A HYDROGEOLOGIC FRAMEWORK OF THE UPPER ATLANTIC COASTAL PLAIN SEDIMENTS OF NORTHWEST AIKEN COUNTY, SOUTH CAROLINA

KRAMBIS, C., ckrambi@clemson.edu, CHRISTOPHER, R.A., christ7@clemson.edu, HODGES, R.A., rhodges@clemson.edu, Department of Geological Sciences, Clemson Univ., Clemson, SC 29634; and PROWELL, D.C., USGS, Atlanta, GA

A stratigraphic interpretation of Upper Coastal Plain units in the vicinity of the fall line will be the basis for developing a tenable hydrogeologic model of a single-source aquifer in northwest Aiken County, South Carolina. The stratigraphic framework will be interpreted by correlating geophysical well logs which will be related to outcrops and published geologic maps. A brief discussion of the borehole logging techniques used to obtain the geophysical data will be presented. The study also explores the hydrogeologic interactions between the Coastal Plain sediments, the underlying crystalline bedrock, and local stream discharge, as well as the interaction between the subject aquifer and the regional Coastal Plain aquifer system. The implications of such a study include a more complete understanding of the up-dip stratigraphy and the water-bearing properties of the sediments for additional groundwater resource prospects in the study area.

The Cretaceous and Tertiary sediments of the South Carolina Coastal Plain dip southeast and unconformably overlie pre-Cretaceous crystalline and sedimentary rocks. These sediments thin up-dip toward the fall line where they are dissected by streams wherein the underlying crystalline rocks of low permeability are exposed. As a result, the topography varies greatly across the study area and the undulating pre-Cretaceous unconformity may provide groundwater traps where discontinuous sand aquifers exist. These aquifers appear hydrologically isolated with respect to interaction with the regional aquifer system further down-dip, and perhaps from one another. This scenario is significantly different from the continuous regional Atlantic Coastal Plain aquifer system and has a consequence on the local availability of groundwater resources. The study proposed herein will focus on the development of a hydrogeological model to better establish groundwater occurrence in the area for the community of Breezy Hill located within the up-dip region of the Coastal Plain Province of South Carolina.