Oxygen and carbon isotope compositions of well-preserved mammoth teeth
from the Middle Wurmian (40-70 ka) peat layer of Niederweningen, the
most important mammoth site in Switzerland, were analysed to reconstruct
Late Pleistocene palaeoclimatic and palaeoenvironmental conditions.
Drinking water (delta(18)O values of approximately -12.3 +/- 0.9 parts
per thousand were calculated front oxygen isotope compositions of
mammoth tooth enamel apatite using a species-specific calibration for
modern elephants. These delta(18)O(H2O) values reflect the mean oxygen
isotope composition of the palaeo-precipitation and are similar to those
directly measured for fate Pleistocene groundwater from aquifers in
northern Switzerland and southern Germany. Using a present-day
delta(18)O(H2)o-precipitation-air temperature relation for Switzerland,
a mean annual air temperature (MAT) of around 4.3 +/- 2.1 degrees C can
be calculated for the Middle Wurmian at this site. This MAT is in good
agreement with palaeotemperature estimates on the basis of Middle
Wurmian groundwater recharge temperatures and beetle assemblages. Hence,
the climatic conditions in this region were around 4 degrees C cooler
during the Middle Wurmian interstadial phase, around 45-50ka BP, than
they are today.
During this period the mammoths from Niederweningen lived in an open
tundra-like, C(3) plant-dominated environment as indicated by enamel
(delta(13)C values of -11.5 +/- 0.3 parts per thousand and pollen and
macroplant fossils found in the embedding peat. The low variability of
enamel delta(13)C and delta(18)O values from different mammoth teeth
reflects similar environmental conditions and supports a relatively
small time frame for the fossil assemblage. (C) 2006 Elsevier Ltd and
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