| State | Texas |
|---|---|
| Name | Lower part of Washita Group |
| Geologic age | Early Cretaceous; Comanchean Series |
| Lithologic constituents | Major
Sedimentary > Carbonate > Limestone (Bed)
Unconsolidated > Marl (Bed)
|
| Comments | On Dallas Sheet, Denton Clay is calcar, argillaceous ls. in upper part with abdt Gryphaea, brn-gray-yellow; thickness 3-11 ft. Fort Worth Ls is limest. and marl; ls. chalky, med. grained, farily hard, nodular, bluish-white to bluish-gray, interbedded with lt. gray marl; thickness 25-35 ft. Duck Creek Ls. is limest.and marl; ls, med bedded,nodular to wavy bedded, gray, interbedded with marly clay; more resistant than For Worth Ls; thickness 25-30 ft. |
| Stratigraphic units | (descending) Denton Clay,Fort Worth Limestone,Duck Creek Limestone |
| 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, 1972, Dallas 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 | Bosque - Coryell - Hamilton - Hill - McLennan |