Geologic units in Brazos county, Texas

Alluvium (Holocene) at surface, covers 23 % of this area

Alluvium

Yegua Formation (Middle Eocene) at surface, covers 20 % of this area

Yegua Formation

Cook Mountain Formation (Eocene) at surface, covers 18 % of this area

Cook Mountain Formation

High gravel deposits (Pleistocene) at surface, covers 16 % of this area

High gravel deposits

Terrace deposits (Pleistocene and Holocene) at surface, covers 8 % of this area

Terrace deposits

Manning Formation (Eocene) at surface, covers 7 % of this area

Manning Formation

Cadell Formation (Eocene) at surface, covers 2 % of this area

Cadell Formation

Whitsett Formation (Oligocene and Eocene) at surface, covers 2 % of this area

Whitsett Formation

Wellborn Formation (Eocene) at surface, covers 2 % of this area

Wellborn Formation

Catahoula Formation (Oligocene) at surface, covers 1 % of this area

Catahoula Formation

Oakville Sandstone (Miocene) at surface, covers < 0.1 % of this area

Oakville Sandstone

Sparta Sand (Eocene) at surface, covers < 0.1 % of this area

Sparta Sand