| State | South Carolina |
|---|---|
| Name | Peedee Formation - Black Creek Group, undivided |
| Geologic age | Cretaceous |
| Lithologic constituents |
Major
Unconsolidated > Coarse-detrital > SandPeedee Formation: Consists of dark-green or gray, finely micaceous, more or less glauconitic and argillitic sand, many layers of which are calcareous (impure limestone). Irregular concretionary masses of impure calcium carbonate occur in places. Dark marine clays are interstratified with sand. Black Creek Group: Consists of irregularly bedded, laminated, carbonaceous clays and thin laminae and lenses of sand; lignite and pyrite present; glauconitic in places; massive interbedded layers of glauconitic sand present toward top of unit. Light-colored clays and coarse arkosic sands also found
Unconsolidated > Fine-detrital > ClayPeedee Formation: Consists of dark-green or gray, finely micaceous, more or less glauconitic and argillitic sand, many layers of which are calcareous (impure limestone). Irregular concretionary masses of impure calcium carbonate occur in places. Dark marine clays are interstratified with sand. Black Creek Group: Consists of irregularly bedded, laminated, carbonaceous clays and thin laminae and lenses of sand; lignite and pyrite present; glauconitic in places; massive interbedded layers of glauconitic sand present toward top of unit. Light-colored clays and coarse arkosic sands also found
Minor
Sedimentary > Carbonate > LimestonePeedee Formation: Consists of dark-green or gray, finely micaceous, more or less glauconitic and argillitic sand, many layers of which are calcareous (impure limestone). Irregular concretionary masses of impure calcium carbonate occur in places. Dark marine clays are interstratified with sand. Black Creek Group: Consists of irregularly bedded, laminated, carbonaceous clays and thin laminae and lenses of sand; lignite and pyrite present; glauconitic in places; massive interbedded layers of glauconitic sand present toward top of unit. Light-colored clays and coarse arkosic sands also found
|
| Comments | Secondary unit description from USGS Lexicon (ref.SC003): Peedee Formation: Consists of dark-green or gray, finely micaceous, more or less glauconitic and argillitic sand, many layers of which are calcareous (impure limestone). Irregular concretionary masses of impure calcium carbonate occur in places. Dark marine clays are interstratified with sand. Black Creek Group: Consists of irregularly bedded, laminated, carbonaceous clays and thin laminae and lenses of sand; lignite and pyrite present; glauconitic in places; massive interbedded layers of glauconitic sand present toward top of unit. Light-colored clays and coarse arkosic sands found in SC (Chesterfield Co. and southward) formerly called Middendorf beds by Sloan (1908) revised as Middendorf arkose member of Black Creek formation (SC only) on the basis of fossil plants. |
| 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 | Chesterfield - Darlington - Kershaw - Lancaster - Lee - Marlboro - Richland - Sumter |