Geologic units in Ellis county, Texas

Austin Chalk (Late Cretaceous; Gulfian Series) at surface, covers 35 % of this area

Austin Chalk

Ozan Formation (Late Cretaceous; Gulfian Series) at surface, covers 26 % of this area

Ozan Formation

Alluvium (Holocene) at surface, covers 11 % of this area

Alluvium

Eagle Ford Formation (Late Cretaceous) at surface, covers 11 % of this area

Eagle Ford Formation

Wolfe City Formation (Late Cretaceous; Gulfian Series) at surface, covers 9 % of this area

Wolfe City Formation

Neylandville and Marlbrook Marls, undivided (Late Cretaceous; Gulfian Series) at surface, covers 7 % of this area

Neylandville and Marlbrook Marls, undivided

Terrace deposits (Pleistocene and Holocene) at surface, covers 1 % of this area

Terrace deposits