Geologic units in Dallas county, Texas

Austin Chalk (Late Cretaceous; Gulfian Series) at surface, covers 41 % of this area

Austin Chalk

Ozan Formation (Late Cretaceous; Gulfian Series) at surface, covers 17 % of this area

Ozan Formation

Alluvium (Holocene) at surface, covers 16 % of this area

Alluvium

Terrace deposits (Pleistocene and Holocene) at surface, covers 15 % of this area

Terrace deposits

Eagle Ford Formation (Late Cretaceous) at surface, covers 11 % of this area

Eagle Ford Formation

Woodbine Formation (Late Cretaceous; Gulfian Series) at surface, covers 0.1 % of this area

Woodbine Formation

Wolfe City Formation (Late Cretaceous; Gulfian Series) at surface, covers < 0.1 % of this area

Wolfe City Formation