STRATIGRAPHIC DEVELOPMENT OF A NORTHEASTERN SOUTH CAROLINA BARRIER ISLAND: WAITES ISLAND

While studies have focused on the development of the extensive wave-dominated barrier islands of the Outer Banks of North Carolina and the prominent mixed energy barriers islands of central South Carolina, few studies have examined the development of the barrier islands located between these two areas. This ongoing study examines the geologic development of Waites Island, a transitional barrier located along the northeastern South Carolina coastline. The 5 km long by 0.5 km wide island, of which Coastal Carolina University has access to the southern half, is composed of a prominent landward ridge and more seaward beach and dune system. Along the southern third of the island, high marsh separates the ridge from the current shoreline system. To understand the geologic development of the island, 22 vibracores were collected along three shore-normal transects and one shore-parallel transect, and ground penetrating radar was collected along one of the accessible shore-normal transects. Vibracores were split, photographed and visually described for color, texture, grain size, organic components and bedding. To determine age of formation, organic-rich sediments were sent off for radiocarbon analysis. Lithologic interpretation has distinguished five depositional environments: washover/barrier island; salt marsh, back-barrier intertidal, back-barrier subtidal and freshwater peat. Geomorphology and stratigraphy indicate that the main landward ridge of the island developed as washover sediments infilled back-barrier environments at ~4,400 BP.