Geologic units in Jefferson county, Mississippi

Catahoula formation (Miocene) at surface, covers 51 % 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.

Pascagoula and Hattiesburg formation (Miocene) at surface, covers 31 % of this area

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

Citronelle formation (Pleistocene) at surface, covers 10 % 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".

Alluvium (Holocene) at surface, covers 8 % of this area

Loam, sand, gravel, and clay; mapped only in Mississippi River Alluvial Plain.

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

Gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.

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

Gray and brown silt, silty clay, some very fine sand, reddish brown along the Red River.