Penholoway Formation

Similar to Cape May, broad lateral extent underlying terraces in the Carolinas; swamps and ridges on terrace surface were originally barrier islands and back bays. Superimposed on these landforms are swarms of Carolina bays.
State South Carolina
Name Penholoway Formation
Geologic age Pleistocene
Lithologic constituents
Major
Unconsolidated > Fine-detrital > ClayUnit consists of clayey sand and clay facies; silty to sandy clay, medium-gray to medium bluish-gray, weathers to very light gray, frequently well laminated. Unit is up to 15 feet (5 meters) thick.
Unconsolidated > Coarse-detrital > SandUnit consists of clayey sand and clay facies; silty to sandy clay, medium-gray to medium bluish-gray, weathers to very light gray, frequently well laminated. Unit is up to 15 feet (5 meters) thick.
Comments Secondary unit description from USGS Lexicon (ref.SC003): Penholoway Formation of Pleistocene age is used in SC. Unit consists of clayey sand and clay facies; silty to sandy clay, medium-gray to medium bluish-gray, weathers to very light gray, frequently well laminated. Unit is up to 15 feet (5 meters) thick.
References

Newell, Wayne L., Prowell, David (retired), Krantz, David, Powars, David, Mixon, Robert (retired), Stone, Byron, and Willard, Debra, in review, Surficial Geology and Geomorphology of the Atlantic Coastal Plain: USGS Open File Report, in press.

USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/

https://ngmdb.usgs.gov/Geolex/search

Counties Aiken - Allendale - Bamberg - Barnwell - Berkeley - Charleston - Chesterfield - Colleton - Dillon - Dorchester - Florence - Georgetown - Hampton - Horry - Jasper - Marion - Marlboro - Williamsburg