Australian Archaeology

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Archived at Flinders University: dspace.flinders.edu.au

Full Citation Details:

Bowdler, S. 1975. Further Radiocarbon Dates from Cave Bay Cave,

Hunter Island, North-West Tasmania. 'Australian Archaeology',

no.3, 24-26.

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FLJRTHER RADIOCARBON DATES FROM CAVE BAY CAVE, HUNTER ISLAM), NORTH-WEST TASMANIA

Man's presence i n Tasmania during t h e P l e i s t o c e n e was r e c e n t l y demonstrated by a radiocarbon d a t e of 18,550

+

^{600 BP}

(ANU-1361) from Cave Bay Cave, Hunter I s l a n d (Bowdler 1974a, b ) . Further excavation was c a r r i e d o u t a t t h i s s i t e during January and February of t h i s year, and more radiocarbon d a t e s a r e t o hand. The archaeological sequence suggested b e f o r e h a s been considerably c l a r i f i e d , and the new d a t e s extend t h e a n t i q u i t y of man i n t h e region by some 4,000 y e a r s .

The s i t e is l a r g e and, of a s e r i e s of t r e n c h e s , t h a t located n e a r e s t t h e c e n t r e of t h e cave (Trench V) most c l e a r l y e x h i b i t s t h e s a l i e n t f e a t u r e s of i t s h i s t o r y . This c u t t i n g w a s 2 m X 2 m i n a r e a , and was excavated t o a depth of a l i t t l e over 2 m. P l e i s t o c e n e l a y e r s were again recognised by non-island fauna1 remains, c h a r a c t e r i s i n g t h e 'Hunter H i l l on Bass P l a i n ' period of lowered s e a l e v e l (Bowdler 1974a:7-8). The topmost P l e i s t o c e n e l a y e r s o defined was encountered approximately 65 cms below t h e s u r f a c e i n Trench V. Between 145 and 185 cms were a s e r i e s of well-defined hearthy l a y e r s , r i c h i n macropod bones, q u a r t z f l a k e s and charcoal. I n no o t h e r trench w a s such i n t e n s i v e evidence of P l e i s t o c e n e occupation discovered. The lowest of t h e s e l a y e r s (c.175-185 cms) was s t r a t i g r a p h i c a l l y t h e o l d e s t evidence found f o r man's presence i n the s i t e . Associated c h a r c o a l has yielded a d a t e of 22,750

+

420 BP ( W - 1 4 9 8 ) . A p r e l i m i n a r y d a t e of about 20,800 BP has been received f o r t h e uppermost hearthy

l a y e r i n t h i s complex (c. 145-150 cms)

.

Above t h i s (120 cms

-

145 cms) t h e r e i s sporadic evidence of human occupation, a s s o c i a t e d with what appears t o be a period of p a r t i c u l a r l y heavy r o o f - f a l l . Between 65 and 120 cms t h e r e is v i r t u a l l y no s i g n of t h e presence of man, with

t h e exception of a small, well-defined h e a r t h 85 cms below t h e s u r f a c e . A preliminary d a t e f o r t h i s h e a r t h s u g g e s t s i t is about 15,500 y e a r s old.

Various a s p e c t s of t h e P l e i s t o c e n e h i s t o r y of t h e s i t e are c u r r e n t l y being explored, but t h e following c l i m a t i c c o r r e l a t i o n s may be t e n t a t i v e l y i n f e r r e d . It appears t h a t t h e most i n t e n s i v e u s e of t h e s i t e by P l e i s t o c e n e man spanned about 2000 y e a r s , j u s t b e f o r e the l a s t p l e n i g l a c i a l . There is no reason why t h i s should r e p r e s e n t man's f i r s t p e n e t r a t i o n of t h e Tasmanian peninsula; Tzsmania may w e l l have been i n i t i a l l y colonised under a c l i m a t i c r6gime less s e v e r e than has been previously suggested (Jones 1968:200). The subsequent period of i n t e n s e r o o f - f a l l and sporadic u s e of t h e s i t e may coincide with the l a s t g l a c i a l maximum of c.18,000 BP The d a t e p r e v i o u s l y r e p o r t e d

(from Trench 11) may be r e c a l l e d , a s s o c i a t e d a s i t w a s with a s i n g l e bone a r t e f a c t and two p i e c e s of f l a k e d q u a r t z (Bowdler l974b). The i s o l a t e d h e a r t h dated t o about 15,500 BP r e p r e s e n t s a p e r i o d w e l l

before t h e r e t r e a t of t h e Tasmanian g l a c i e r s (Macphail C P e t e r s o n 1975).

Hence i t appears t h a t Cave Bay Cave was l a r g e l y unoccupied during a period of p o s s i b l e c l i m a t i c amelioration. This i s n o t n e c e s s a r i l y t o imply t h a t the cave was a cosy r e t r e a t from h a r s h weather. One p o s s i b l e l i n e of enquiry might look t o v e g e t a t i o n a l changes, p a r t i c u l a r l y i f t h e

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lower o c c u p a t i o n a l l e v e l s a r e i n t e r p r e t e d a s r e p r e s e n t i n g a h u n t i n g camp r a t h e r t h a n a b a s e camp. I t i s hoped t h a t a n a l y s i s of p o l l e n samples b e i n g u n d e r t a k e n by D r Geoffrey Hope w i l l shed f u r t h e r l i g h t h e r e .

The t o p 65 c m of d e p o s i t r e f l e c t f u r t h e r e p i s o d e s of use and d i s u s e of t h e s i t e by man, b u t perhaps more e a s i l y i n t e r p r e t e d . Between 50 and 65 crns below t h e s u r f a c e i s a l a y e r of r i c h s h e l l midden, d i s c r e t e l y s t r a t i f i e d above t h e topmost c u l t u r a l l y s t e r i l e P l e i s t o c e n e l a y e r . Charcoal from t h e bottom 5 cms of t h i s midden h a s b e e n d a t e d t o 7180

+

90 BP (ANU-1552). The orange-brown l a y e r of Trench I which c o n t a i n e d f o u r bone a r t e f a c t s may b e c o r r e l a t e d w i t h t h i s midden l a y e r (Bowdler l974a: 6 ) . A p r e l i m i n a r y d a t e of

t h e o r d e r o f 4000 BP h a s been o b t a i n e d from a small h e a r t h a couple of c e n t i m e t r e s above t h e t o p of t h e midden p r o p e r . Above t h i s a r e a t l e a s t 25 crns of c u l t u r a l l y s t e r i l e sandy d e p o s i t ; and above t h i s a g a i n a b o u t 25 crns o f h e a r t h s and l e n s e s of s h e l l midden.

The d a t i n g of t h e bottom of t h e midden c o i n c i d e s w e l l w i t h r e c e n t geomorphological e v i d e n c e f o r t h e s e a r e a c h i n g i t s p r e s e n t l e v e l i n A u s t r a l i a (Thom & Chappell 1975: 91). Comparison may a l s o b e made w i t h t h e l o w e s t l e v e l s of Rocky Cape South (Jones 1968:200)

.

A t t h i s p o i n t Cave Bay Cave became a c o a s t a l s i t e i n terms of both i t s e n v i r o n m e n t a l s e t t i n g and of human usage. I s u g g e s t t h a t a t t h i s t i m e H u n t e r I s l a n d had y e t t o come i n t o e x i s t e n c e ; r a t h e r we may t h i n k of Hunter P e n i n s u l a . J e n n i n g s (1959:63) h a s suggested t h a t

t h e deep c h a n n e l s around Hunter I s l a n d could b e t h e r e s u l t o f post- g l a c i a l t i d a l s c o u r i n g . I f s o , t h e r e may have been an i n t e r v a l between t h e s e a a p p r o x i m a t i n g i t s p r e s e n t l e v e l and t h e f i n a l c r e a t i o n of Hunter I s l a n d i s l a n d . P e r h a p s , a s Lampert h a s suggested f o r Kangaroo I s l a n d (1972:223), t h e r e was a g r a d u a l e r o s i o n of t h e l a n d l i n k and a g r a d u a l r e t r e a t by man t o t h e Tasmanian main, f i n a l l y abandoning t h e i n c i p i e n t i s l a n d s h o r t l y a f t e r 4000 BP. Abandoning i t , t h a t i s , f o r a c o u p l e of thousand y e a r s .

I f t h e s t e r i l e l a y e r (which was found i n a l l t r e n c h e s ) r e p r e s e n t s a p e r i o d o f non-occupation, t h e n t h e top 30 crns o r s o of h e a r t h s and midden r e p r e s e n t t h e maritime d i s c o v e r y of Hunter IsZand,

and i t s s u b s e q u e n t , p r o b a b l y s e a s o n a l , e x p l o i t a t i o n , as I have s u g g e s t e d b e f o r e (Bowdler 1974a:B). A carbon d a t e of 2580

+

^{70 BP}

(ANU-1362) from a n e q u i v a l e n t l a y e r i n Trench I1 s u g g e s t s a d a t e f o r t h i s triumph o f Tasmanian n a v i g a t i o n ; c o n f i r m a t i o n from Trench V i s awaited.

Acknowledgements

T h i s p r o j e c t i s e n t i r e l y supported by t h e A u s t r a l i a n N a t i o n a l U n i v e r s i t y ; r a d i o c a r b o n d a t e s were processed by t h e Radiocarbon

L a b o r a t o r y of t h a t i n s t i t u t i o n , and I t h a n k John Head and Henry Polach.

Fieldwork on Hunter I s l a n d was made p o s s i b l e by t h e kindness o f P a t Maguire and f a m i l y .

Sandra Bowdler,

Department of P r e h i s t o r y

,

Research School of P a c i f i c S t u d i e s ,

A.N.U. CANBERRA

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