QUATERNARY GEOMORPHOLOGY AND NEAR-SURFACE STRATIGRAPHY OF THE SOUTH CAROLINA MIDDLE TO LOWER COASTAL PLAIN

The well-preserved landscape of South Carolina’s Lower and Middle Coastal Plain provide a natural treasure-trove of emergent Quaternary coastal and fluvial depositional systems combined with an overprint of climatologically-induced landforms (dunes, Carolina bays, etc.) and those of a naturally decaying landscape (pirated river systems, entrenched drainages, abandoned rivers, etc.). This paper presents new and compiled data for ongoing geomorphic and stratigraphic studies being conducted on the Quaternary evolution of portions of the lower and middle Coastal Plain of SC. With implications to sea level change, sediment dynamics, and neotectonics, we utilize high-resolution LiDAR elevations, soils data, existing and new cores, ground penetrating radar, and seismic surveys to produce a new geomorphic map of this region with a series of local stratigraphic cross sections.

The maps are used to better understand the depositional environments and correlation of the various barrier island and fluvial systems from south to north across the region, and how these systems have been modified by subsequent exposure, erosion, and deposition across the landscape. Difficult areas for correlation are in the southern portions where large tidal estuaries separate the tightly packed series of elevated marine terraces which are separated by narrow marsh and tidal deposits. North of Charleston Harbor, the emergent barriers are more continuous. As the northern section of the coast is reached, truncation of older barriers by Pleistocene and modern barriers makes direct correlation farther north difficult.

The presented map, although inclusive for the Lower and Middle Coastal Plain of South Carolina, represents a starting point for future, more refined geomorphic, stratigraphic (chrono-, litho-, magneto-, and allostratigraphic), and neotectonic research, and points to areas where both global and regional sea level questions may be answered.