Ranger Limestone and Placid Creek Shale, undivided (TXPArp;0)

State	Texas
Name	Ranger Limestone and Placid Creek Shale, undivided
Geologic age	Phanerozoic \| Paleozoic \| Carboniferous Pennsylvanian [Missouri]
Original map label	IPrp
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
Primary rock type	shale
Secondary rock type	limestone
Other rock types
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed) Minor Sedimentary > Carbonate > Limestone (Bed)
Map references	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
Unit 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.
Geographic coverage	Brown - Coleman - Comanche - Eastland - Jack - McCulloch - Palo Pinto - Stephens - Young