A PLEISTOCENE PALEOENVIRONMENTAL RECORD FROM THE PIEDMONT OF SOUTH CAROLINA

We present a new paleoenvironmental record of the Flatwood School Site based on sedimentologic and palynological analysis of deeply buried organic-rich sediments from a locality in the interfluvial uplands of the Southern US Piedmont near the Greenville-Spartanburg Airport, South Carolina. This site was discovered and initially studied in the 1930s and 1940s by the Climate and Physiographic Division of the US Soil Conservation Service during their investigations of gullying and sediment-filled paleo-valleys or paleo-channels. This early research revealed a landscape of sediment-filled ancient gullies and lowlands that now occupy upland drainage interfluves. Our new research investigates a site that is one of >40 similar upland Piedmont localities situated on or near major river interfluves in NC, SC and GA ( >24 in Spartanburg County SC alone) containing buried organic-rich sediments. The current investigations focus on a paleo-channel containing >8 m of sediments exposed by a <70-year-old active gully. Colluvial and alluvial sediment exposed in the currently active 4.5 m deep gully head are preliminarily dated by 4 Infrared Stimulated Luminescence (IRSL) samples in stratigraphic order from 68 to 118 ka. An additional ~4 m of 1” push core was recovered from below these sands. From these cores, we collected five additional samples for IRSL dating. The lower 4 meters contain abundant pollen and peat, along with carbonized and uncarbonized pieces of wood interbedded with sands, silts and clays. Particle size analysis and loss-on-ignition, combined with pollen analysis, suggest that organic detritus accumulated episodically in a forested wetland environment during periods of both low and higher energy deposition in the last interglacial Marine Isotope Stage (MIS 5e). Paleoenvironmental records like these are rare in the SE US Piedmont, and thus invaluable for understanding past climates and future global warming patterns.