Geologic units in Aiken county, South Carolina

Additional scientific data in this geographic area

Huber/Lisbon/Barnwell Formations, undivided (Eocene) at surface, covers 62 % 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.

Black Creek/Cusseta/Blufftown Formations (Cretaceous) at surface, covers 22 % of this area

Moderately to poorly sorted sand and clay deposited in delta-dominated shallow marine environments. Unit is characterized by sands containing locally abundant (F-VC grained) tourmaline and (F-VC grained) muscovite with some monazite and garnet. Clay layers are also common and some lower delta plain deposits form commercial kaolin bodies. Generally very restricted marine in eastern Georgia becoming more open marine to the east and west.

Alluvial Valley Swamp (Quaternary) at surface, covers 4 % 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.

Neogene strata (undifferentiated) (Neogene) at surface, covers 4 % of this area

Poorly sorted clayey sand and gravel deposited in a fluvial environment in South Carolina but becoming more fluvio-marine in Georgia. Unit is characterized by insitu weathered feldspar and an abundance of quartzite gravel and cobbles.

Peedee Formation (Cretaceous) at surface, covers 2 % of this area

Peedee Formation

Waccamaw Formation (Pleistocene) at surface, covers 1 % of this area

Another Carolina costalized terrace of early-middle Pleistocene age. Deeply weathered.

Socastee Formation (Pleistocene) at surface, covers 1 % of this area

Low coastal formation in Carolinas like Penholoway but younger and lower in altitude.

Black Mingo/Clayton Formations (Tertiary) at surface, covers 0.9 % of this area

Poorly to well sorted sand and clay deposited in delta-dominated fluvial- and shallow marine environments. Older parts of unit are characterized by an abundance of feldspar and local sillimanite. Unit is generally delta plain and lagoon deposits in South Carolina becoming open marine calcareous sand and clay in western Georgia. In central Georgia, unit contains an abundance of commercial kaolin deposits formed in lower delta plain environments.

Penholoway Formation (Pleistocene) at surface, covers 0.9 % of this area

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.

Chenier plain and deltas of Suwannee & Chattahoochie Rivers (Holocene) at surface, covers 0.7 % of this area

Chenier plain and deltas of Suwannee & Chattahoochie Rivers

Metavolcanic and metasedimentary rocks of Bel Air Belt (Ordovician to Neoproterozoic) at surface, covers 0.4 % of this area

Metavolcanic and metasedimentary rocks of Bel Air Belt

Beach (Holocene) at surface, covers < 0.1 % of this area

Holocene beach complex sediments. Sands and gravels of littoral zone, dune system, barrier system.

Stream alluvium (Quaternary) at surface, covers < 0.1 % of this area

Stream alluvium and undifferentiated terrace deposits