|Name||Del Rio Clay and Georgetown Limestone, undivided|
|Geologic age||Late Cretaceous; Gulfian Series|
Sedimentary > Carbonate > Limestone
Unconsolidated > Fine-detrital > Clay (Estuarine)
Unconsolidated > Marl (Estuarine)
|Comments||Del Rio Clay--calcareous and gypsiferous, pyrite common, blocky, med. gray, weathers lt gray to yell-gray; some thin lenses of highly calcareous siltst.; marine megafossils include abdt Exogyra arietina and other pelecypods; thickness 40-70 ft in Austin Sheet (1974). Georgetown Limestone--limestone and marl; mostly limestone, fine grained, argillaceous, nodular, mod indurated, lt gray; some ls brittle and thick bedded, white; some shale, marly, soft, marine megafossils include Kingena wacoensis and Gryphaea washitaensis; thickness 30-80 ft, thins southward in Austin Sheet.|
|Stratigraphic units||Grayson Marl|
Bureau of Economic Geology, 1974, Austin Sheet, Geologic Atlas of Texas, University of Texas, 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.
|Counties||Hays - Travis - Williamson|