| State | Texas |
|---|---|
| Name | Ranger Limestone and Placid Creek Shale, undivided |
| Geologic age | Pennsylvanian; Missouri Series |
| Lithologic constituents |
Major
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
Minor
Sedimentary > Carbonate > Limestone (Bed)
|
| Comments | (Placid Shale is correct, not Placid Creek Shale named on the State Geol. Map of Texas, 1992). Ranger Ls is about 30-50 ft thick, two limestone units separated by about 12 ft of calcareous gray shale. Placid Shale includes shale, sandst., and limestone. Upper part is calcar shale alternates with calcar sandst, silty, micaceous gray sandst., crossbedded, ferruginous, channel fill locally, about 20 ft thick. Lower part shale, zone of abdt molluscs, brachiopods, coral, and crinoid columnals. Merriman Ls fine grained, lt yell, up dip appears to converge with Winchell Ls, thickness 5 ft. Limestone bioclastic, clayey, brn, possible equiv. to Merriman Ls, thickness 1-10 ft. Thickness of Placid Shale 100-150 ft |
| Stratigraphic units | Canyon Group, Merriman Limestone (unit in Placid Shale) |
| References | Bureau of Economic Geology, 1972, Abilene sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000.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 | Brown - Coleman - Comanche - Eastland - Jack - McCulloch - Palo Pinto - Stephens - Young |