|Geologic age||Middle Eocene|
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Claystone (Bed)
|Comments||sandstone and clay; thick ss member in upper and lower parts, v. fine to fine grained, in part glauconitic, ferruginous, red and brown, clay in middle, weathers orange-yell. thickness 600-700 ft. correl. with Sparta Sand and Cook Mountain Formations of Clairborne Group of eastern and central TX.|
Bureau of Economic Geology, 1976, Crystal City-Eagle Pass Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, 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.
|Counties||Dimmit - Frio - La Salle - Starr - Webb - Zapata - Zavala|