INTERPRETING TRACE-METAL AND STABLE ISOTOPIC RESULTS FROM A HOLOCENE STALAGMITE FROM BUCKEYE CREEK CAVE, WEST VIRGINIA

Buckeye Creek Cave, Greenbrier County, WV, possesses several speleothems that grew throughout much of the Holocene, as has been determined through Th-230 age dating of multiple specimens.  Trace-metal ratios (Ba/Ca, Mg/Ca, Sr/Ca) and stable isotopic (d¹³C, d¹⁸O) results for stalagmite BCC-2 (200 mm long; sampled contiguously at the mm scale) are used to infer paleoenvironmental changes that occurred above the cave during the last ~7000 years.  In general, Sr/Ca and Mg/Ca ratios moderately co-vary, suggesting similar controls on concentration.  Ba/Ca ratios weakly to moderately vary inversely with Sr/Ca ratios and d¹³C.  These relationships are preliminarily interpreted to distinguish periods characterized by relatively high soil zone activity (high Ba/Ca, low Sr/Ca and d¹³C) from periods during which bedrock dissolution dominates (low Ba/Ca, high Sr/Ca and d¹³C).  The last 2000 years of the record are characterized by a large increase (decrease) in Ba/Ca (Sr/Ca), followed by a decrease in Ba/Ca, and abrupt increase and stabilization of Sr/Ca, and a prolonged increase in Mg/Ca and d¹³C.  The last 2000 years of record may reflect paleo-Indian land-use practices. Century-scale oscillations in d¹⁸O during the pre-4000 yr BP period abruptly give way to less oscillatory, slightly more depleted d¹⁸O values during the post-4000 yr BP portion of the record, suggesting a significant shift in climatic conditions ~4000 yr BP.