Glen Rose Limestone (TXKgr;0)

State	Texas
Name	Glen Rose Limestone
Geologic age	Phanerozoic \| Mesozoic \| Cretaceous-Early
Original map label	Kgr
Comments	In Western part of Trans-Pecos alternating resistent ls. ledges and soft marls. Includes basal Cretaceous conglo. Present in Solitario Uplift and in Horshoe Mesa-Pine Mtns area. 335-500 ft in Big Bend Natl Park, 733 ft measured in Black Gap area (Emory Peak-Presidio Sheet) In North, central, and south Texas including Quaternary for all of west Texas- Brownwood Sheet (1976)--Glen Rose Limestone- limestone, clay, and sand alternating, some sandstone. Stairstep topography. Limest. is aphanitic to fine grained, argillaceous, silty, local dolostone beds, limest. resistant, or chalky to hard, surfaces nodular, distinctly bedded, foraminifera and marine megafossils molluscan steinkerns, rudistids, oysters, and echinoids common. Sand, thinbedded, brn-yell, gray. Clay and claystone is in part sandy, marly, recessive; sand is gray to brn-yell. thickness 40-400 ft. stated to be about 800 ft in Seguin Sheet (1974), 1,750 ft thick in subsurface of northern Maverick Co., TX. In Eastern part of Trans-Pecos and High Plains- limestone, clay, and sand. Limestone clayey, silty, sandy, thin beds, brownish yellow. Clay in part sandy. thickness 40 ft on Sherman Sheet (1967).
Primary rock type	limestone
Secondary rock type	clay or mud
Other rock types	sandstone; conglomerate
Lithologic constituents	Major Sedimentary > Carbonate > Marlstone (Bed) Sedimentary > Carbonate > Limestone (Bed) Minor Sedimentary > Clastic > Mudstone > Claystone (Bed) Sedimentary > Clastic > Sandstone (Bed) Incidental Sedimentary > Clastic > Conglomerate (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, 1976, Brownwood sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000. Bureau of Economic Geology, 1967, Sherman Sheet, Geologic Atlas of Texas: University of Texas at Austin, 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, 1974, San Antonio Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1974, Seguin Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000.
Geographic coverage	Bandera - Bell - Bexar - Blanco - Bosque - Brewster - Brown - Burnet - Comal - Comanche - Coryell - Eastland - Edwards - Erath - Gillespie - Hamilton - Hays - Hood - Jack - Johnson - Kendall - Kerr - Kimble - Kinney - Lampasas - Medina - Mills - Palo Pinto - Parker - Real - Somervell - Travis - Uvalde - Williamson - Wise