p o s s ib ly b er e duced i ft w ig s f r om t r ee a nd s h r ub s pec ie su sed w h i le g r een b y p r eh is to r ic Mao r i a r e c ho sen f o rd a t ing ;

3 )

H a rdwa te ri sn o t ap o ten t ia l s ou rce o fe r ro rf o r r a d ioca rbon d a t ing s he l l f r om t h eN ew Z ea land a r chaeo log ica l s i te se xam ined a tt h e l e ve lo fp r ec is ion u sed i nt h is s t udy ;

4 )

T he m ix ing o fn a tu ra l ly -de r ived s he l l a nd c u l tu ra l m a te r ia l , a nd p o s t -depo s i t iona l d i s tu rbance a r e p robab le r e a sons f o r ma r ine s he l la ge a noma l ie s n o ted b y r e sea r che r s i nt h e p a s t . H oweve r , m ix ing o fn a tu ra la nd c u l tu ra lm a te r ia l a ppea r st ob er a re , a nd p o s t d epo s i t iona ld i s tu rbance s hou ld b ea b le t ob e d e tec ted i n t h ef i e ld b ya r chaeo log is t s ;

5 )

T he S tu ive ra nd B ecke r( 1993 ) mode l led m a r ine c u rve d oe sp rov ide a ccu ra te a nd p r ec i se c a l ib ra ted a ge s f o r a r chaeo log ica lm a r ine s he l l CRA , a nd i sa pp l icab le f o r N ew Z ea land p reh is to ry ;

6 )

T he c ur ren t. AR v a lue f o rN ew Z ea land o f25 ± 1 5y ea r s B P( H igham a nd H ogg 1 995 ) i sa pp l icab le f o rt h e c a l ib ra t ion o f ma r ine s he l l CRA u s ing t h e mode l led m a r ine c urve ;

7 )

T he re h a sb een n od e tec tab le t empo ra l v a r ia t ions i n AR o ve rt h ep a s t7 00 y ea r s f o rN ew Z ea land ;

8 )

N ew Z ea land a r chaeo log ica l s i t e sw i th a ccep tab le p a i r ed c ha rcoa la nd ma r ine s he l l r a d ioca rbon a ge sa na ly sed i n t h is s t udy , i n d ica te N ew Z ea land w a sc o lon ised b yt h e 1 4 th c en tury AD , a nd p o s s ib ly d u r ing t h e 1 3 th c en tury AD .

T he se a dvan tage s o f u s ing m a r ine s he l l a r e , o f c ou r se , d ependen t u pon t h e n a tu re o f t h e a r chaeo log ica l s i te b e ing e xcava ted a nd t h e a va i lab i l i ty o f s amp le t y pe s . A n a r chaeo log ica l s i t e d om ina ted b y c ha r coa l w h ich c an b e s e en t o b e a bundan t i nt w ig s m ay b e o fb e t te r c ho ice f o r d a t ing , e spec ia l ly i n ar e g ion w he re d ecay o f w ood a f te r d ea th i s k nown t ob e r a p id . A r chaeo log ica l s i t e s s uch a sp a ,h oweve r , a r e o f t en f o und t ob e l a ck ing i nc ha r coa l , a nd m a r ine s he l l t h e ref o re m ay b e t h e mo re a t t rac t ive o p t ion . I na dd i t ion , t h e u se o f t h e m ode l led m a r ine c urve p rov ide s l e s s s p read i n c a l ib ra ted a ge r a nge s a tt h e c r uc ia l p o s t 1500 AD p e r iod o f N ew Z ea land p r eh i s to ry . When a noma l ie s i n r a d ioca rbon d a te s f r om a r chaeo log ica l s i te s o ccu r , t h e a r chaeo log is t h a s o f t en c r i t ic ised t h e r a d ioca rbon d a t ing t e chn ique ( c f D uf f 's c r i t ic i sm o f t h e r a d ioca rbon d a te s f r om T akehe V a l ley ( Chap te r 1 ) ) . Ih ave s ugge s ted t h a t t h e mo s t c ommon r e a son f o r a ge d i sc repanc ie sb e tween r a d ioca rbon d a te s f r om a r chaeo log ica l s i te s i n N ew Z ea land i si n l a rge p a r t d ue t o af a i lu re b y a r chaeo log i s t s t o t a ke i n to a ccoun t p o s t -depo s i t iona l d i s tu rbance . A r chaeo log ica l d epo s i t s a r e n o t n ece s sa r i ly s t a t ic , e spec ia l ly i fa n a r ea i s r e occup ied . A r chaeo log ica l s i te s w h ich a r e e xpo sed t oa ny t ype o fw a t e r a c t ion , s uch a s b each f r on t s , o ri fp a r t ia l ly s ubme rged a th i gh t i de , s hou ld b e c a r ef u l ly a pp roa ched w hen s amp led f o r r a d ioca rbon d a t ing . S i te s w h ich h ave b een p l oughed s hou ld a l so b e c ons ide red c au t ious ly . C lea r ly , t h e r e a r e m any v a r iab les w h ich s e rve t o i nf luence t h e a ccuracy o fr a d ioca rbon d e te rm ina t ions i na r chaeo logy . T he v a l id i ty o f ar a d ioca rbon d a te r e s t s b o th u pon t h e e f f or t a t tached t o a r chaeo log ica l e xcava t ion t e chn ique a nd t o l a bo ra to ry a na ly s i s . A r e l iab le p r eh i s to r ic c h rono logy f o r N ew Z ea land c a n o n ly b e o b ta ined t h rough t h e r i go rous i n ve s t iga t ion o fe r ro r s f r om b o th s ou r ce s .

T he se c onc lus ions i l u s t ra te t h a t m a r ine s he l l p rov ide s a n umbe r o f a dvan tage s f o r N ew Z ea land p r eh is to r ian s o ve r t h e u se o f o t he r s amp le t y pe s f o r r ad ioca rbon d a t ing . T he f i r s t a dvan tage i st h a t m a r ine s h e l l i s u b iqu i tous i n N ew Z ea land a r chaeo log ica l s i te s . S econd , t h e re a r e n o c on s i s ten t o f f se t s b e tween r ad ioca rbon d a te s o n t h e s he l lf i sh s pec ie s e xam ined i nt h i s t h e s is . T h i rd , t h a t r e c ry s ta l l isa t ion i sr a r e i n N ew Z ea land a r chaeo log ica l s amp les . F our th , t h a t c a l ib ra ted m a r ine s he l l a ge s c ompa r e w e l l w i th c a l ib ra ted c ha r coa l d a te s w hen c a l ib ra ted u s ing t h e m ode l led m a r ine c u rve .

10

B IBL IOGRAPHY

B arne s , R .D . , C a r low , P . , a nd O l ive , P . J .W . 1 993 . T he I nver tebra te s : a n ew s yn the s i s . B lackwe l l S c ien t if ic P ub l ica t ion s , Oxfo rd .

A i tken , M .J . 1 990 . S c ience -ba sed Da t ing i n A rchaeo logy . L ongman P au l , L ondon a nd N ew Y o rk . A l len , M . 1 994 . T he C h rono logy o fC oa s ta l Morphogene s is a nd H uman S e t t lemen t o n A i tu tak i , S ou thern C ook I s land s , P o lynes ia . R ad ioca rbon 3 6 ( 1) :59 -7 1 .

B e l lwood , P . , 1 973 . R ad ioca rbon d a tes f r om O takan in i . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t ter 1 6 (4 ) : 1 731 74 .

A l len , J . , a nd S . H o ldaway . 1 995 . T he c on tam ina t ion o f P l e is tocene r a d ioca rbon d e term ina t ions i n Aus t ra l ia . A n t iqu i ty 6 9 :10 1112 .

B e rge r , R . a nd Meek , N . 1 992 . R ad ioca rbon D a t ing o f A nodon ta i n t h e Mo jave R ive r B as in . R ad iocarbon 3 4 (3) :578 -584 .

Amb rose , W . , a nd G reen , R .C . 1 962 . O bs id ian D a t ing : P r e l im inary R e su l t s . N ew Z ea land A rchaeo log ica l A s soc ia t ion N ew s le t ter 5 ( 4 ) :247 -248 .

B es t , E . , 1 9 14 . T he P eop l ing o fN ew Z ea land . Man 1 4 :737 6 . B es t , E . , 1 9 16 . Mao r i a nd Ma ru iw i : n o tes o n t h e o r ig ina l i n hab i tan t so fN ew Z ea land a nd t h e i rc u l tu re ; o n t h e q ues t ion o fh ow t h a t c u l tu re a f f ec ted t h e l a te r -com ing Mao r i , a nd o n t h e e x i s tence i nt h ese i s les o fc us toms , a r t s , a nd a r tef ac t s n o t t r aceab le t o P o lyne s ia . T ran sac t ion s a nd P roceed ing s o ft h e N ew Z ea land I n s t i tu te 4 8 :435 -437 .

A nde r son , A . 1 973 . T he c onch io l in d a t ing m e thod . N ew Z ea land J ourna lo fS c ience 1 6 :553 -558 . A nde rson , A . 1 982 . AR ev iew o fE conom ic P a t ter n s Du r ing t h e A rcha ic P ha se i n S ou thern N ew Z ea land . N ew Z ea land J ourna lo fA rchaeo logy 4 : 45 -75 . A nde r son , A . 1 984 . T he E x t inc t ion o f Moa i nS ou thern N ew Z ea land . I n P . S . Mar t in a nd R .G . K le in ( ed s ) Qua ternary E x t inc t ion s : A P reh i s tor ic R evo lu t ion . T he U n iver s i ty o f A r izona P re s s , T ucson , A r izona .

B es t , E . , a nd A nde r son , J .C . 1 926 . A no the r Unknown A r t if ac t f r om Swamp L and . J ourna l o f t h e P o lyne s ian S oc ie ty 3 5 ( 137 ) :70 . B eavan , N .R . a nd S pa rks , R . J . 1 998 . F ac to r s I nf luenc ing ' 4C Ages o ft h e P ac if ic R a t R a t tu s e xu lans . R ad iocarbon 4 0 (2 ) : 6 0 1-6 13 .

A nder son , A . 1 989 . P rod ig ious B i rd s : Moa a nd Moa H un t ing i nP reh i s tor ic N ew Z ea land . C amb r idge U n ive r s i ty P ress .

B owman , S . 1 990 . I n terpre t ing t h e P a s t : R ad iocarbon Da t ing . B r i t ish Museum P ub l ica t ions L td . , L ondon . p p . 9 15 .

A nder son , A . 1 991 . T he C h rono logy o fC o lon iza t ion i nN ew Z ea land .A n t iqu i ty 6 5 :767 -795 .

B rod ie , J .W . 1 962 . A R econna i s sance o f Wa rehou P a , Maka ra . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t te r5 ( 3) : 156 159 .

A nder son , A .J . , 1 996 . R a t C o lon isa t ion a nd V oyag ing : a no ther h ypo thes is . R apa N u iJ ourna l 1 0 (2 ) :31-35 . A nde r son , A . , A l l ingham , B . , a nd Sm i th , I .1 996 . S hag R ive r Mou th : T he A rchaeo logy o f a n E ar ly S ou thern Maor i V i l lage . R esea rch p ape r s i nA rchaeo logy a nd N a tura l H is tory N o . 2 7 , ANH P ub l ica t ions , T he Aus t ra l ian Na t iona l U n ive r s i ty , C anber ra , A u s t ra l ia .

B ron ic , I . K . H orva t inc ic , N . , S rdoc , D . a nd Obe l ic , B . 1 99 1 . E xpe r imen ta l D e term ina t ion o f t h e ' 4C I n i t ia l A c t iv i ty o f C a lca reous D epo s i t s . R ad iocarbon 3(2 ) :181- 1 82 . B u is t , A .G . 1 962 . R ad ioca rbon A na lys is . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 5 (4 ) :249 -250 .

A nde r son , A .J . a nd McGovern -W i lson , R . 1 990 . T he P a t tern O f P reh is to r ic P o lyne s ian C o lon isa t ion i n N ew Z ea land . J ourna lR oya lS oc ie ty N ew Z ea land 2 0 (1) :4 1-63 . A ravena , R . , S ch if f , S .L . , T rumbo re , S .E . a nd D i l l ion , P . J . 1 991 . E va lua t ing D is so lved I no rgan ic C a rbon C yc l ing i na F o res ted L ake Wa te r shed U s ing C a rbon I s o tope s . R ad iocarbon 3 3 (2 ) :170 . B a rber , I . 1 994 . C u l ture C hange i n Nor thern T e Wa i P ounamu . U npub l ished P hD T hes is , D epa r tmen t o f A n thropo logy , U n ive r s i ty o fO tago , D uned in . B a rbe r , I . ,1 995 . C ons t ruc t ions o fC hange : AH is to ry o fe a r ly Mao r i C u l tu re S equence s . J ourna l o ft h e P o lyne s ian S oc ie ty 3 57 -396 .

C augh ley , G . 1 988 . T he C o lon isa t ion o fN ew Z ea land b y t h e P o lyne s ians . J ourna l o ft h e R oya l S oc ie ty o fN ew Z ea land 1 8 (3) :245 -270 . C ha l l is , A .J . , 1 99 1 . T he N e lson -Ma r lbo rough R eg ion : a n A rchaeo log ica l S yn the s is . N ew Z ea land J ourna l o f A rchaeo logy 1 3 :10 1-142 . C ha l l is , G .A . 1 978 . C re taceou s I gneou s R ock s -T ang ihua V o lcan ic s . I n R .P . S ugga te ( Ch ief E d .) T he G eo logy o fN ew Z ea land , V o lume I . N ew Z ea land G eo log ica l S urvey , D epa r tmen t o f S c ien t if ic a nd I ndus t r ia l R esea rch , We l l ing ton ,N ew Z ea land . p p . 6 28 . C l if ton , N .C . 1 990 . N ew Z ea land T imber s , E xo t ic a nd I nd igenou s : T he C omp le te Gu id e . Wr igh t & C a rmen L td . , Uppe rH u t t .

B arnes , R .D . 1 987 . I nver tebra te Z oo logy . CBS C o l lege P ub l ish ing , U n i ted S t a tes o f Ame r ica .

11

B IBL IOGRAPHY C ou t t s , J . F . 1 972 . T he U t i l i ty o f R ad io -Carbon D e term ina t ion s f or Da t ing N .Z . A rchaeo log ica l S i te s . P roceed ing s o f t h e 8 t h I n terna t iona l C onf e rence o n R ad ioca rbon D a t ing . p p . 5 16 -531

F l em ing , C .A . , a nd H a r r is , W .F . 1 978 . S ubd iv i s ion o ft h e Q ua ternary : P a laeon to log ica l S ubd iv i s ion -H awe ra S er ie s . I n R .P . S ugga te ( Ch ief E d . ) T he G eo logy o fN ew Z ea land , V o lume I . N ew Z ea land G eo log ica l S u rvey , D epa r tmen t o f S c ien t if i c a nd I ndus t r ia l R esea r ch , We l l ing ton , N ew Z ea land . p p . 5 49 -550 .

D amon , P .E . , L ong , A . a nd Wa l l ick , E . I . 1 972 . D end rochrono log ica l c a l ib ra t ion o f t h e C a rbon 14 t ime s ca le . I nP roceed ing s o ft h e 8 t h I n terna t iona l C onf erence o n R ad iocarbon Da t ing , L owe rH u t t , N ew Z ea land . p p . 4 5 -59 .

F l es sa , K .W . , C u t le r , A .H . a nd Me ldah l , K .H . 1 993 . T ime a nd t a phonomy : q uan t i ta t ive e s t ima te so ft ime -ave rag ing a nd s t ra t ig raph ic d i so rde r i n a s ha l low ma r ine h ab i ta t . P a leob io logy 1 9 (2 ) : 2 66 -286 .

D av idson , J .M . 1 984 . T he P reh i s tory o f N ew Z ea land . L ongman P au l , A uck land . D eevey , E .S . ( J r ) 1 984 . Z e ro B P P lus 3 4 : 2 5 Y ea r s o f R ad iocarbon . R ad iocarbon 2 6 ( 1) :1 6 . D ruf f e l , E .M . , a nd S ues s , H .E . 1 983 . O n t h e R ad ioca rbon R eco rd i n B anded C o ra ls : E xchange P a rame te r s a nd N e t T ran spor t o f ' 4CO 2 B e tween A tmosphe r ic a nd S urf ace

F l es sa , K .W . , a nd K owa lewsk i , M . 1 994 . S he l l s u rv iva l a nd t ime -ave rag ing i n n ea r s ho re a nd s he lf e nv i ronmen t s : e s t ima tes f r om t h e r a d ioca rbon l i t e ra ture . L e tha ia 2 7 :153 1 65 . F on te s , J . C . , A nd rews , J .N . , C aus se , C . a nd G iber t , E . 1 991 . A C ompa r ison o f ' 4C a nd U /Th A ges o n C on t inen ta l C a rbona tes . R ad ioca rbon 3 3(2 ) :1 96 197 .

O cean . J ourna l o fG eophy s ica l R e search V o l . 8 8 , n o . C 2 : 1 27 11280 . D ruf f e l , E .R .M . a nd W i l l iam s , P .M . 1 991 . R ad ioca rbon i n S eawa te r a nd O rgan isms f r om t h e P ac if ic C oa s t o f B a ja C a l if o rn ia . R ad iocarbon 3 3 (3 ) :29 1-296 . D uf f , R .S . 1 956 . T he Moa -hun ter P er iod o f Maor i C u l ture . Governmen t P r in te r , We l l ing ton . D uf f , R .S . 1 959 . N eo l i th ic Ad ze s o fE a s tern P o lyne s ia . I n J .D . F reeman a nd W .R . G edde s ( eds ) . A n thropo log y i n t h e S ou th S ea s : E s say s p re sen ted t o H .D . S k inner . T homa s A very & S ons L im i ted , N ew P l ymou th , N ew Z ea land . p p . 1 2 1147 .

F ox , A . 1 978 . T i romoana p a , T e Awanga , H awke ' sB ay , E xcava t ions 1 974 -5 . Monog raph 8 o f t he N ew Z ea land A rchaeo log ica l A s soc ia t ion . G a rc ia , J . F . , Mes t res , J . S . a nd R au re t , G . 1 99 1 . T he U se o f C on t inen ta l C a rbona tes C ompa red w i th O the r Ma te r ia ls i n t h e D a t ing o f aP a leo lake . R ad iocarbon 3(2) :198 199 . G i l le sp ie , R . , a nd P o lach , H .A . 1 979 . T he S u i tab i l i ty o f Mar ine S he l l s f or R ad iocarbon Da t ing A u s tra l ian P reh i s tory . I n R . B e rge r a nd H .E . S ue s s ( eds .) R ad iocarbon Da t ing . P roceed ing s o ft h e 9 th I n ter na t iona l C onf e rence o n R ad ioca rbon D a t ing . U n ive r s i ty o fC a l if or n ia P re s s . p p . 4 04 4 21 .

D uf f , R .S . 1 96 1 . E xcava t ion o fH ouse -p i t s a tP a r i Whaka tau P a , C lave r ly , Ma r lbo rough . R ecord s o f t h e C an terbury Mu seum 7 (4 ) :269 -302 . D uf f , R .S . 1 962 . A spec t s o f t h e C u l tu ra l S uccess ion i n C an te rbury -Ma r lbo rough w i th W ide r R ef e rence t ot h e N ew Z ea land A rea . N ew Z ea land A rchaeo log ica l A s soc ia t ion N ew s le t ter 5 (4 ) :205 -209 . D ye , T . 1 990 . Ma r ine T ur t le B one s F rom a n A rchaeo log ica l S i te i n P o lynes ia Y ie ld R e l iab le Age D e term ina t ion s . R ad iocarbon 3 2 (2 ) :143 147 ) . D ye , T . 1 994 . A ppa ren t A ge s o f Ma r ine S he l ls : I mp l ica t ions f o rA rchaeo log ica l D a t ing i nH awa i i . R ad iocarbon 3 6 ( 1) :515 7 . E lzenaa r , N . 1 994 . Obs id ian S ourc ing , Whangapoua , G rea t B a rr ier I s land : A rea s A , B , Macrocarpa F a l l & M i sce l laneous F ind s . 0 3 .340 F ie ld S choo l , F eb . 1 994 . F i e ld S choo l A ss ignmen t P ape r 0 3 .340 , D epar tmen t o f A n thropo logy , U n ive r s i ty o fA uck land , A uck land . F aco re l l is , Y , Man ia t is , Y . a nd K rome r , B . 1 998 . A ppa ren t " C Ages o f Ma r ine Mo l lu sk S he l ls f r om a G reek I s land : C a lcu la t ion o f t h e Ma r ine R e se rvo i r E f f ec t i n t h e A egean S ea . R ad ioca rbon 4 0 (2 ) : 9 63 -973 .

G lynn , P .W . , D ruf f e l , E .M . a nd D unba r , R .B . 1 983 . Ad ead C en t ra l Amer ican c o ra l r e ef t r ac t : P o s s ib le l i nk w i th t h e L i t t le I c e Age .J ourna lo f Mar ine R e sea rch 4 1 :605 -637 . Go lson , J . 1 955 . D a t ing N ew Z ea land 's P reh is to ry . J ourna l o ft h eP o lynes ian S oc ie ty 6 4 :113-136 . Go lson , J . , 1 959 . C u l ture C hange i n P reh i s tor ic N ew Z ea land . I n J .D . F reeman a nd W .R . G edde s ( eds ) . A n thropo logy i n t h e S ou th S ea s : E s say s p resen ted t o HD . S k inner . T homa s A ve ry & S ons L im i ted , New P l ymou th , N ew Z ea land . p p . 2 9 -74 . Go lson , J . , 1 986 . O ld G ua rds a nd N ew Waves : R ef lec t ions o n A n t ipodean A rchaeo logy . A rchaeo logy i n O cean ia 2 1 :2 1 2 . Go rdon , J . a nd H a rkness , D .D . 1 993 . Magn i tude a nd G eog raph ic V a r ia t ion o f t h e R ad ioca rbon C on ten t i n An ta rc t ic Ma r ine L if e : I mp l ica t ion s f o r R e se rvo i r C or rec t ions i n R ad ioca rbon D a t ing . Q ua ternary S c ience R ev iew s Vo l . 1 : 6 97 -708 . G ran t -Tay lo r , T .L . 1 974 . R ad ioca rbon D a t ing . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 1 7 :157 -162 . G reen , R .C . 1 962 . O b s id ian : I t s App l ica t ion t oA rchaeo logy . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t te r 5 ( 1) :8 1 6 .

F ankhause r , B . 1 992 . D a t ing E a r th O vens w i th T hermo lum ine scence a nd R ad iocarbon . P ape r s p resen ted t o t h e Q ua terna ry D a t ing Wo rk shop , R e sea rch S choo l o f P ac if ic S tud ie s , A us t ra l ian N a t iona l U n ive r s i ty , C anbe r ra , O c tober 1 990 .

G reen , R .C . 1 967 . S ource s o f N ew Z ea land 's E a s t P o lyne s ian C u l ture : T he E v idence o f aP ea r l S he l l L u re

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B IBL IOGRAPHY H ay , R .F . 1 978 . C re taceous S t ra t ig raphy -Ma ta S er ie s . I n R .P . S ugga te ( Ch ief E d .) T he G eo logy o f N ew Z ea land , V o lume I . N ew Z ea land G eo log ica l S urvey , D epar tmen t o f S c ien t if ic a nd I n dus t r ia l R esea rch , We l l ing ton , N ew Z ea land . p p . 3 67 -368 .

S hank . A rchaeo logy a nd P hy s ica lA n thropo logy i n O cean ia 2 (2 ) : 8 1-90 G reen , R .C . a nd F .W . S hawc ro s s . 1 96 1 . C u l tu ra l S equence i n t h e A uck land P rovenance . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t te r5 (4 ) :210 -220 .

H e ie r -N ie lsen , S .H . , H e ineme ie r , J . , N ie lsen , H .L . a nd R ud , N . 1 995 . R ecen t R e se rvo i r Ages f o r D an ish F io rds a nd Ma r ine Wa te r s . R ad ioca rbon 3 8 (2 ) : .

G rey , C . 1 994 . 0 3 .340 R epor t : P ar t I T ex t , P ar t I I l lus tra t ion s . F ie ld S choo l A ss ignmen t P aper 0 3 .340 . D epa r tmen t o f A n th ropo logy , U n ive r s i ty o f A uck land , Auck land .

H igham , T .F .G . 1 993 . R ad iocarbon Da t ing t h eP reh i s tory o f N ew Z ea land . U npub l ished P hD T he s is , Un ive r s i ty o f Wa ika to , H am i l ton .

G r ind ley , G .W . 1 971 . S hee t S 8 - T akaka ( 1 s t e d .) . G eo log ica l Map o fN ew Z ea land 1 :63 ,3600 . D epar tmen t o f S c ien t i f ic a nd I ndus t r ia l R esea rch , We l l ing ton , N ew Z ea land . G r ind ley , G .W . , 1 978 . I n trus ive R ock s : W e s tN e l son . I n R .P . S ugga te ( Ch ief E d . ) T he G eo logy o fN ew Z ea land , V o lume I . N ew Z ea land G eo log ica l S urvey , D epa r tmen t o f S c ien t if ic a nd I ndus t r ia l R esea rch , We l l ing ton , N ew Z ea land . p p .95 9 6 . f i g . 2 . 13 . G roube , L .M . 1 970 . T he O r ig in a nd Deve lopmen t o f E ar thwork F or t if i ca t ion s i n t h e P ac if i c . I n R .C . G reen a nd M . K e l ly ( e d s ) S tud ie s i n O cean ic C u l ture H i s tory , Vo l . 1 PAR 1 , B i shop Museum , H ono lu lu . p p . 1 33 -164 . G roube , L .M . , 1 993 . ' D ig u p t h o se moa b one s , d ig ' : Go l son i n N ew Z ea land , 1 954 -1961 . I n M . S p r igg s e t a l . ( eds ) A C ommun i ty o fC u l ture : T he P eop le a nd P reh i s tory o ft h e P ac i f ic . D epar tmen t o f P reh is tory , R esea rch S choo l o f P ac if ic S t ud ies , T he Aus t ra l ian N a t iona l U n iver s i ty , C anber ra , A us t ra l ia . p p . 6 17 . Gup ta , S .K . a nd P o lach , H .A . 1 985 . R ad iocarbon Da t ing P rac t ice s a t ANU . H andbook , R ad ioca rbon L abo ra to ry , R esea rch S choo l o f P ac if ic S tud ies , A us t ra l ian N a t iona l Un ive r s i ty , C anber ra .

H igham , T .F .G . 1 994 . R ad ioca rbon D a t ing N ew Z ea land P reh is tory W i th Moa E gg she l l : S ome P r e l im ina ry R esu l t s . Qua ternary G eochrono logy ( Qua terna ry S c ience R ev iew s ) Vo l . 1 3 p p . 1 63 169 . H igham , T .F .G . , a nd H ogg , A .G . 1 995 . R ad ioca rbon d a t ing o fp reh is to r ic s he l l f r om N ew Z ea land a nd c a lcu la t ion o ft h e AR v a lue u s ing f i sh o t o l i ths . R ad iocarbon 3 7 (2 ) : 4 09 -4 16 . H ja rno , J .1 967 . Mao r i f i sh -hook s i ns ou the rn N ew Z ea land . R ecord s o ft h eO tago Museum ( An thropo logy ) No . 3 . Hogg , A . 1 982 . R ad iocarbon Da t ing a t t h e U n iver s i ty o f Wa ika to , N ew Z ea land . O cca s iona l R epor t N o . 8 , D epar tmen t o f E a r th S c ience s , U n ive r s i ty o f Wa ika to , H am i l ton . Hogg , A . , P o lach , H . , R ober t son , S . , a nd Noakes , J . 1 99 1 . A pp l ica t ion o fH igh P ur i ty S yn the t ic Q uar t z V ia l s t oL iqu id S c in t i l la t ion L ow -Leve l C C oun t ing o fB en zene . I nH . R os s , J . E . Noake s a nd J .D . S pau ld ing ( eds ) , L iqu id S c in t i l la t ion C oun t ing a nd O rgan ic S c in t i l la tor s . L ew i s P ub l ishe r s , I NC . M ich igan , USA . 1 4

Hogg , A .G . , L owe , D . J . a nd H endy , C .H . 1 987 . U n ive r s i ty o f Wa ika to R ad ioca rbon D a te s I .R ad iocarbon 2 9 (2 ) :263 3 01 .

H aas t , J .1 875a . R e sea rches a nd e xcava t ions c a r r ied o n , i n a nd n ea r Moa B one P o in t C ave , S umne r R oad i n t h e y ea r 1 872 . T ran sac t ion s o ft h eN ew Z ea land I n s t i tu te 7 : 54 -85 .

Ho ldaway , R . 1 996 . No T i t le . P ape r p resen ted o n r ad ioca rbon a ge s o n K io re ( Ra t tus e xu lans ) b one , a t D epar tmen t o f A n thropo logy S em ina r , U n ive r s i ty o f Auck land , J une 1 .

H aa s t , J .1 875b . No te s o n a n a nc ien t n a t ive b u r ia l p l ace n ea r t h e Moa B one P o in t C ave , S umne r . T ran sac t ion s o ft h eN ew Z ea land I n s t i tu te 7 : 98 -9 1 . Haa s t , J . 1 875c . No te s o n t h e Moa -hun te r e ncampmen t a t S hag P o in t , O tago . T ransac t ion s o f t h e N ew Z ea land I ns t i tu te 7 : 9 1-98 .

Hun t , T .L . a nd K i rch , P .V . 1 987 . R ad ioca rbon D a te s f r om Two C oa s ta l S i tes i nt h e Manu 'a G roup , Ame r ican S amoa . R ad iocarbon 2 9 (3) : 4 17 -419 . I ng ram , B .L . 1 994 . C Mea suremen t s i n C harcoa l -She l l P a ir sf rom I nd ian M idd ens f rom S an F ranc i sco B ay : P a /co U pw e l l ing V a r ia t ion s A long t h e Nor th Amer ican C oa s t . Abs t rac t , 1 5 th I n ter na t iona l R ad ioca rbon C onf e rence , p p . P E -1 I . 1 4

H a jda s , I . , B ee r , J . , B onan i , G . , L o t te r , A . , S turm , M . a nd Wo lf l i , W . 1 991 . ' 4C M ea su remen t s o n L am ina ted L ake S ed imen t s . R ad iocarbon 3 3 (2 ) :205 -206 . Hame l , G . 1 978 . R ad ioca rbon d a te s f r om t h e moa -hun te r s i te o f P apa towa i , O tago , N ew Z ea land . N ew Z ea land A rchaeo log ica lA s soc ia t ion N ew s le t ter 2 1( 1) :53 -54 . H a r low , D . 1 994 . A o tea /Grea t B a r r ier I s land -A H i s tory : A r ev iew o ft h e Mao r ia nd P akeha h i s tory o ft h e i s land w i th a f ocus o n Maor it r ad i t iona lh i s tor ie s , i ndu s t r ie s o nA o tea a nd t he W hangapoua a rea . F ie ld S choo l A s s ignmen t P aper 0 3 .340 . D epar tmen t o f A n th ropo logy , U n ive r s i ty o f Auck land , A uck land .

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I ng ram , B .L . a nd S ou thon , J .R . 1 996 . R e se rvo ir Age s i nt h e E a s tern P ac if ic C oa s ta l a nd E s tua r ine Wa te r s . R ad iocarbon 3 8 (3) : 5 73 -582 . J ansen , H .S . 1 984 . I n s t i tu te o fN uc lear S c ience s I NS -R -328 R ad iocarbon Da t ing f or C on tr ibu tor s . I n s t i tu te o f N uc lea r S c iences , D S IR , L owe rH u t t . K a shga r ian , M . , S u l l ivan , T .W . a nd S ou thon , J .R . 1 994 . R eservo i rA ge s o fS urf ace Wa ter s i nt he I ndone s ian S eaway .

B IBL IOGRAPHY L ong , A . 1 995 . F rom t h e E d i to r : G ood -bye t o P ee D ee B e lemn i te a nd S tanda rd Mean O cean Wa te r ; N IST S t anda rd N omenc la tu re . R ad iocarbon 3 7 ( 1) : i .

A bs t rac t , 1 5 th I n terna t iona l R ad ioca rbon C onf e rence , p p C 1 0 . K ea r , D . a nd H ay , R .F . 1 96 1 . S hee t I-N or th C ape ( 1 s te d) . G eo log ica l Map o fN ew Z ea land 1 : 250 ,000 . D epar tmen t o f S c ien t if ic a nd I ndus t r ia l R esea rch , We l l ing ton , N ew Z ea land .

L owe , D .J . , a nd H ogg , A .G . 1 992 . A pp l ica t ion o f n ew t e chno logy l i qu id s c in t i l la t ion s pec t rome t ry t o r a d ioca rbon d a t ing o f t e phra d epo s i t s , N ew Z ea land . Q ua ternary I n terna t iona l 1 3 / 14 :135 142 .

K er r , S .W . 1 994 . Whangapoua -G rea t B ar r ier I s land : A n A na ly s i s o fF i sh B one E xcava ted f rom S i te sS 8 / 171 & S 8 / 16 . F ie ld S choo l A ss ignmen t P ape r 0 3 .340 . D epar tmen t o f A n th ropo logy , U n ive r s i ty o fA uck land , A uck land .

Mangerud , J . 1 972 . R ad ioca rbon d a t ing o f ma r ine s he l ls i n c lud ing ad i scuss ion o fa ppa ren t a ge o fr e cen t s he l ls f r om N o rway . B orea s 1 : 143 172 . Mangerud , J .a nd G u l l ik sen , S . 1 975 . A ppa ren t R ad ioca rbon A ges o f R ecen t Ma r ine S he l ls f r om N orway , S p i t sbergen , a nd A r t ic C anada . Qua te rnary R e search : A n I n terd i sc ip l inary J ourna l5 ( 2 ) : 2 63 -273 .

K i rch , P .V . a nd H un t , T .L . 1 988 . R ad ioca rbon D a te s f r om t h e Mus sau I s lands a nd t h e L ap i ta C o lon iza t ion o ft h e S ou th We s te rn P ac if ic . R ad iocarbon 3 0 (2 ) :16 1-169 . K irch , P .V . , H un t , T .L . a nd T y le r , J . 1 989 . A R ad ioca rbon S equence f r om t h e T oaga S i te , O f u I s land , Ame r ican S amoa . R ad ioca rbon 3 1( 1) :7 -13 .

Ma rchenko , E . , S rdoc , D . , G o lub ic , S . , P ezd ic , J .a nd H ead , M .J . 1 989 . C a rbon u p take i n a qua t ic p l an t s d educed f r om t h e ir n a tura l ' 3C a nd ' 4C C on ten t . R ad iocarbon 3 1(3) :785 7 94 .

L aw , G . 1 971 . S ome E r ro r s w i th C a rbon 14 D a t ing . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 1 4 :64 -66 L aw , G . 1 975a . R ad ioca rbon D a tes f r om R ang i to to a nd Mo tu tapu , aC ons ide ra t ion o f t h e D a t ing A ccuracy . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t ter 1 8 (4 ) :4414 51 .

McCormac , F .G . , H ogg , A .G . , H igham , T .F .G . , B a i l le , M .G .L . , P a lme r , J .G . , X iong , L . , P i lcher , J .R . , B rown , D . , a nd Hope r , S .T . 1 998 . V a r ia t ions o f R ad ioca rbon i n T ree R ing s : S ou thern H em i sphe re O f f se t P re l im ina ry R esu l t s . R ad iocarbon 4 0 (3) : 153 1159 .

L aw , G . 1 975b . C 14 D a tes f r om H a ra taonga B ay , G rea t B ar r ie r I s land . N ew Z ea land A rchaeo log ica l A s soc ia t ion N ew s le t ter 1 8 ( 1) :48 -52 .

McCu l loch , B . 1 973 . A R e levan t R ad ioca rbon R esu l t ( I r reve ren t ly P resen ted ) . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t ter 1 6 :128 -133 .

L aw , G . 1 981 . R ad ioca rbon D a t ing , S ome G u idance f o r U se r s . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t ter 2 4 :228 -236 .

McCu l loch , B a nd T ro t te r , M .M . 1 975 . T he F i r s t Twen ty Y ea r s . R ad ioca rbon D a te s f o r S ou th I s land Moa -Hun te r S i tes , 1 955 1974 . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t ter 1 8 :2 -17

L aw , G . 1 984 . A rchaeo log ica lC arbon D a t ing U s ing Mar ine S he l l -T he N ew Z ea land E xpe r ience . P ape r p r esen ted a t N ew Z ea land A rchaeo log ica l A s soc ia t ion C onf e rence , J une 1 984 . L each , B .F . 1 967 . Memo randum f r om M . T ro t te rt oR . D uf f . H e ld i n t h e D epar tmen t o f A n th ropo logy , U n ive r s i ty o f O tago , D uned in . L ibby , W .F . , A nde r son , E .C . , a nd Ar no ld , J .R . 1 949 . Age d e term ina t ion b y R ad ioca rbon c on ten t : wo r ld -w ide a s say o f n a tu ra l r a d ioca rbon . S c ience 1 09 :227 -28 .

McFadgen , B . 1 972 . P a leoenv i ronmen ta l s t ud ie s i n t h e Manawa tu s and p la in w i th p ar t icu la r r ef erence t o F ox ton . U npub l ished MA t h e s is , D epa r tmen t o f An th ropo logy , U n iver s i ty o fO tago . McFadgen , B . 1 978a . E nv i ronmen t a nd a rchaeo logy i nN ew Z ea land U npub l ished P hD t h es is , D epa r tmen t o f G eo logy , V ic tor ia U n ive r s i ty , We l l ing ton . McFadgen , B . 1 978b . R ad ioca rbon i n Modern Ma r ine S he l ls C ompa red w i th t he N ew Z ea land S t anda rd . N ew Z ea land J ourna lo fS c ience 2 1 :311-313

L i t t le , E .A . 1 993 . R ad ioca rbon A ge C a l ib ra t ion a t A rchaeo log ica l S i tes o fC oa s ta l Ma ssachu se t t s a nd V ic in i ty . J ourna lo fA rchaeo log ica lS c ience 2 0 :457 -471 .

McFadgen , B . 1 982 . D a t ing N ew Z ea land A rchaeo logy b y R ad ioca rbon .N ew Z ea land J ourna lo fS c ience 2 5 :379 -392 .

L ocke rb ie , L . 1 959 . F rom Moa -Hun te r t o C la s s ic Mao r i i n S ou ther n N ew Z ea land . I n J .D . F reeman a nd W .R . G eddes ( eds ) . A n thropo logy i n t he S ou th S ea s : E ssay s p re sen ted t o H .D . S k inner . T homa s Avery & S on s L im i ted , N ew P lymou th ,N ew Z ea land . p p . 7 5 -110 .

McFadgen , B .G . , K nox , F .B . a nd C o le , T .R .L . 1 994 . R ad ioca rbon C a l ib ra t ion C u rve V a r ia t ions a nd t h e ir I mp l ica t ion s f o r t h e I n terp re ta t ion o f N ew Z ea land P reh is tory . R ad iocarbon 3 6 (2 ) :221-236 .

L ocke rb ie , L . 1 980 . C or respondence b e tween I n s t i tu te o f Nuc lea r S c iences a nd L es L ocke rb ie o ft h e O tago Museum r ega rd ing r a d ioca rbon d a t ing o f P ounawea a r chaeo log ica l s i te b e tween 1 957 a nd 1 980 . F i le r e f e rence R 4544 / 1-9 , R 9 180 , I n s t i tu te o f G eo log ica l a nd N uc lea r S c iences , L owe r H ut , We l l ing ton .

McFadgen , B .G . a nd Mann ing , M .R . 1 990 . C a l ib ra t ing N ew Z ea land R ad ioca rbon D a te s o f Ma r ine S he l ls . R ad iocarbon 3 2 (2 ) :229 -232 . McGh ie , M .D . 1 994 . AR epor t o n t h e Da t ing o fO bs id ian A r tef ac t s f rom Whangapoua - G rea t B a r r ier I s land , a nd S ome A na ly s i so ft he R e su l t s . F ie ld S choo lA ss ignmen tP aper 0 3 .340 . D epa r tmen t o f A n thropo logy , U n ive r s i ty o f A uck land , A uck land .

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B IBL IOGRAPHY M i l l igan , E .N . 1 959 . T he G eo logy o ft h e N or th Hok ianga D i s t r ic t . MSc T hes is , D epa r tmen t o fG eo logy , U n ive r s i ty o f A uck land , A uck land . Moo re , P .R . a nd T i l ler , E .M . 1 975 . R ad ioca rbon D a te s f o r N ew Z ea land A rchaeo log ica l S i te s . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 1 8 :98 -107 Moo re , P .R . a nd T i l ler , E .M . 1 976 . R ad ioca rbon D a tes f o r N ew Z ea land A rchaeo log ica l S i tes : e r ra ta a nd a ddenda . N ew Z ea land A rchaeo log ica lA s soc ia t ion N ew s le t ter 1 9 :151-155 .

AMS d a t ing a nd i o n b eam a na lys is . N uc lear I n s trumen t sa nd Me thod s , B 29 :270 -273 . R i ley , M . 1 993 . Maor i H ea l ing a nd H erba l . V ik ing S even S ea P ub l ica t ions , P a rapa raumu . R ow land , M .J . 1 976 . C e l lana d en t icu la ta i nM iddens o n t h e C o romande l C oa s t , N .Z . , -P o ss ib i l i t ie s f o r a T empo ra l H o r izon . J ourna l o ft h e R oya lS oc ie ty o fN ew Z ea land 6 ( 1) : 1 15 . R omanes , J .R . , 1 993 . I s land i nt h es un: G IS , a nd a mod e lo f t h e p reh i s tor ic a g r icu l tura lp o ten t ia l o fP onu i I s land , N ew Z ea land . R e sea rch e s say , D epar tmen t o f A n thropo logy , U n ive r s i ty o fA uck land .

Mor ton , J .a nd M i l ler , M . 1 968 . T he N ew Z ea land S ea S hore . C o l l ins , Auck land . O eschge r , H . , S iegen tha le r , U . , S cho l le re r , U . a nd G uge lmann , A . 1 975 . A b ox d i f f u s ion mode l t o s t udy t h e c a rbon d iox ide e xchange i nn a tu re . T e l lu s2 7 :168 -192 .

S a lmon , J .T . 1 992 . T he N a t ive T ree s o fN ew Z ea land . R eed B ooks , Auck land . S chm id t , M .D . 1 993 . F ew Have B een T e s ted b y t he S pad e : P a e xcava t ion a nd r ad iocarbon d a t ing i n N ew Z ea land a rchaeo logy . MA R esea rch P ape r , D epa r tmen t o f A n th ropo logy , U n ive r s i ty o fA uck land , A uck land .

O lsson , I . U . 1 983 . Da t ing n on te rre s t r ia l ma ter ia l s . Manuscr ip t h e ld a t U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra tory , H am i l ton . O 'Regan , G . , 1 992 . T he A n t iqu i ty o f t h e T akahe V a l ley R ock S he l te r S i te . A rchaeo logy i nN ew Z ea land 3 5 (3) :172 1 76 ) .

S chm id t , M .D . 1 996a . T he c ommencemen t o f p a c ons t ruc t ion i n N ew Z ea land p reh is to ry . J ourna l o f t h e P o lyne s ian S oc ie ty .

P e tchey , F . 1 998 . R ad iocarbon A na ly s i s o f a Nove l B one S amp le T ype : S napper a nd B ar racou ta B one f rom N ew Z ea land A rchaeo log ica l S i te s . U npub l ished P hD T hes is , U n iver s i ty o f Wa ika to , H am i l ton .

S chm id t , M .D . 1 996b . R ad iocarbon Da t ing N ew Z ea land P reh i s tory U s ing Mar ine S he l l . U npub l ished P hD T hes is , U n ive r s i ty o f Wa ika to , H am i l ton . S chm id t , M .D a nd H igham , T .F .G . 1 998 . O r ig ins o f N ew Z ea land 's A rcha ic E a s t P o lynes ian c u l tu re r ev is i ted : T he c h rono logy o ft h e T a irua a r chaeo log ica l s i te . J ourna l o ft h e P o lyne s ian S oc ie ty 1 07 (4 ) : 3 95 -403 .

P he lan , M .B . , 1 999 . A AR C o r rec t ion V a lue f o r S amoa f r om K nown -Age Ma r ine S he l ls . R ad iocarbon 4 1(1) : 9 9 -101 . P o lach , H .A . 1 992 . F our D ecad e s o fP rog re s s i n C Da t ing b y L iqu id S c in t i l la t ion C oun t ing a nd S pec trome try . I n R .E . T ay lo r , A . L ong a nd R .S . K ra ( e d s ) R ad iocarbon A f ter F our D ecad e s : A n I n terd i sc ip l inary P e r spec t ive . S p r inge rVe r lag , N ew Yo rk . p p . 1 98 -213 .

S chof ie ld , J .C . 1 978 . T or le s se S uperg roup S t ra t ig raphy : A uck land -N or thwe s t Wa ika to . I n R .P . S ugga te ( Ch ief E d . ) T he G eo logy o f N ew Z ea land , V o lume I . N ew Z ea land G eo log ica l S urvey , D epar tmen t o f S c ien t if i c a nd I ndus t r ia l R e sea rch , We l l ing ton , N ew Z ea land . p p . 2 65 .

P res ton -Thomas , J . 1 994 . S 8 / 171 G rea t B ar r ier I s land : C harcoa l A na lys is . F ie ld S choo l A ss ignmen t 0 3 .340 . D epar tmen to f An thropo logy , U n ive r s i ty o fA uck land . P u l la r , W .A . 1 959 . T he s i gn if i cance o fv o lcan ic a sh b ed s i n a r chaeo logy .J ourna lo ft h eP o lyne s ian S oc ie ty 6 8 (1) :8 11 .

S chof ie ld , J . C . 1 979 . P t S hee t s N 38 , N 39 , N 42 , N 43 Wa iheke . G eo log ica l Map o f N ew Z ea land 1 :63 ,360 . D epa r tmen t o f S c ien t if i c a nd I ndu s t r ia l R esea rch , We l l ing ton , N ew Z ea land .

P u l la r , W .A . 1 959 . A ge o f K aha roa A sh . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 5 ( 1) :17 18 .

S hawcross , F .W . 1 968 . T he Nga ro to S i te . N ew Z ea land A rchaeo log ica lA s soc ia t ion N ew s le t ter 9 (2 ) :53 -7 1 .

R af te r , T .A . , 1 972 . N ew P roceed ing s R ad ioca rbon

J ansen , H .S . , L ocke rb ie , La nd T ro t te r , M .M . Z ea land R ad iocarbon R ef erence S tandard s . o f t he 8 t h I n ter n a t iona l C onf e rence o n D a t ing . p p . 6 25 -675 .

S heppa rd , P . J . , B a rke r , P . , I rw in , G . , J one s , M . , S t evenson , C . , a nd S u t ton , D .G . 1 996 . T he d eve lopmen t a nd a pp l ica t ion o f N ew Z ea land o bs id ian h yd ra t ion d a t ing , 1 996 -1998 . A rchaeo logy i nN ew Z ea land 3 9 (1) : 1 6 -29 .

R a smus sen , K .L . a nd R ahbek , U . 1 993 . "C R e ser vo ir Ef ec t i n G reen land . Manusc r ip t h e ld a t U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra to ry .

S k inne r , D .N .B . 1 978 . T or /e s se S uperg roup S t ra t ig raphy : C oromand e l -W a ika to - K ing C oun t ry . I n R .P . S ugga te ( Ch ief E d .) T he G eo logy o fN ew Z ea land , V o lume I .N ew Z ea land G eo log ica l S u rvey , D epa r tmen t o f S c ien t if ic a nd I ndus t r ia l R esea r ch , We l l ing ton ,N ew Z ea land . p p . 2 67 .

R edve r s -New ton , N .A . , 1 995 . R ad ioca rbon d a t ing h uman b one f r om N amu , T aumako , S o lomon I s lands ; Ac ompa r ison o f t wo m e thods o f b one p r e t rea tmen t . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 3 8 (2 ) :106 - 11 6 .

S k inne r , H .D . , 1 92 1 . C u l tu re a r ea s i nN ew Z ea land . J ourna l o ft h eP o lyne s ian S oc ie ty 3 0 :7 1-78 . S k inne r , H .D . , 1 923 . A rchaeo logy o fC an te rbury . R ecord s o f t h eC an terbury Mu seum 3 : 93 104 .

R edve r s -New ton , N .A . , a nd G .E . C oo te , 1 994 . B one p re t rea tmen ts f o r r ad ioca rbon d a t ing : as t udy i n corpo ra t ing

15

B IBL IOGRAPHY T anaka , N . , Monaghan , M .C . a nd R ye , D .M . 1 986 . C on t r ibu t ion o f me tabo l ic c a rbon t o mo l lusc a nd b arnac le c a rbona te .N a ture 3 20 :520 -523 .

Sm i th , S .P . , 1 921 . Hawa ik i : T he O r ig ina l Home land o ft h e Maor i . C hr is tchurch : Wh i tcombe a nd T ombs . S ou thon , J .R . a nd K a shga r ian , M . 1 994 . R ad ioca rbon A ge s o f P re -Bomb S urf ace O cean Wa te r s . A b s t rac t , 1 5 th I n terna t iona l R ad ioca rbon C onf e rence , p p . C -14 .

T ay lo r , M . 1 995 . AP re l im inary R epo r t o n t he E xcava t ion a t K okohu ia , S ou th Hok ianga . U npub l ished r e po r t h e ld a t U n ive r s i ty o f Wa ika to R ad ioca rbon D a t ing L abo ra tory , H am i l ton .

S p r iggs , M . a nd Ande r son , A . 1 993 . L a te c o lon iza t ion o f E a s t P o lyne s ia .A n t iqu i ty 6 7 :200 -217 .

T ay lo r , R .E . 1 987 . R ad iocarbon D a t ing : An A rchaeo log ica l P e r spec t ive . A cadem ic P ress , I n c . , S an D iego , U SA .

S t evens , G .R . 1 978 . C re taceou s P a laeon to logy - Ma ta S er ie s . I n R .P . S ugga te ( Ch ief E d . ) T he G eo logy o fN ew Z ea land , V o lume 1 . N ew Z ea land G eo log ica l S u rvey , D epa r tmen t o f S c ien t if ic a nd I ndus t r ia l R esea rch , We l l ing ton , N ew Z ea land . p p . 3 62 -366 .

T ev io tda le , D . , 1 932 . T he ma te r ia l c u l ture o f t h e moa h un te r s i n Mu r ih iku . J ourna l o f t h e P o lyne s ian S oc ie ty 4 1 :8 1120 .

S t evenson , C .M . , S heppa rd , P . J . , a nd S u t ton , D .G . 1 996 . Advances i nt h e H ydra t ion D a t ing o fN ew Z ea land Ob s id ian . J ourna lo fA rchaeo log ica lS c ience 2 3 : 2 33 -242 .

T ev io tda te , D . 1 938 . E xcava t ion o f am oa -hun te r s c amp n ea r t h e mou th o ft h e Wa i tak i R ive r . J ou rna l o ft h e P o lynes ian S oc ie ty 4 8 :167 185 .

S tu ive r , M . 1 983 . I n terna t iona l Ag reemen t s a nd t h e U se o f t h eN ew Oxa l ic A c id S tanda rd . R ad ioca rbon 2 5 (2 ) :793-795 .

T homp son , B .N . 1 960 . S hee t 2 B -B arr ie r ( 1 s t e d) G eo log ica l Map o fN ew Z ea land 1 : 250 ,000 . D epa r tmen t o f S c ien t if ic a nd I ndus t r ia l R esea r ch , We l l ing ton , New Z ea land .

S tu ive r , M . a nd B ecke r , B . 1 993 . H igh -P rec is ion D ecada l C a l ib ra t ion o ft h e r ad ioca rbon T ime S ca le , AD 1 950 - 6 000 BC . R ad iocarbon 3 5( 1) : 3 5 -65 . S tu ive r , M . a nd B raz iuna s , T .F . 1 993 . Mode l l ing A tmo spher ic C 14 I nf luences a nd C 14 Age s o f Ma r ine S amp les t o 1 0 ,000 BC . R ad iocarbon 3 5 ( 1) :137 189 .

T hompson , B .N . 1 978 . S t ra t ig raph ic r e la t ions o fm a jor r ock g roups o f N or th land . I n R .P . S ugga te ( Ch ief E d . ) T he G eo logy o f N ew Z ea land , V o lume 1 . N ew Z ea land G eo log ica l S urvey , D epa r tmen t o f S c ien t if ic a nd I n dus t r ia l R e sea rch , We l l ing ton , New Z ea land . p p .4 44 .

S tu ive r , M . , P ea r son , G .W . a nd B raz iuna s , T .F . 1 986 . R ad ioca rbon A ge C a l ib ra t ion o f Ma r ine S amp le s B ack t o 9 000 CAL YR B P . R ad iocarbon 2 8 (2B ) : 9 80 1021 .

T ro t te r , M .M . 1 967a . R ad ioca rbon d a te s f r om No r th O tago . N ew Z ea land A rchaeo log ica l A s soc ia t ion N ew s le t ter 1 0 (4 ) :137 -150 .

S tu ive r , M . a nd P o lach , H .A . 1 977 . D iscu s s ion : R epo r t ing o f CD a ta . R ad iocarbon 1 9 (3) :355 -363 .

T ro t te r , M .M . 1 967b . E xcava t ions a t K a t ik i P o in t , Nor th O tago . R ecord so ft h eC an terbury Mu seum 8 (3 ) : 231-245 .

S tu ive r , M . a nd R e ime r , P . J . 1 993 . E x tended ' 4C D a ta B a se a nd R ev ised CAL IB 3 . 0 ' 4C A ge C a l ib ra t ion P rog ram . R ad iocarbon 3 5 ( 1) :215 -230 .

T ro t ter , M .M . 1 967c . Memo randum t oF o ss L each . H e ld a t t h e D epa r tmen t o f An th ropo logy , U n ive r s i ty o f O tago , D uned in .

S tu ive r , M . , R e ime r , P . J . , B a rd , E . , B eck , J .W . , B ur r , G .S . , H ughen , K .A . , K rome r , B . , McCo rmac , F .G . , v .d .P l ich t , J . , a nd S purk , M . , 1 998a . I NTCAL98 R ad ioca rbon a ge c a l ib ra t ion 2 4 ,000 -0c a l B P . R ad iocarbon 4 0 :104 11083 .

T ro t te r , M .M . 1 968 . On t h e R e l iab i l i ty o f C ha rcoa l f o r R ad ioca rbon D a t ing New Z ea land A rcha eo log ica l S i te s . N ew Z ea land A rchaeo log ica lA ssoc ia t ion N ew s le t ter 1 :86 -88 .

1 4

S tu ive r , M . , R e ime r , P . J . , a nd B raz iuna s , T . F . 1 998b . H igh p rec is ion r a d ioca rbon a ge c a l ib ra t ion f o r t e r re s t r ia l a nd ma r ine s amp le s . R ad iocarbon 4 0 :1127 1151 . S uess , H .E . 1 967 . B r is t lecone -p ine c a l ib ra t ion o f r ad ioca rbon t ime s ca le f r om 4 100 B .C . t o 1 500 B .C . I n R ad ioac t ive Da t ing a nd Me thod s o f L ow -Leve l C oun t ing , I AEA , V ienna , p p . 1 43151 .

T ro t te r , M .M . 1 973 . T akama tua s a lvage , B anks P en insu la . N ew Z ea land A rchaeo log ica l A ssoc ia t ion N ew s le t ter 1 6 (2 ) : 7 6 . T ro t te r , M .M . a nd Ma l thus , R .S . 1 967 . F l uo r ine A na ly s is i n N ew Z ea land A rchaeo logy . N ew Z ea land A rchaeo log ica l A s soc ia t ion N ew s le t ter 1 0 (4 ) :151- 1 57 . T ro t ter , M .M . a nd McCu l loch , B . 1 984 . Moa s , Men a nd M idd en s . I n P .S . Ma r t in a nd R .G . K le in ( eds ) Q ua ternary E x t inc t ions : A P reh i s tor ic R evo lu t ion . T he Un ive r s i ty o f A r izona P re s s , T ucson , A r izona .

S uess , H .E . 1 970 . B r i s t le -cone p i ne c a l ib ra t ion o f r ad ioca rbon t ime s ca le 5 200 B .C . t o t h e p re sen t . I n I . U . O lsson ( ed ) , R ad iocarbon V ar ia t ion a nd A bso lu te C hrono logy . A lmqu is t a nd W ick se l l , S t ockho lm , p p . 3 03 3 12 .

d e V i res , H . 1 958 . V a r ia t ion i nc oncen t r a t ion o fr ad ioca rbon w i th t ime a nd l o ca t ion o n e a r th . I n P roc K on ink l i jke N ed e r land se A kad em ie d er W e ten schrapen , B 6 1 , 9 4 -102 .

S u t ton , D .G . a nd S heppa rd , P . J . 1 994 . D a t ing N ew Z ea land p reh is tory u s ing o bs id ian h yd ra t ion . A rchaeo logy i n N ew Z ea land 3 7 (4 ) : 2 72 -281 .

V oge l , J .C . , F u ls , A . , V isse r , E . a nd B ecke r , B . 1 993 . P r e to r ia C a l ib ra t ion C urve f o r S hor t -L ived S amp les , 1 930 3 350 BC . R ad iocarbon 3 5 ( 1) :73 -85 .

16

B IBL IOGRAPHY Wa rd , G .K . , a nd W i lson , S .R . 1 978 . P rocedures f o r C ompa r ing a nd C omb in ing R ad ioca rbon A ge D e term ina t ions : AC r i t ique .A rchaeome t ry 2 0 ( 1) :19 -31 . Wa t te r s , M . 1 978 . T er t ia ry V o lcan i sm , M iocene : G rea t B a r r ier I s land -C oromand e l -B ay o fP len ty . I nR .P . S ugga te ( Ch ief E d .) T he G eo logy o fN ew Z ea land , V o lume I . N ew Z ea land G eo log ica l S urvey , D epar tmen t o f S c ien t if ic a nd I n dus t r ia l R e sea rch , We l l ing ton ,N ew Z ea land . p p . 6 39 . We idman , C .R . a nd J ones , G .A . 1 993 . AS he l l -De r ived T ime H is tory o fB omb 1 4C o n G eo rge s B ank a nd i t s L ab rado r S ea I mp l ica t ions . J ourna l o fG eophy s ica l R e search , V o l . 9 8 , n o . C 8 :14 ,477 -14 ,588 . We ine r , J . S . , 1 955 . T he P i l tdown F o rge ry . O xf o rd U n ive r s i ty P ress , L ondon . We is le r , M . 1 989 . C hronome t r ic D a t ing a nd L a te H o locene P r eh is to ry i n t h e H awa i ian I s land s : A C r i t ica l R ev iew o f R ad ioca rbon D a tes f r om Mo loka ' i I s land . R ad iocarbon 3 1(2 ) :121-145 . Whee le r , M . 1 954 . A rchaeo log y f rom t h e E a r th . P engu in B ook s , Wyman & S ons L td , L ondon . Whee le r , M . 1 955 . S t i l l D igg ing : A rchaeo logy . P an B ooks L td , L ondon .

Ad ven ture s

i n

W ind le , B .C .A . , 1 904 . R ema in s o ft h e P reh i s tor ic A ge i n E ng land . Me thuen & C o . , L ondon . W i l l is , E .H . , T aube r H . a nd Munn ich K .O . 1 960 . V a r ia t ions i n a tmosphe r ic r ad ioca rbon c oncen t ra t ion o ve r p a s t 1 300 y ea r s . Amer ican J ourna l o f S c ience , R ad iocarbon S upp lemen t2 : 1-4 . W i lson , S .R . , a nd Wa rd , G .K . 1 981 . E va lua t ion a nd C lus te r ing o f R ad ioca rbon A ge D e te rm ina t ions : P rocedu re s a nd P a rad igms .A rchaeome t ry 2 3 ( 1 ) :19 -39 .

17

B IBL IOGRAPHY

18

APPENDIX 1

R ad iocarbon d a t ing l abora tor ie s c urren t ly u nder tak ing AR r e search L abora tory

Me thod

R eg ion AR b e ing d e term ined f o r

I s o tope a nd A rcheome t ry L abo ra to ry , U n ive r s i ty o f C a l if o rn ia , U .S .

K nown a ge s he l ls

C a l if o rn ia s e a coa s ta nd l a ke s

I GNS , We l l ing ton ,N .Z .

K nown a ge s he l ls

S ou the rn N o r th I s land

C en t re d eD a ta t ion p a rl e R ad ioCa rbone , U n ive r s i te C laude B e rna rd L yon I ,F rance

K nown a ge s he l ls?

Med i ter ranean

D epar tmen to fG eo sc ience s , U n ive r s i ty o fA r izona , U .S .

K nown a ge s he l ls

No r thern G u lf o fC a l if or n ia

R ad ioca rbon D a t ing L abo ra to ry , T he Q ueen 's U n ive r s i ty , B e lf a s t , I r e land

P r eh is to r ic b one /ma r ine s he l l p a i r s

I r e land

R ad ioca rbon D a t ing L abo ra to ry , U n ive r s i ty o f Wa ika to , H am i l ton , NZ

P r eh i s to r ic c ha rcoa l /ma r ine s h e l l p a i r s

N o r th a nd S ou th I s land

I n s t i tu te o fP hys ics a nd A s t ronomy , U n ive r s i ty o f A a rhus , D enma rk ( AMS )

K nown a ge s he l ls

D an i sh c oa s t l ine a nd f i o rd s

C en t re f o rA cce le ra to r Ma s s S pec t rome t ry , L aw rence L ivermo re N a t iona l L abo ra to ry , C a l if or n ia ,U .S .

K nown a ge s he l ls ;

C a l ifo rn ia c oa s t , e a s t c oa s to f U n i ted S t a te s , Med i ter ranean , c oa s t s o fI n d ian a nd P ac if ic o ceans

P r eh is to r ic c ha rcoa l /ma r ine s h e l l p a i r s

Wood -she l l p a ir s f r om n a tu ra l b each d epo s i t s ; P r eh i s to r ic w ood / she l l p a i r s ; V a rved s ed imen t s /pe lag ic g a s t ropod p a i r s ; Ma r ine / te r re s t r ia l p a i r s f r om s ame a r chaeo log ica l a r tef ac t s

I s oT ra ce L abo ra tory , U n ive r s i ty o fT o ron to ,O n ta r io ,C anada ( A MS )

T er re s t r ia l /ma r ine p a i r s ; C ha rcoa led f ood /ma r ine f u r r ema ins p a i r s f r om " Ba sque " c oppe rk e t t les ( a r chaeo log ica l a r tef ac t ) ; G uano a nd f ood r ema in s / te r re s t r ia lo rgan ics p a i r s

19

No r th Ame r ican e a s ter ns e aboa rd ; A n ta rc t ica

APPENDIX 2 R ad iocarbon a ge s m ea sured i nt h i s d i s ser ta t ion Wk #

L oca t ion

S amp le T ype

L ibby BP

3 463

Ao tea ,A r ea A ( S8 / 17 1)

C ha r coa l

1 98 ± 4 0

26 .0

3 464

Ao tea ,A rea A ( S8 / 17 1)

P aph i e ss ub t r iangu la tum

7 20 ± 6 0

1 . 8

3 465

A o tea , A r ea A ( S8 / 17 1)

P aph ie sa u s tra l i s

6 40 ± 3 0

1 . 9

3 466 1

Ao tea ,A r ea A ( S8 / 17 1)

A u s t rovenu ss t u tchbu ty i

5 10 ± 4 0

0 . 3

3 466 -2

Ao tea ,A r ea A ( S8 / 17 1)

A u s trovenu ss t u tchbu ty i

5 70 ± 4 0

1 . 3

3 467

Ao tea , A r ea B ( S8 / 17 1)

C ha r coa l

2 20 ± 4 0

2 5 .7

3 468

Ao tea ,A r ea C ( S8 / 16 )

C ha rcoa l

2 20 ± 4 0

26 .7

3 469

Ao tea , A rea C ( S8 / 16 )

A us t rovenu ss t u tchbu ty i

8 20 ± 4 0

0 . 8

3 470

A o tea ,A r ea C ( S8 / 16 )

P aph i es a u s t ra l i s

7 30 ± 4 0

1 . 4

3 47 1

A o tea ,A rea C ( S8 / 16 )

P aph ie ss ub t r iangu la tum

7 30 ± 5 0

3 . 4

3 533

L iga rB ay , S i te N25 /26

C ha r coa l

3 90 ± 4 0

26 .3

3 534

L iga rB ay , S i te N 25 /26

P aph ie ss ub t r iangu la tum

7 40 ± 4 0

1 . 2

3 535

L iga rB ay , S i te N25 /26

P aph ie sa u s t ra l i s

7 60 ± 4 0

1 . 6

3 536

L iga rB ay , S i te N 25 /26

A u s trovenu ss t u tchbu ty i

7 50 ± 4 0

0 . 1

3 537

L iga rB ay , S i te N 25 /26

L une l la s maragda

7 60 ± 4 0

1 . 4

3 538

L iga rB ay , S i te N 25 /26

C om ine l la a d sper sa

7 00 ± 4 0

0 . 8

3 539

L iga rB ay , S i te N 25 /95 , M idden 1

C ha r coa l

4 40 ± 4 0

27 .6

3 540

L iga rB ay , S i te N 25 /95 ,M idden 1

P aph i es s ub t r iangu la tum

8 80 ± 4 0

1 . 2

3 54 1

L iga rB ay , S i te N 25 /95 ,M idden I

P aph i es a us t ra l i s

8 20 ± 4 0

1 . 4

3 542

L iga rB ay , S i te N25 /95 , M idden 1

A u s trovenu ss t u tchbury i

8 40 ± 4 0

0 . 9

3 543

L iga rB ay , S i te N25 /95 ,M idden 1

L une l la s maragda

8 70 ± 4 0

1 . 6

3 544

L iga rB ay , S i te N25 /95 ,M idden 2

C ha r coa l

4 70 ± 4 0

26 .5

1 2 1

A ge

8I 3C

APPENDIX 2

Wk #

L oca t ion

S amp le T ype

L ibby BP

3 545

L iga r B ay , S i te N 25 /95 , M idden 2

P aph ies s ub tr iangu la tum

7 90 ± 4 0

1 . 4

3 546

L iga rB ay , S i te N25 /95 , M idden 2

P aph ies a u s tra l i s

9 20 ± 4 0

1 . 6

3 547

L iga rB ay , S i te N25 /95 , M idden 2

A us trovenus s t u tchbury i

8 40 ±4 0

0 . 5

3 548

L iga rB ay , S i te N25 /95 , M idden 2

L une l la s maragda

8 90 ±4 0

1 . 2

3 549

L iga rB ay , S i te N25 /95 , M idden 2

My t i lus e du l i sa o teanus

8 80 ±4 0

2 . 0

3 578

P onu i I s . N43 / 1

P aph ies a us tra l i s

8 40 ±4 0

1 . 3

3 579

P onu i I s . N43 / 1

A us trovenus s t u tchbur y i

8 50 ±4 0

1 . 0

3 580

P onu i I s . N43 / 1

V enerup i sl a rg i l l ier t i

8 60 ± 4 0

0 . 3

3 58 1

P onu i I s . N43 / 1

P erna c ana l icu lus

8 20 ±4 0

0 . 6

3 582

P onu i I s . , N43 /333

C ha rcoa l

4 00 ± 4 0

2 5 .7

3 583

P onu i I s . , N43 /333

P aph ies a us tra l i s

5 90 ± 5 0

1 . 2

3 584

P onu i I s . , N43 /333

A us trovenus s t u tchbury i

5 20 ±4 0

0 . 8

3 585

P onu i I s . , N43 /333

C ra sso s tr ea g lomera ta

5 20 ±4 0

0 . 8

3 586

P onu i I s . N43 /333

C ha rcoa l

4 10 ± 4 0

26 .7

3 587

P onu i I s . N43 /333

C ha rcoa l

4 30 ± 4 0

26 .0

3 588

P onu i I s . N43 /333

P aph ies a us t ra l i s

8 90 ± 4 0

0 . 8

3 589

P onu i I s . N43 /333

A us trovenus s t u tchbur y i

9 30 ±4 0

0 . 7

3 590

P onu i I s . S i te 1 4

C ha rcoa l

6 20 ± 4 0

26 .1

3 59 1

P onu i I s . S i te 1 4

P aph ies a us t ra l i s

9 20 ± 4 5

1 . 0

3 592

P onu i I s . S i te 1 4

A us trovenu ss t u tchbu ry i

9 40 ±4 0

0 . 9

3 593

P onu i I s . S i te 1 4

P erna c ana l icu lus

9 10 ± 4 0

1 . 5

3 594

P onu i I s . S i te 1 4

C ras so s t rea g lomera ta

9 00 ± 4 0

I . /

3 596

P onu i I s . S i te 2 7

C ha rcoa l

4 70 ±4 0

26 .1

3 597

P onu i I s . S i te 2 7

P aph ie sa us tra l i s

7 40 ± 4 0

1 . 6

3 598

P onu i I s . S i te 2 7

A us trovenus s t u tchbury i

8 20 ± 4 0

0 . 5

3 599

P onu i I s . S i te 9 5

C ha rcoa l

1 87 ± 3 0

25 .8

3 600

P onu i I s . S i te 9 5

A us trovenus s t u tchbu ry i

7 70 ± 4 0

1 . 3

3 60 1

P onu i I s . S i te 9 5

C ha rcoa l

6 00 ±4 5

25 .0

3 602 1

P onu i I s . S i te 9 5

A us trovenus s t u tchbu ry i

1 560 ± 4 0

0 . 8

3 602 -2

P onu i I s . S i te 9 5

A us trovenus s t u tchbury i

1 480 ± 5 0

0 . 8

3 678

Ao tea , A rea B ( S8 / 171)

P aph ies s ub t r iangu la tum

6 60 ±4 0

1 . 8

3 679

Ao tea , A rea B ( S8 / 171)

P aph ies a us t ra l i s

6 80 ±4 0

1 . 8

3 680

Ao tea , A rea B ( S8 / 17 1)

A us trovenus s t u tchbury i

6 30 ± 4 0

1 . 4

3 695

K okohu ia

C ha rcoa l

3 30 ± 4 5

25 .7

3 696

K okohu ia

P aph ie sa us tra l i s

7 10 ±4 0

1 . 14

3 697

K okohu ia

A us trovenus s t u tchbu ry i

7 70 ± 4 0

0 .1

1 22

Age

81 3c

APPENDIX 2

Wk #

L oca t ion

S amp le T ype

L ibby B P

3 698

K okohu ia

V enerup i s l a rg i lher t i

6 80 ± 4 0

0 . 4

3 699

K okohu ia

L une l la s maragda

7 60 ±4 0

1 . 5

3 70 1

K okohu ia

P erna c ana l icu lus

8 00 ± 4 0

1 . 7

3 703

K okohu ia

C ha rcoa l

4 10 ± 4 0

26 .2

3 704

K okohu ia

P aph ies a us tra l i s

7 10 ±4 0

1 . 0

3 705

K okohu ia

A u s trovenus s t u tchbu ty i

7 50 ±4 0

0 . 1

3 706

K okohu ia

V enerup i sl a rg i l l ier t i

7 20 ± 4 0

0 . 5

3 707

K okohu ia

L une l la s maragda

7 50 ±4 0

1 . 4

3 709

K okohu ia

P erna c ana l icu lus

7 40 ± 4 0

1 . 3

3 711

K okohu ia

C ha rcoa l

3 70 ±4 0

26 .2

3 7 12

K okohu ia

P aph ies a us tra l i s

8 10 ± 4 0

1 . 0

3 7 13

K okohu ia

A us t rovenus s t u tchbu ty i

7 50 ± 4 0

0 . 7

3 7 15

K okohu ia

L une l la s maragda

7 70 ± 4 0

1 . 5

3 7 16

K okohu ia

C om ine l la v i rga ta

7 50 ± 4 0

0 . 2

3 7 18

K okohu ia

C ha rcoa l

3 80 ± 4 0

25 .7

3 7 19

K okohu ia

C ha rcoa l

4 40 ±4 0

25 .1

3 720

K okohu ia

C ha rcoa l

4 90 ±4 0

26 .0

3 72 1

K okohu ia

C ha rcoa l

5 10 ± 4 5

25 .7

3 722

K okohu ia

P aph ies a us tra l i s

7 90 ± 4 0

0 . 6

3 723

K okohu ia

A us trovenus s t u tchbu ty i

8 10 ± 4 0

0 .5

3 724

K okohu ia

L une l la s maragda

8 20 ± 4 0

1 . 0

3 726

K okohu ia

C om ine l la v i rga ta

8 40 ±4 5

0 . 8

3 727

K okohu ia

P erna c ana l icu lus

8 20 ±4 5

1 . 5

4 028

S awp i t P o in t ( N26 /2 14 )

C ha rcoa l

3 50 ±4 0

26 .8

4 029

S awp i tP o in t ( N26 /2 14 )

C ha rcoa l

4 10 ±4 0

26 .7

4 030

S awp i t P o in t ( N26 /2 14 )

A u s trovenus s t u tchbu ty i

7 90 ± 4 0

1 . 2

4 031

S awp i tP o in t ( N26 /2 14 )

L une l la s maragda

8 00 ± 4 0

2 . 1

4 032

S awp i t P o in t ( N26 /2 14 )

A us trovenus s t u tchbu ty i

1 870 ± 5 0

0 . 9

4 033

S awp i tP o in t ( N26 /2 14 )

P aph ies a us tra l i s

8 30 ±4 0

1 . 6

4 482

K okohu ia

C ha rcoa l

4 50 ±4 0

25 .5

4 483

K okohu ia

C ha rcoa l

4 90 ± 4 0

25 .7

4 484

K okohu ia

C ha rcoa l

3 80 ±4 0

26 .1

4 485

K okohu ia

C ha rcoa l

3 40 ±4 0

25 .7

4 486

K okohu ia

C ha rcoa l

4 10 ± 4 0

26 .0

4 487

K okohu ia

C ha rcoa l

3 80 ± 4 0

25 .8

4 540

K okohu ia

C ha rcoa l

3 60 ± 4 0

25 .5

4 54 1

K okohu ia

C ha rcoa l

3 50 ±4 0

25 .6

1 23

A ge

8D C

APPEND IX 2

Wk #

L oca t ion

S amp le T ype

L ibby B P

4 542

K okohu ia

C ha rcoa l

4 30 ± 4 0

2 5 .2

4 543

K okohu ia

C ha rcoa l

4 80 ±4 0

2 5 .2

4 544

Kokohu ia

C ha rcoa l

4 10 ±4 0

2 5 .2

1 24

A ge

89 C