Geologic units in Lee county, Mississippi

Demopolis chalk (Upper Cretaceous) at surface, covers 47 % of this area

(Selma group), Chalk and marly chalk containing fewer impurities than underlying and overlying formations.

Coffee sand (Upper Cretaceous) at surface, covers 37 % of this area

(Selma group), Light-gray cross-bedded to massive glauconitic sand and sandy clay and calcareous sandstone.

Mooreville chalk (Upper Cretaceous) at surface, covers 15 % of this area

(Selma group), Marly chalk and calcareous clay.

Eutaw formation (Tombigbee sand member) (Late Cretaceous) at surface, covers 2 % of this area

Massive fine glauconitic sand.

Ripley formation (Upper Cretaceous) at surface, covers < 0.1 % of this area

(Selma group), Gray to greenish-gray fine glauconitic sand, clay, and sandy limestone; south of Oktibbeha County is very sandy micaceous chalk.