INVESTIGATIONS INTO SOUTH CAROLINA’S OUTER CONTINENTAL SHELF (OCS) RESOURCES: IDENTIFICATION AND MAPPING OF PALEOLANDSCAPES OFFSHORE SOUTH CAROLINA USING NEW GEOPHYSICAL DATA

With the passing of Hurricane Sandy in 2012, the Bureau of Ocean Energy Management (BOEM) instituted several studies to better understand offshore resources on the outer continental shelf (OCS) areas of the United States. This particular project highlights several of those studies in South Carolina, initiated by BOEM (1) through South Carolina (SC) Sea Grant to partnering universities, (2) through the State Geological Survey to the University of Charleston (UofC), and (3) through ongoing offshore studies at UofC on coastal zone issues and questions. New data used for this presentation, collected by BOEM contractors and academia, include ~750 trackline km of high-resolution chirp subbottom profiler, ~1400 trackline km of magnetic data, ~750 km2 of sidescan sonar data, and approximately ~330 km² of multibeam bathymetry data, with more inshore areas sea-truthed by 19 new cores. Older data collected by the UofC through (3) above included ~455 km of chirp and 82 km² of sidescan data in State waters. The new data sets were processed and interpreted at U. of SC and UofC. Data are being used to outline the paleogeography, potential human habitation sites, and sand resources on the SC-OCS. The focal areas are within the 3 to 8 nautical mile (nm) range off of Little River, Cape Romain, and Folly Beach, SC with 3 additional coverage blocks located approximately 11 nm east of Little River, SC. The more-recent unconsolidated materials were studied and numerous surface features and channels were found across the survey areas. In addition, hardbottom outcrops were noted offshore of Little River in the survey blocks past the 11nm line. Several subsurface paleochannels/valleys were identified and are possibly related to Pleistocene low-level stand river channeling as well as braided stream formation during glacial maxima. Further research will be conducted once the surveys are completed and compiled, and will be merged with previous data sets to build a more complete geomorphological understanding of the South Carolina OCS.