PALEO-LAKE BUCKEYE: A NEW SEDIMENTARY ARCHIVE OF PALEOENVIRONMENTAL CONDITIONS ACROSS THE PLEISTOCENE-HOLOCENE TRANSITION IN THE CENTRAL APPALACHIAN MOUNTAINS

Paleo-Lake Buckeye is a newly recognized lake that occupied a karst basin in southeastern West Virginia during the Late Pleistocene. Here, we present preliminary findings concerning the lake’s age range, extent, and stratigraphy. Our ultimate goal is reconstruction of regional Late Pleistocene climatic and paleoenvironmental changes. We established the lake’s extent using a combination of GIS and surficial geologic mapping, including sediment coring of lake and non-lake deposits.

At least nine meters of sediment accumulated near the margins of the basin, the uppermost 5.5 m of which are exposed in a modern Buckeye Creek cutbank. A further ~3.2 meters of sediment was cored below the level of the modern streambed. Although we have yet to establish a date for the bottom of the core, we obtained radiocarbon dates of 26.5 ka from the base of the cutbank and ~20 ka from near its middle, which shows that the lake existed during the last glacial maximum.

Gleyed, clayey silts dominate the lake sediments, suggesting quiet-water deposition. However, intervals of coarse sand and shale pebbles suggest periodic inflows from one of the following sources: shore ice transport, periodic avalanching, or sheetwash events. Given the proximity of boulder streams in adjacent valleys, and other periglacial features throughout the unglaciated Central Appalachians, periglacial activity and sheetwash during cold intervals seem likely depositional mechanisms.

Whereas most pollen samples from the upper half of the cutbank were too degraded for useful taxonomic identification, lower sediments are dominated by Pinus (fir), Picea (spruce), and Poaceae (grass). Future work will include additional pollen analyses, carbon isotope and x-ray geochemistries, stratigraphic correlation to speleological deposits in Buckeye Creek Cave, and further surficial geologic mapping to better constrain the lake’s history. With few such archives for the central Appalachians, this paleo-lake represents the potential to develop novel paleoenvironmental insights into the Pleistocene-Holocene transition for the region.