Geologic units in Somervell county, Texas

Glen Rose Limestone (Early Cretaceous) at surface, covers 35 % of this area

Glen Rose Limestone

Paluxy Sand (Early Cretaceous) at surface, covers 25 % of this area

Paluxy Sand

Walnut Clay (Early Cretaceous) at surface, covers 17 % of this area

Walnut Clay

Undivided part Fredericksberg Group (Early Cretaceous) at surface, covers 10 % of this area

Undivided part Fredericksberg Group

Terrace deposits (Pleistocene and Holocene) at surface, covers 6 % of this area

Terrace deposits

Alluvium (Holocene) at surface, covers 5 % of this area

Alluvium

Quaternary deposit, undivided (Quaternary) at surface, covers 2 % of this area

Quaternary deposit, undivided

Undivided part of Washita Group (Early Cretaceous; Comanchean Series) at surface, covers 0.6 % of this area

Undivided part of Washita Group

Twin Mountains Formation (Early Cretaceous) at surface, covers 0.2 % of this area

Twin Mountains Formation