Cuddie Springs

[Richard Gillespie]

Some comments on the Judy Field/Richard Fullagar view from Cuddie Springs:

>1. a complete pollen record showing trends which are consistent with other
>pollen records for the same period (see Dodson et al., 1993; Furby, 1995;
>Field et al., in press)

Maybe it's time for data in the unpublished Furby (1995) thesis to be made
public.

>3. a set of dates for the site (now more than 15 different independent
>samples using 14C, TL and OSL) are consistent across the stratigraphy.  The
>site is securely dated.

The charcoal and sand are certainly well dated, but not necessarily the
bones, stones or pollen. However, the distribution of charcoal ages is not
Gaussian (as it is eg. at Ngarrabullgan) but randomly placed throughout
70cm of sediments in archaeological units 1 & 2. Full publication of the
collaborative OSL dating program results has not yet happened. None of the
megafaunal remains have been directly dated.

>7. The whole human/megafauna deposit is sealed between two old land
>surfaces; the upper is a 'deflation pavement' formed during a period of
>peak aridity around the LGM and the lower is a concreted beach lag deposit.

There are also large slabs of deposit missing at those two old land
surfaces, with the 1m of deposits above the 'deflation pavement' containing
both modern cow bones and extinct megafauna. There seem to be no
articulated megafaunal remains either below or above the concreted beach
lag deposit.

>If we are to continue the debate on megafaunal extinctions, let us base our
>arguments on rigorous data and consideration of all the facts.

Some facts not widely discussed include:
(1) Of 10 bone samples excavated from Cuddie Springs (analysed by me), only
the modern cow bone contained amino acids. Collagen in both extant &
extinct marsupial bones has been replaced by minerals, similar to bones
found at Lancefield Swamp and many other megafaunal sites.
(2) Teeth analysed by Simon Clarke (unpublished honours thesis, UoW) show
widely scattered D/L values for the very scarce amino acids present, even
less suitable for AAR dating than those from Lancefield. You can calculate
any age you like between Holocene and 70ka from the Cuddie Springs D/L data.
(3) The sediments contain, in addition to the dated macro charcoal,
well-preserved pollen & macro plant debris as well as identifiable organic
residues on stone tools. This is in complete contrast to the very
poorly-preserved skeletal remains, a disharmonious assemblage in my view.
(4) For dating the megafauna, radiocarbon will not work because there is no
carbon in the bones, and because of the altered mineralogy other methods
are also unlikely to yield reliable dates. It might be worthwhile to
directly date some of the pollen and other plant bits present, or fragments
of unionid shell also found. This analytical and observational data might
also have been published.

Raising Lancefield here does not imply that the depositional environments
were similar, but some consideration of others sites with disharmonious
assemblages of archaeology and megafauna seems in order. At Lancefield
there were post-bomb plant roots below the bone bed, regretably my attempts
to get dates on similar material (and the pollen-sized burnt and unburnt
bits) at Cuddie were not approved. There is no reasonable chemical
explanation for some organic bits such as proteins to be well preserved
with other proteins badly degraded or absent in the same stratigraphic
unit, unless they are different in age and/or exposure to diagenetic
processes.

Since the Cuddie Springs sand contains mixed age components (Roberts et
al's point) it is likely that the larger bits (bones and stones) are also
of mixed age. There are no hearths recorded in the excavation literature,
perhaps not too surprising for an ephemeral lake site, so the charcoal must
have come from somewhere else (as did the stones). It is then no major leap
to infer that the bones are also reworked, possibly from deeper in the site
by natural erosion/redeposition processes or modern palaeontological
excavations and well digging.

Any interaction between people and megafauna at Cuddie Springs is still a
subjective interpretation based on proximity of bones and stones, and one
possibly burnt bone (though why that particular bone is thought to be burnt
has not been adequately discussed). To convince the sceptical, much more
needs to be published on the geomorphology of site formation, low relief
landscape does not necessarily mean a low energy depositional environment
for all time. Bruno David points out in his forthcoming book that seed
grinding tools are claimed to be 35ka at Cuddie Springs but appear to be
Holocene everywhere else. Another aspect of disharmonious assemblage?

The charcoal and sand so far dated from archaeological units 1 & 2 at
Cuddie Springs are in the same time period  (35+/-3 ka) as numerous other
Australian archaeological sites, equivalent to eg. Arumpo Unit times in the
Willandra and well before LGM aridity dried out those lakes. None of the
other sites contain extinct megafauna in direct association with artefacts
of human occupation. If Miller et al (1999) and Roberts et al (2001) are
correct, the explanation is simply that Genyornis and several genera of
large marsupials were all extinct by ca. 45 ka. The scientific evidence is
now very good that people were living at eg. Carpenter's Gap, Riwi, Devil's
Lair and the Willandra ca.44ka, but no compelling evidence that either
people or megafauna were living at Cuddie Springs then. It would still of
course be nice to know how the charcoal, bones and stones came to be
together.

cheers, richard
(Please Note: hitting the automatic Reply button will cause responding
email to come back to me rather than to the list, which I regret but my ISP
can't seem to fix)

=========================================================

Dr Richard Gillespie
Radiocarbon Dating Consultant
Dizzy Heights, Ripps Road
Stokers Siding NSW 2484
Australia
Phone: (02) 6677 9500		Email: dizzy at better.net.au