Geologic units in Donley county, Texas

Ogallala Formation (Pliocene to Miocene) at surface, covers 50 % of this area

Ogallala Formation

Quartermaster Formation and Whitehorse Group, undivided (Permian; Guadalupe Series) at surface, covers 12 % of this area

Quartermaster Formation and Whitehorse Group, undivided

Sand sheet deposits (Holocene) at surface, covers 12 % of this area

Sand sheet deposits

Whitehorse Group, undivided (Permian; Guadalupe Series) at surface, covers 11 % of this area

Whitehorse Group, undivided

Quartermaster Formation (Permian; Guadalupe Series) at surface, covers 5 % of this area

Quartermaster Formation; North and central Texas including panhandle.

Blackwater Draw Formation (Pleistocene) at surface, covers 4 % of this area

Blackwater Draw Formation

Alluvium (Holocene) at surface, covers 2 % of this area

Alluvium

Lingos Formation (Middle (?) Pleistocene to Recent) at surface, covers 2 % of this area

Lingos Formation

Dune sand sheet deposits (Holocene) at surface, covers 0.7 % of this area

Dune sand sheet deposits

Terrace deposits (Pleistocene and Holocene) at surface, covers 0.4 % of this area

Terrace deposits

Playa deposits (Pleistocene and Holocene) at surface, covers 0.1 % of this area

Playa deposits