Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > South Carolina Geology
Geologic units in Dillon county, South Carolina
- Black Creek Formation (Cretaceous) at surface, covers 1 % of this area
Black Creek Formation - clay, gray to black, lignitic; contains thin beds and laminae of fine-grained micaceous sand and thick lenses of cross-bedded sand. Glauconitic, fossiliferous clayey sand lenses in upper part.
- Swamp (Quaternary) at surface, covers < 0.1 % of this area
Swamp: Extensive cypress swamps occur in low-lying poorly-drained bay deposits. Limit of cypress is southern Delaware; from NJ south to Georgia. Atlantic white cedar is original species. Commonly extensive thick peat and buried wood.
- Bear Bluff Formation (Pliocene) at surface, covers 51 % of this area
Bear Bluff Formation: One of the older coastal terrace sequences in the Carolinas. Equivalent to Windsor Fm.
- Waccamaw Formation (Pleistocene) at surface, covers 4 % of this area
Waccamaw Formation: Another Carolina costalized terrace of early-middle Pleistocene age. Deeply weathered.
- Duplin Formation (Pliocene) at surface, covers 22 % of this area
Duplin Formation: Coastal terrace of Carolinas. Pliocene equivalent to Yorktown. Deeply weathered.
- Penholoway Formation (Pleistocene) at surface, covers 5 % of this area
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.
- Alluvial Valley Swamp (Quaternary) at surface, covers 12 % of this area
Alluvial Valley Swamp: Unconformable on all underlying units, fluvial sand and gravel at base, grading upwards into fine sands and silts, local peat. May be overrun with recent sediments from forest cutting and agriculture.
- Socastee Formation (Pleistocene) at surface, covers 4 % of this area
Socastee Formation: Low coastal formation in Carolinas like Penholoway but younger and lower in altitude.
- Yorktown Formation and Duplin Formation, Undivided (Tertiary) at surface, covers 0.3 % of this area
Yorktown Formation and Duplin Formation, Undivided - Yorktown Formation: fossiliferous clay with varying amounts of fine-grained sand, bluish gray, shell material commonly concentrated in lenses; mainly in area north of Neuse River. Duplin Formation: shelly, medium- to coarse-grained sand, sandy marl, and limestone, bluish gray; mainly in area south of Neuse River.