State | Texas |
---|---|
Name | Igneous rocks of Austin age |
Geologic age | Late Cretaceous |
Lithologic constituents |
Major
Igneous > Volcanic > Mafic-volcanic > Basalt (Pyroclastic, Flow)
Incidental
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basalt
|
Comments | Alkalic basalt, and pyroclastic rocks altered to nontronite; in form of sills, laccoliths, volcanic necks, and dikes |
References | Bureau of Economic Geology, 1974, San Angelo Sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000.Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000. |
NGMDB product | |
Counties | Kinney - Travis - Uvalde - Zavala |