| State | Texas |
|---|---|
| Name | Clear Fork Group |
| Geologic age | Permian; Leonard Series |
| Lithologic constituents |
Major
Sedimentary > Clastic > Mudstone > Claystone (Bed)
Incidental
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Carbonate > Dolostone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Chemical > Evaporite > Gypsum (Bed)
Sedimentary > Clastic > Siltstone (Bed)
|
| Comments | Mudstone, siltstone, sandstone, dolomite, limestone, and gypsum. Mostly mudst, commonly silty, brownish-red, minor gray, calcar. nodules abdt in lower part, vertebrate fossils locally common. Siltst in units 1-3 ft thick throughout, locally dolomitic in upper part of map unit. Sandst. reddish-brn v. fine grained to fine-grained, locally conglomeratic, crossbedded, lenticular and thin-bedded as channel fill. Dolomite in units 2 inches to 1 foot thick mostly in upper third of Clear Fork Group. Limestone gray in thin discontin. beds in lower part. Gypsum white satin spar and alabaster as thin lenses and veins in uppermost part. Thickness of Clear Fork Grp 1,200-1,400 ft |
| Stratigraphic units | Merkel Dolomite, Bullwagon Dolomite, Lytle Limestone |
| References | Bureau of Economic Geology, 1987, Wichita Falls-Lawton Sheet, Geologic Atlas of Texas: University of Texas at Austin, 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 | Baylor - Coke - Coleman - Concho - Foard - Hardeman - Haskell - Jones - King - Knox - Nolan - Runnels - Shackelford - Stonewall - Taylor - Throckmorton - Tom Green - Wichita - Wilbarger |