Valley Spring Gneiss
(preCambrian (Proterozoic)) at surface, covers 26 % of this area Valley Spring Gneiss
Town Mountain Granite
(preCambrian (Proterozoic)) at surface, covers 23 % of this area Town Mountain Granite
Packsaddle Schist
(preCambrian (Proterozoic); Llano Series) at surface, covers 22 % of this area Packsaddle Schist
Tanyard Formation
(Early Ordovician) at surface, covers 2 % of this area Tanyard Formation
Gorman Formation
(Early Ordovician) at surface, covers 0.8 % of this area Gorman Formation
Alluvium
(Holocene) at surface, covers 0.7 % of this area Alluvium
Honeycut Formation
(Early Ordovician) at surface, covers 0.5 % of this area Honeycut Formation
Red Mountain Gneiss
(preCambrian (Proterozoic)) at surface, covers 0.3 % of this area Red Mountain Gneiss
Marble Falls Limestone
(Pennsylvanian; Morrow Series) at surface, covers 0.2 % of this area Marble Falls Limestone
Mafic igneous rocks
(preCambrian (Proterozoic)) at surface, covers 0.1 % of this area Mafic igneous rocks
Smithwick Formation
(Middle Pennsylvanian; Atoka Series) at surface, covers < 0.1 % of this area Smithwick Formation
Big Branch Gneiss
(preCambrian (Proterozoic)) at surface, covers < 0.1 % of this area Big Branch Gneiss
Terrace deposits
(Pleistocene and Holocene) at surface, covers < 0.1 % of this area Terrace deposits
Lost Creek Gneiss
(preCambrian (Proterozoic)) at surface, covers < 0.1 % of this area Lost Creek Gneiss