CLIMATE RECONSTRUCTION USING TRACE ELEMENT AND STABLE ISOTOPE SIGNATURES PRESERVED IN AN ANCIENT STALAGMITE FROM BUCKEYE CREEK CAVE, APPALACHIAN MOUNTAINS, SOUTHERN WEST VIRGINIA, USA

The proposed research will help define and refine the timing, magnitude, and duration of climate changes by evaluating variations in trace element ratios and the stable carbon and oxygen isotope ratios of a speleothem that grew from ~490 to ~630 kiloyears before present in Buckeye Creek Cave, Appalachian Mountains, southern West Virginia. Stable isotopic and trace element signatures from samples contiguously milled at a 0.5 mm interval along the growth-axis of a ²³⁴U/²³⁰Th-dated stalagmite (BCC-025) will provide an initial understanding of in the underlying causes for shifts in regional climate coinciding with contemporaneous records. Changes in speleothem δ¹⁸O signatures have previously been interpreted to reflect shifts in the seasonality of meteoric water. Speleothem δ¹³C values are linked to relative moisture shifts and, potentially, changes in overlying vegetation. Trace element compositions assist in interpreting the magnitude and importance of various controls on relative moisture and the above-cave water-rock interaction due to the additional complexities that arise from the partitioning of species into CaCO₃.