| State | Texas |
|---|---|
| Name | Walnut Clay |
| Geologic age | Early Cretaceous |
| Lithologic constituents | Major
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Carbonate > Limestone (Bed)
|
| Comments | Clay, limestone, and shale; clay, calcareous; limestone, chalky, marly, nodular, thick bedded, a few hard beds with sparry calcite, massive beds of Texigryphaea common in lower part; shale as thin beds most common in upper part; thickness 125-175 ft. |
| References | Bureau of Economic Geology, 1970, Waco 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 | Bell - Bosque - Brown - Burnet - Comanche - Coryell - Erath - Hamilton - Hood - Johnson - Lampasas - McLennan - Mills - Parker - Somervell - Tarrant - Travis - Williamson |