|Geologic age||Pliocene to Miocene|
Unconsolidated > Coarse-detrital > Sand (Bed)
Unconsolidated > Fine-detrital > Clay (Bed)
Unconsolidated > Fine-detrital > Silt (Bed)
Unconsolidated > Coarse-detrital > Gravel (Bed)
|Comments||Sand, silt, clay, gravel, and caliche. Sand, fine to cs-grain quartz, silty in part, caliche nodules locally, cemented locally by calcite and by silica, locally crossbedded. Minor silt and clay with caliche nodules, sandy in places. Gravel present locally, pebbles and cobbles of quartz, quartzite, minor chert, igneous rock, metamorphic rock, limestone, clay balls in lower part, and abraded Gryphaea in intraformational channel deposits and in basal conglomerate. Caliche sandy, pisolitic, white, gray, pink comprises 4 or 5 beds up to 12 ft thick. Forms ledges and caprock. Max thickness 550 ft.|
Bureau of Economic Geology, 1969, Amarillo Sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000.
Bureau of Economic Geology, 1970, Perryton Sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, 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||Andrews - Armstrong - Bailey - Borden - Briscoe - Carson - Castro - Cochran - Coke - Collingsworth - Crosby - Dallam - Dawson - Deaf Smith - Dickens - Donley - Ector - Fisher - Floyd - Gaines - Garza - Glasscock - Gray - Hale - Hall - Hansford - Hartley - Hemphill - Hockley - Howard - Hutchinson - Kent - Lamb - Lipscomb - Lubbock - Lynn - Martin - Midland - Mitchell - Moore - Motley - Nolan - Ochiltree - Oldham - Parmer - Potter - Randall - Roberts - Scurry - Sherman - Sterling - Swisher - Terry - Tom Green - Wheeler - Winkler - Yoakum|