500,000-year stable carbon isotopic record from devils hole, nevada.
The record of carbon-13 (delta(13)C) variations in DH-11 vein calcite core from Devils Hole, Nevada, shows four prominent minima near glacial terminations (glacial-interglacial transitions) V to II. The delta(13)C time series is inversely correlated with the DH-11 oxygen isotope ratio time series and leads it by as much as 7000 years. The delta(13)C variations likely record fluctuations in the delta(13)C of dissolved inorganic carbon of water recharging the aquifer. How such variations are transported 80 kilometers to Devils Hole without obliteration by water-rock reaction remains an enigma. The record may reflect (i) global variations in the delta(13)C of atmospheric CO(2) and, hence, the delta(13)C of continental biomass or (ii) variations in extent and density of vegetation in the southern Great Basin. In the latter case, delta(13)C minima at 414, 334, 246, and 133 thousand years ago mark times of maximum vegetation.
Coplen
T B
TB
Winograd
I J
IJ
Landwehr
J M
JM
Riggs
A C
AC