| Paper No. 140-1 | ||
| Presentation Time: 8:00 AM-8:15 AM | ||
| LATE PLEISTOCENE PALEOCLIMATE IN THE BLACK HILLS OF SOUTH DAKOTA FROM ISOTOPE RECORDS IN SPELEOTHEMS | ||
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FORD, Derek C., School of Geography and Geology, McMaster Univ, 1280 Main Street WEst, Hamilton, ON L8S4K1, Canada, dford@mcmail.cis.mcmaster.ca, SEREFIDDIN, Feride, Geography and Geology, McMaster Univ, 1280 Main Street West, Hamilton, ON L8S4M1, Canada, SCHWARCZ, Henry Philip, McMaster Univ, 1280 Main St W, Hamilton, ON L8S 4M1, Canada, and BALDWIN, Steve, 25260 Ridge View Road, Custer, SD 57730 We report TIMS and ICP/MS U-series dated records of d18Oct for speleothems which grew in Reed's Cave, SD (central N. America) during the Wisconsin glacial period. Coeval speleothems exhibit offsets in d18Octshowing that different drip sites in a cave respond differently to climate change. The opposite sign of d(d18Oct)/dT for samples 99902 and 20000 reflect a complex hydrological system in Reed's Cave that shows varying seasonal bias at multiple drip sites. Similar shifts in climate from interglacial to glacial conditions in the mid-continent are displayed in speleothems from Reed's Cave and Crevice Cave but local conditions have significant influence on the small-scale variations in d18Oct . U-series ages for the d18Oct record at Reed's Cave provide an independent chronology for Heinrich events and Dansgaard-Oeschger oscillations that are present in these records. Spectral analysis reveals millennial-scale variations also seen in Greenland ice cores. Data from Reed's Cave speleothems suggest that there is very little lag between climate responses in North Atlantic and central North America. Rapid changes in the size and extent of the ice sheets may be seen more promptly in the speleothem records. | ||
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2002 Denver Annual Meeting (October 27-30, 2002)
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| Session No. 140 Isotopic and Elemental Tracers of Late Quaternary Climate Change Colorado Convention Center: C105/107 8:00 AM-12:00 PM, Tuesday, October 29, 2002 | ||
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