|Geologic age||Early Cretaceous; Comanchean Series|
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Clastic > Mixed-clastic > Conglomerate-sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
|Comments||On Llano Sheet (1981) overlies Cow Creek limestone, Paleozoic or older rocks. In same statig position as Antlers Sand on Brownwood Sheet (1976). Is basal member, or underlies, or is shoreward facies of Glen Rose Limestone. Sand in lower part; conglo., sandst., sandy ls., and sandy, calcareous black shale interbedded with black shaly ls. and dense fossilif. blk to lt-brn ls. in upper part. cycads locally; Thickness 40-183 ft (Cuyler, 1939, p. 633-635) and about 340 ft (Imlay, 1944). According to Hill (1901, p. 141-144) in descending order: marly ls. 40 ft; siliceous ls. underlain by calc. sand 55 ft; yell calc sand, 15 ft; conglo. 25 ft; red sand 3 ft; friable yell sand 5 ft. Total thickness 143 ft.|
|Stratigraphic units||member of Travis Peak Formation or Pearsall Formation or Shingle Hills Formation|
Imlay, R.W., 1944, U.S. Geological Survey Oil and Gas Investigations Preliminary Chart 3.
Cuyler, R.H., 1939, American Association of Petroleum Geologists Bulletin, v. 23, no. 5, p. 633-635.
Hill, R.T., 1901, U.S. Geological Survey 21st Annual Report, pt. 7, p 141-144, 152.
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.
|Counties||Blanco - Burnet - Comal - Gillespie - Hays - Kendall - Kimble - McCulloch - Mason - Menard - Travis|