Geologic units in Copiah county, Mississippi

Catahoula formation (Miocene) at surface, covers 61 % of this area

Irregularly bedded gray sand and sandstone; mottled red and gray, green, and chocolate-colored clay; some quartzite, and some gravel; the Paynes Hammock sand, sandy limestone cross-bedded fine green sand, and thin-bedded sand and clay, is mapped with the underlying Chickasawhay limestone in eastern MS.

Citronelle formation (Pleistocene) at surface, covers 27 % of this area

Red sand and gravel and white clay; may be of Pliocene age; the formation mapped is equivalent to the Willis sand and does not include the terrace deposits, colluvium, and residuum commonly considered "Citronelle".

Pascagoula and Hattiesburg formation (Miocene) at surface, covers 11 % of this area

Green and bluish-green clay, sandy clay, and sand; gray siltstone and sand; locally fossiliferous.