HR: 08:15h
AN: PP41D-02    [Abstracts]
TI: Paleo-aridity index for terrestrial deposits
AU: * Cerling, T E
EM: tcerling@comcast.net
AF: University of Utah, 1460 East 135 South, Salt Lake City, UT 84112 United States
AU: Levin, N E
EM: nlevin@mines.utah.edu
AF: University of Utah, 1460 East 135 South, Salt Lake City, UT 84112 United States
AU: Passey, B H
EM: bpassey@mines.utah.edu
AF: University of Utah, 1460 East 135 South, Salt Lake City, UT 84112 United States
AU: Harris, J M
EM: jharris@usc.edu
AF: George C. Page Museum, 5801 Wilshire Blvd, Los Angeles, CA 90036 United States
AU: Ehleringer, J R
EM: ehleringer@biology.utah.edu
AF: University of Utah, 1460 East 135 South, Salt Lake City, UT 84112 United States
AB: We present a paleo-aridity index for terrestrial deposits based on comparing 18-O in tooth enamel. Oxygen-18 is enriched in the residual fluid during evaporation, for example in lakes or in leaves. We characterize taxa that are sensitive to evaporation (ES) and compare them to others that are not sensitive to evaporation (EI). The 18-O concentration in body water is preserved in tooth enamel, and differences between ES and EI taxa is well correlatin with water deficit, where water deficity is MAP-PET (mean annul precipitation minus potential evapotranspiration). During a survey of stable isotope values from ca. 1500 mammals in East Africa, where the signal is less complicated than higher latitudes, we find that we can estimate water deficit to ñ 400 mm/a.
DE: 1041 Stable isotope geochemistry (0454, 4870)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005