Geologic units in Richland county, South Carolina

Peedee Formation - Black Creek Group, undivided (Cretaceous) at surface, covers 19 % of this area

Peedee Formation - Black Creek Group, undivided

Duplin Formation (Pliocene) at surface, covers 18 % of this area

Coastal terrace of Carolinas. Pliocene equivalent to Yorktown. Deeply weathered.

Alluvial Valley Swamp (Quaternary) at surface, covers 15 % of this area

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.

Cape Fear/Eutaw Formations (Cretaceous) at surface, covers 11 % of this area

Poorly sorted clayey sand and gravel deposited in delta-dominated fluvial- and restricted marine environments. Unit is characterized by an abundance of smoky quartz gravel, feldspar, monazite, and garnet typically concentrated in placer deposits. Generally non-marine from North Carolina to central Georgia but contains shallow-water delta-front deposits in western Georgia.

Huber/Lisbon/Barnwell Formations, undivided (Eocene) at surface, covers 10 % of this area

Poorly to well sorted sand, clay and carbonates deposited in delta-dominated fluvial- and open-marine environments. Unit is characterized by commercial kaolin bodies in older strata from westernmost South Carolina to central Georgia. Younger strata are cyclic marine deposits which deeper water facies exposed in western Georgia. Carbonate facies are locally mined in western Georgia for agricultural lime.

Persimmon Fork Formation (Cambrian to Neoproterozoic) at surface, covers 9 % of this area

Predominately metatuff

Richtex Formation (Ordovician to Middle Cambrian) at surface, covers 7 % of this area

Laminated metamudstone; contains Middle Cambrian or younger sponge spicules

Asbill Pond Formation (Middle Cambrian) at surface, covers 5 % of this area

Metamorphosed siltstones and sandstones having interbedded felsic to mafic metavolcanic rocks

Mylonitic rocks of Modoc Fault Zone (Late Paleozoic) at surface, covers 5 % of this area

Mylonite gneiss

Granite - Columbia pluton (Carboniferous to Permian) at surface, covers 0.6 % of this area

Granite - Columbia pluton

Granite - Harbison pluton (Carboniferous to Permian) at surface, covers 0.6 % of this area

Granite - Harbison pluton

Little Mountain metatonalite (Neoproterozoic) at surface, covers 0.4 % of this area

Little Mountain metatonalite

Amphibolite and amphibolite gneiss (Paleozoic to Neoproterozoic) at surface, covers 0.2 % of this area

Amphibolite and amphibolite gneiss

Peedee Formation (Cretaceous) at surface, covers < 0.1 % of this area

Peedee Formation