USGS Home
Contact USGS
Search USGS

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

Geologic units in Edwards county, Texas

alluvium (Phanerozoic | Cenozoic | Quaternary | Holocene) at surface, covers 0.3 % of this area

alluvium

Lithology: sand; silt; clay or mud; gravel

Devils River Limestone (Phanerozoic | Mesozoic | Cretaceous-Early [Comanchean]) at surface, covers 25 % of this area

Devils River Limestone

Lithology: limestone; dolostone (dolomite); chert

Salmon Peak Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 3 % of this area

Salmon Peak Limestone

Lithology: limestone; mudstone; chert

Bouquillas Formation (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 0.4 % of this area

Bouquillas Formation

Lithology: limestone; shale; mudstone; siltstone

Buda Limestone and Del Rio Clay, undivided (Phanerozoic | Mesozoic | Cretaceous-Late) at surface, covers 1 % of this area

Buda Limestone and Del Rio Clay, undivided

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

Edwards Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 61 % of this area

Edwards Limestone

Lithology: limestone; dolostone (dolomite); chert

land slide deposits (Phanerozoic | Cenozoic | Quaternary | Pleistocene Holocene) at surface, covers < 0.1 % of this area

land slide deposits

Lithology: landslide

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

Eagle Ford Formation

Lithology: shale; siltstone; limestone

Glen Rose Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 3 % of this area

Glen Rose Limestone

Lithology: limestone; clay or mud; sandstone; conglomerate

Buda Limestone (Phanerozoic | Mesozoic | Cretaceous-Early) at surface, covers 5 % of this area

Buda Limestone

Lithology: limestone

Austin Chalk (Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]) at surface, covers < 0.1 % of this area

Austin Chalk

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

Quaternary deposit, undivided (Phanerozoic | Cenozoic | Quaternary) at surface, covers 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