2004 Denver Annual Meeting (November 7–10, 2004)
Paper No. 29-8
Presentation Time: 3:30 PM-3:45 PM

87SR/86SR AND SR/CA IN SPELEOTHEMS FOR PALEOCLIMATE RECONSTRUCTION

LI, Hongchun, Department of Earth Sciences, Univ of Southern California, 3651 Trousdale Parkway, Los Angeles, CA 90089-0740, hli@usc.edu, KU, Teh-Lung, Earth Sciences, Univ Southern California, 3651 University Ave, Los Angeles, CA 90089-0740, YOU, Chen-Feng, Department of Earth Sciences, National Cheng-Kung Univ, TaiNan, 701, Taiwan, CHENG, Hai, Department of Geology and Geophysics, Univ of Minnesota, Minneapolis, MN 55455, and EDWARDS, R. Lawrence, Department of Geology & Geophysics, Univ of Minesota, Minneapolis, MN 55455

Limestone cave deposits (speleothems) provide archives for past changes in regional temperature, precipitation and moisture source over a range of time scales. To effectively read these archives requires the establishment of proxies other than the commonly used d18O and d13C in speleothem calcite. The concentration and isotopic composition of strontium (Sr/Ca and 87Sr/86Sr) in speleothems are such proxies that have been explored. In this study, we report further effort in the use of these strontium signals in speleothem calcite to deduce the time variation of the 87Sr/86Sr ratio in sediments overlying a limestone cave. We show that this ratio reflects climate-driven variations in the provenance and the extent of chemical weathering of the epikarstic sediments. Speleothems that grew in central China under a warm and wet climate have relatively high 87Sr/86Sr but low Sr/Ca ratios. From the measurements of d18O, d13C, Sr/Ca, and 87Sr/86Sr made on a stalagmite from Buddha Cave near the Loess Plateau in central China, we reconstruct the variability of the East Asian Monsoon for portions of the time range between 70 and 280 kyr ago, showing that more intense summer monsoons prevailed during interglacial periods than during glacial periods.

2004 Denver Annual Meeting (November 7–10, 2004)
General Information for this Meeting
Session No. 29
Paleoclimatology/Paleoceanography II
Colorado Convention Center: 708/710/712
1:30 PM-5:30 PM, Sunday, November 7, 2004

Geological Society of America Abstracts with Programs, Vol. 36, No. 5, p. 90
© Copyright 2004 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.