Upson Clay

Upson Clay
State Texas
Name Upson Clay
Geologic age Late Cretaceous; Gulfian Series
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Claystone (Bed)
Comments In Kinney and Maverick Cos., TX, Clay, sl. calcareous, dark gray to greenish gray; weathers yell-gray; marine megafossils include Exogyra ponderosa; thickness as much as about 500 ft, thins northward. Lowest part of Taylor Group.
Stratigraphic units Taylor Group
References

Dumble, E.T., 1892, Notes on the geology of the valley of the middle Rio Grande: Geological Society of America Bulletin v. 3, p. 219-230.

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.

NGMDB product
Counties Kinney - Maverick