USGS Home
Contact USGS
Search USGS

Mineral Resources > Online Spatial Data > Geology > by state > Texas Geology

Geologic units in Hays county, Texas

Cow Creek Limestone, Hammett Shale, and Sycamore Sand, undivided (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 0.2 % of this area

Cow Creek Limestone, Hammett Shale, and Sycamore Sand, undivided

Lithology: limestone; shale; fine-grained mixed clastic

Eagle Ford Formation (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers < 0.1 % of this area

Eagle Ford Formation

Lithology: shale; siltstone; limestone

Ozan Formation (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]) at surface, covers 0.2 % of this area

Ozan Formation

Lithology: clay or mud

Leona Formation (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers 2 % of this area

Leona Formation

Lithology: sand; gravel; clay or mud

Hensell Sand (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean) at surface, covers 0.4 % of this area

Hensell Sand

Lithology: limestone; sand; conglomerate; shale

Pecan Gap Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]) at surface, covers 9 % of this area

Pecan Gap Chalk

Lithology: limestone; sand; clay or mud; limestone

Edwards Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 23 % of this area

Edwards Limestone

Lithology: limestone; dolostone (dolomite); chert

Terrace deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene Holocene) at surface, covers 2 % of this area

Terrace deposits

Lithology: terrace; sand; gravel; silt; clay or mud

Glen Rose Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 50 % of this area

Glen Rose Limestone

Lithology: limestone; clay or mud; sandstone; conglomerate

Onion Creek Marl (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers 0.4 % of this area

Onion Creek Marl

Lithology: sand; gravel; clay or mud

Del Rio Clay and Georgetown Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian] ) at surface, covers 3 % of this area

Del Rio Clay and Georgetown Limestone, undivided

Lithology: clay or mud; limestone

Quaternary deposit, undivided (Phanerozoic | Cenozoic | Quaternary) at surface, covers < 0.1 % of this area

sand, silt, clay, and gravel. locally indurated with calcium carbonate (caliche); includes point bar, natural levee, stream channel, sand dune, terrace, alluvial fan, landslide bolson and playa deposits

Lithology: sand ; silt ; clay or mud; gravel; carbonate

Austin Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]) at surface, covers 3 % of this area

Austin Chalk

Lithology: limestone; mudstone; clay or mud; bentonite; mudstone

alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 2 % of this area

alluvium

Lithology: sand; silt; clay or mud; gravel

Eagle Ford Formation and Buda Limestone, undivided (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 1 % of this area

Eagle Ford Formation and Buda Limestone, undivided

Lithology: fine-grained mixed clastic; limestone

Navarro Group and Marlbrook Marl, undivided (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]) at surface, covers 2 % of this area

Navarro Group and Marlbrook Marl, undivided

Lithology: clay or mud; fine-grained mixed clastic; sandstone; sand

Willis Formation (Phanerozoic | Cenozoic | Tertiary | Pliocene) at surface, covers < 0.1 % of this area

Willis Formation

Lithology: clay or mud; silt; sand; gravel

high gravel deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene) at surface, covers 0.2 % of this area

high gravel deposits

Lithology: gravel; silt; sand

Buda Limestone and Del Rio Clay, undivided (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.6 % of this area

Buda Limestone and Del Rio Clay, undivided

Lithology: limestone; mudstone; clay or mud; siltstone; shale