Geologic units in Winston county, Mississippi

Wilcox formation (Eocene) at surface, covers 76 % of this area

Irregularly bedded fine to coarse sand, more or less lignitic clay and lignite; includes bauxite bearing Fearn Springs sand member at base.

Porters Creek formation (Paleocene) at surface, covers 19 % of this area

(Midway group), Dark-gray clay, north of Clay County contains slightly glauconitic, micaceous sand lenses.

Tallahatta formation and Neshoba sand (Eocene) at surface, covers 5 % of this area

(Claiborne group), Southeast of Pearl River predominantly more or less glauconitic claystone and clay with lenses of sand and some sandstone; highly cross-bedded sand at base; northwest of Pearl river predominantly sand, locally glauconitic, containing claystone and clay lenses and abundant clay stringers; Neshoba sand, sparingly glauconitic fairly coarse sand not recognized southeast of Newton County or north of Yalobusha River.

Clayton formation (Paleocene) at surface, covers 0.5 % of this area

(Midway group), Upper part, greenish-gray coarsely glauconitic sandy clay and marl; lower part, crystalline sandy limestone and loose sand, represented south of Houston by a discontinuous bed of indurated calcareous sandstone.