Geologic units in Hill county, Texas

Eagle Ford Formation (Late Cretaceous) at surface, covers 23 % of this area

Eagle Ford Formation

Ozan Formation (Late Cretaceous; Gulfian Series) at surface, covers 16 % of this area

Ozan Formation

Woodbine Formation (Late Cretaceous; Gulfian Series) at surface, covers 14 % of this area

Woodbine Formation

Austin Chalk (Late Cretaceous; Gulfian Series) at surface, covers 14 % of this area

Austin Chalk

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

Wolfe City Formation

Grayson Marl and Main Street Limestone, undivided (Early Late Cretaceous and Late Early Cretaceous) at surface, covers 9 % of this area

Grayson Marl and Main Street Limestone, undivided

Undivided part of Washita Group (Early Cretaceous; Comanchean Series) at surface, covers 6 % of this area

Undivided part of Washita Group

Terrace deposits (Pleistocene and Holocene) at surface, covers 4 % of this area

Terrace deposits

Alluvium (Holocene) at surface, covers 3 % of this area

Alluvium

Undivided part Fredericksberg Group (Early Cretaceous) at surface, covers 2 % of this area

Undivided part Fredericksberg Group

Neylandville and Marlbrook Marls, undivided (Late Cretaceous; Gulfian Series) at surface, covers 0.3 % of this area

Neylandville and Marlbrook Marls, undivided

Quaternary deposit, undivided (Quaternary) at surface, covers 0.2 % of this area

Quaternary deposit, undivided

Pecan Gap Chalk (Late Cretaceous; Gulfian Series) at surface, covers < 0.1 % of this area

Pecan Gap Chalk

Lower part of Washita Group (Early Cretaceous; Comanchean Series) at surface, covers < 0.1 % of this area

Lower part of Washita Group