A COMPOSITE STRATIGRAPHIC SECTION OF CENOZOIC UNITS FROM THE SOUTH CAROLINA COASTAL PLAIN NEAR CHARLESTON, SC

The South Carolina Coastal Plain consists of a thick seaward-dipping wedge of Late Cretaceous to Holocene siliciclastic and carbonate sediments overlying Paleozoic and Mesozoic crystalline basement rocks. The Lower Coastal Plain extends from the Surry Scarp located approximately fifty miles inland eastward to the present day shoreline. The lithology, thickness and distribution of the underlying Tertiary stratigraphic units have been controlled by regional tectonics, marine inundation accompanied by erosional truncation, and periods of subaerial exposure and fluvial erosion. Tertiary strata vary in composition from Paleogene age mudstones, sandstones and limestones of the Black Mingo Group, to predominantly calcareous sediments of Eocene to Oligocene age (Santee and Cooper Groups) that are in turn overlain by Neogene siliciclastic formations. Core sections that have been collected from these various lithologic units reveal the complex and diverse depositional and climatic conditions under which they were formed.

A composite Cenozoic section showing characteristic lithologies of all Cenozoic formations will be presented. This section is constructed from core and some outcrop samples. Nearly continuous cores were obtained using wire-line methods from South Carolina Coastal Plain sites by the U.S. Geological Survey. These cores were obtained in support of several projects including fundamental stratigraphic studies and aquifer storage recovery projects. This composite section is based on samples from the following cores: CHN-733 (South Windermere ASR); CHN-800 (Charleston peninsula); CHN-802 (Moore’s Landing); CHN-803 (Santee Coastal Reserve).