Geologic units in Hemphill county, Texas

Ogallala Formation (Pliocene to Miocene) at surface, covers 66 % of this area

Ogallala Formation

Dune sand sheet deposits (Holocene) at surface, covers 15 % of this area

Dune sand sheet deposits

Sand sheet deposits (Holocene) at surface, covers 9 % of this area

Sand sheet deposits

Alluvium (Holocene) at surface, covers 6 % of this area

Alluvium

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

Terrace deposits

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

Quaternary deposit, undivided

Blackwater Draw Formation (Pleistocene) at surface, covers 0.4 % of this area

Blackwater Draw Formation

Quartermaster Formation and Whitehorse Group, undivided (Permian; Guadalupe Series) at surface, covers 0.1 % of this area

Quartermaster Formation and Whitehorse Group, undivided