Geologic units in Covington county, Mississippi

Pascagoula and Hattiesburg formation (Miocene) at surface, covers 74 % of this area

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

Catahoula formation (Miocene) at surface, covers 16 % 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 11 % 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".