MIDWESTERN SAND DUNES, GEOARCHAEOLOGY, AND LIDAR: PRELIMINARY GEOMORPHIC LANDFORM ANALYSIS OF THE SANDY SPRINGS PALEOINDIAN SITE IN THE UPPER OHIO RIVER VALLEY

Sandy Springs represents a widely cited, yet poorly understood, Paleoindian archaeological site (~11.5k – 10k RCYBP) located along the Ohio River in southeastern Adams County, Ohio. Little attention has been given to reconstructing the geomorphic history of the surrounding landscape or to the potential that late Quaternary deposits may preserve undocumented Paleoindian components. Preliminary analysis of LiDAR data illustrates that the landscape includes a series of step-like geomorphic surfaces that likely reflect a chronosequence of alluvial/outwash terraces dating from the Late Pleistocene through Holocene. Upper landforms are characterized further by relict eolian sand dunes of undetermined age that reportedly contain archaeological material. Several surficial saline springs also are known to occur in proximity to dune features. LiDAR and NRCS soils data show that dune features rim an oval-shaped low area measuring 2.5 by 0.5 km. Dune formation is especially distinctive on the south-southwestern rim region where it is ~2.4 linear km in length. Dunes display a mixed morphology that appears to include a star-like dune, a possible compound barchan dune, and a possible climbing dune that extends roughly 18 m in height above the surrounding landscape. To what degree dune morphologies are the result of depositional or erosional processes remains unknown. It is proposed that dunes reflect source bordering features associated with increased eolian sedimentation during periods of reduced vegetation cover. Possible causes of vegetation reduction include periods of increased aridity, wildfires, salinization of local water table, or water table drawdown. Finally, it is likely that periods of increased eolian sedimentation resulted in burial of downwind portions of the Paleoindian archaeological component.