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In situ oxygen isotope analysis of faunal material using
a secondary ion micro-probe:
a new tool for palaeoecology and archaeology.
Maxime Aubert1, Ian Williams1,
Rainer Grün1, Tegan
Kelly1, Ian Moffat1 and Marie-Hélène Moncel2
1 Research School of Earth Sciences, Australian National University, Canberra,
ACT 0200, Australia
2 Département de Préhistoire Muséum National d'Histoire Naturelle 1 Rue
René Panhard, 75013 Paris, France
Figure
1. Oxygen isotopic compositions of a fossil otolith from the Australian
Willandra Lakes World Heritage area showing a general trend to heavier
oxygen isotopes, indicating an enrichment in heavy isotopes due to
increased evaporation
We have applied in situ oxygen isotope analysis on Neanderthal and herbivore
teeth from the archaeological site of Payre as well as fossil fish otoliths
from Australia. The high resolution of the oxygen isotope analysis allows
weekly to bi-weekly resolution of human teeth. We observed large variations
in the oxygen isotopic composition in the enamel of herbivore teeth,
which were on a scale expected from seasonal variations. The range of
isotopic variations in Neanderthal tooth enamel was much smaller, perhaps
reflecting a more restricted range of diet and/or more uniform sources
of drinking water when the teeth were growing. The application of fish
otoliths from the Australian Willandra Lakes World Heritage area showed
significant isotopic variations indicating seasonal variations but also
a general trend towards heavier oxygen isotopes, which may be due to
an enrichment in heavy isotopes as a result of increased evaporation
(Fig 1). We will pursue with the oxygen isotope research on fish otoliths
as these seem ideal archives of past environmental conditions.