Edwards Limestone
(Early Cretaceous) at surface, covers 77 % of this area Edwards Limestone
Hensell Sand
(Early Cretaceous; Comanchean Series) at surface, covers 17 % of this area Hensell Sand
Alluvium
(Holocene) at surface, covers 2 % of this area Alluvium
Buda Limestone
(Early Cretaceous) at surface, covers 1 % of this area Buda Limestone; Eastern part of Trans-Pecos and High Plains and Western part of Trans-Pecos and North, central, and south Texas including Quaternary for all of west Texas.
Terrace deposits
(Pleistocene and Holocene) at surface, covers 0.9 % of this area Terrace deposits
Gorman Formation
(Early Ordovician) at surface, covers 0.6 % of this area Gorman Formation
Smithwick Formation
(Middle Pennsylvanian; Atoka Series) at surface, covers 0.3 % of this area Smithwick Formation
Marble Falls Limestone
(Pennsylvanian; Morrow Series) at surface, covers 0.2 % of this area Marble Falls Limestone
Buda Limestone and Del Rio Clay, undivided
(Late Cretaceous) at surface, covers 0.1 % of this area Buda Limestone and Del Rio Clay, undivided; Eastern part of Trans-Pecos and High Plains and Western part of Trans-Pecos and North, central, and south Texas including Quaternary for all of west Texas.
Tanyard Formation
(Early Ordovician) at surface, covers 0.1 % of this area Tanyard Formation
Glen Rose Limestone
(Early Cretaceous) at surface, covers 0.1 % of this area Glen Rose Limestone
Sparta Sand
(Eocene) at surface, covers < 0.1 % of this area Sparta Sand
