Geologic units in San Saba county, Texas

Strawn Group (Middle Pennsylvanian; Atoka and Des Moines Series) at surface, covers 28 % of this area

Strawn Group

Tanyard Formation (Early Ordovician) at surface, covers 16 % of this area

Tanyard Formation

Gorman Formation (Early Ordovician) at surface, covers 14 % of this area

Gorman Formation

Marble Falls Limestone (Pennsylvanian; Morrow Series) at surface, covers 10 % of this area

Marble Falls Limestone

Wilberns Formation showing San Saba Member (Late Cambrian) at surface, covers 5 % of this area

Wilberns Formation showing San Saba Member

Terrace deposits (Pleistocene and Holocene) at surface, covers 5 % of this area

Terrace deposits

Smithwick Formation (Middle Pennsylvanian; Atoka Series) at surface, covers 4 % of this area

Smithwick Formation

Wilberns Formation showing Point Peak, Morgan Creek Limestone, and Welge Sandstone Members, undivided (Late Cambrian) at surface, covers 3 % of this area

Wilberns Formation showing Point Peak, Morgan Creek Limestone, and Welge Sandstone Members, undivided

Hickory Sandstone Member (Middle Cambrian) at surface, covers 3 % of this area

Hickory Sandstone Member

Honeycut Formation (Early Ordovician) at surface, covers 3 % of this area

Honeycut Formation

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

Alluvium

Barnett Formation, Chappel Limestone, Houy, Zesch, Bear Spring, and Stribling Formations, and Pillar Bluff Limestone, undivided (Late; Middle; and Early Mississippian and Devonian) at surface, covers 2 % of this area

Barnett Formation, Chappel Limestone, Houy, Zesch, Bear Spring, and Stribling Formations, and Pillar Bluff Limestone, undivided

Riley Formation showing Lion Mountain Sandstone and Cap Mountain Limestone Members, undivided (Middle Cambrian) at surface, covers 2 % of this area

Riley Formation showing Lion Mountain Sandstone and Cap Mountain Limestone Members, undivided

Travis Peak Formation (Early Cretaceous) at surface, covers 1 % of this area

Travis Peak Formation

Valley Spring Gneiss (preCambrian (Proterozoic)) at surface, covers 0.7 % of this area

Valley Spring Gneiss

Quaternary deposit, undivided (Quaternary) at surface, covers 0.5 % of this area

Quaternary deposit, undivided

Edwards Limestone (Early Cretaceous) at surface, covers 0.4 % of this area

Edwards Limestone

Packsaddle Schist (preCambrian (Proterozoic); Llano Series) at surface, covers 0.2 % of this area

Packsaddle Schist

High gravel deposits (Pleistocene) at surface, covers < 0.1 % of this area

High gravel deposits

Younger granitic intrusion (preCambrian (Proterozoic)) at surface, covers < 0.1 % of this area

Younger granitic intrusion