Marlbrook Marl
(Late Cretaceous; Gulfian Series) at surface, covers 18 % of this area Marlbrook Marl
Terrace deposits
(Pleistocene and Holocene) at surface, covers 13 % of this area Terrace deposits
Neylandville Marl
(Late Cretaceous; Gulfian Series) at surface, covers 13 % of this area Neylandville Marl
Alluvium
(Holocene) at surface, covers 11 % of this area Alluvium
Ozan Formation
(Late Cretaceous; Gulfian Series) at surface, covers 9 % of this area Ozan Formation
Nacatoch Sand
(Late Cretaceous; Gulfian Series) at surface, covers 6 % of this area Nacatoch Sand
Pecan Gap Chalk
(Late Cretaceous; Gulfian Series) at surface, covers 4 % of this area Pecan Gap Chalk
Wolfe City Formation
(Late Cretaceous; Gulfian Series) at surface, covers 3 % of this area Wolfe City Formation
Kemp clay
(Late Cretaceous; Gulfian Series) at surface, covers 0.8 % of this area Kemp clay