The Bofecillos Mountains area of Trans-Pecos Texas contains a Tertiary volcanic vent and a varied sequence of lava flows, tuff, ash-flow tuff, and associated conglomerate, sandstone, and mudrock; after most of the volcanic activity had ceased, the area was block faulled and later dissected into a

Two distinctive subaerial physiographic features that form a substantial portion, by area, of most barrier islands along the Texas coast are the washover fan and the tidal delta. Volumetrically, washover fan deposits and tidal delta deposits form a significant part of each barrier island.

The rocks exposed in the Austin West quadrangle are Cretaceous marine limestones and clays and Quaternary alluvial deposits.

Geologic map that depicts the surface geology of Carson, Gray, and Wheeler Counties and parts of Moore, Hutchinson, Roberts, Hemphill, Potter, Randall, Armstrong, Donley, and Collingsworth Counties.

Sulfur, along with salt, coal, and limestone, is one of the basic raw materials of the chemical industry. A nation’s per capita sulfur consumption is a reliable index to its chemical production and a rough index to its standard of living.

Virgil and lower Wolfcamp rocks on the Eastern Shelf in North-central Texas are composed of several intergradational depositional systems comprising 1,200 to 1,500 feet of off-lapping, predominantly terrigenous sediments.

Upper Pensylvanian and lower Permian rocks of the Eastern Shelf in North-central Texas are composed of 10 to 15 repetitive sequences including open shelf, deltaic, fluvial, and interdeltaic depositional systems.