Geologic units in Webb county, Texas

Jackson Group, undivided (Oligocene and Eocene) at surface, covers 22 % of this area

Jackson Group, undivided

Yegua Formation (Middle Eocene) at surface, covers 17 % of this area

Yegua Formation

Laredo Formation (Middle Eocene) at surface, covers 17 % of this area

Laredo Formation

El Pico Clay (Eocene) at surface, covers 16 % of this area

El Pico Clay

Goliad Formation (Miocene) at surface, covers 6 % of this area

Goliad Formation

Alluvium (Holocene) at surface, covers 5 % of this area

Alluvium

Terrace deposits (Pleistocene and Holocene) at surface, covers 4 % of this area

Terrace deposits

Bigford Formation (Eocene) at surface, covers 3 % of this area

Bigford Formation

Quaternary deposit, undivided (Quaternary) at surface, covers 3 % of this area

Quaternary deposit, undivided

Uvalde Gravel (Pliocene to Pleistocene) at surface, covers 3 % of this area

Uvalde Gravel

Sand sheet deposits (Holocene) at surface, covers 2 % of this area

Sand sheet deposits

Frio Clay (Oligocene) at surface, covers 1 % of this area

Frio Clay

Catahoula Formation (Oligocene) at surface, covers 0.7 % of this area

Catahoula Formation

Carizzo Sand (Eocene) at surface, covers 0.4 % of this area

Carizzo Sand

Indio Formation (Paleocene to Eocene) at surface, covers 0.3 % of this area

Indio Formation

Catahoula Formation and Frio Clay, undivided (Oligocene) at surface, covers < 0.1 % of this area

Catahoula Formation and Frio Clay, undivided