Geologic units in Mills county, Texas

Walnut Clay (Early Cretaceous) at surface, covers 24 % of this area

Walnut Clay

Travis Peak Formation (Early Cretaceous) at surface, covers 20 % of this area

Travis Peak Formation

Strawn Group (Middle Pennsylvanian; Atoka and Des Moines Series) at surface, covers 18 % of this area

Strawn Group

Undivided part Fredericksberg Group (Early Cretaceous) at surface, covers 17 % of this area

Undivided part Fredericksberg Group

Paluxy Sand and Glen Rose Limestone, undivided (Early Cretaceous) at surface, covers 15 % of this area

Paluxy Sand and Glen Rose Limestone, undivided

Terrace deposits (Pleistocene and Holocene) at surface, covers 2 % of this area

Terrace deposits

Glen Rose Limestone (Early Cretaceous) at surface, covers 2 % of this area

Glen Rose Limestone

Paluxy Sand (Early Cretaceous) at surface, covers 0.8 % of this area

Paluxy Sand

Quaternary deposit, undivided (Quaternary) at surface, covers 0.7 % of this area

Quaternary deposit, undivided

Alluvium (Holocene) at surface, covers 0.6 % of this area

Alluvium