Chert reservoirs of the Lower Devonian Thirtyone Formation represent a substantial part of the hydrocarbon resource in the Permian Basin. More than 700 million barrels of oil has been produced from these rocks, and an equivalent amount of mobile oil remains.

This study offers a high-frequency sequence stratigraphic model of carbonate-ramp strata of the San Andres Formation.

Surface fissures have been observed in many desert basins in the western United States. These surface-collapse features are usually discovered after a normally dry surface has been covered with water, either by runoff from intense rainfall, by flooding, or by irrigation.

The Hueco Bolson is a segment of the Rio Grande Rift that formed as a result of late Tertiary Basin and Range deformation. The upper Tertiary Fort Hancock Formation and the upper Tertiary-Quaternary Camp Rice Formation compose the basin fill except in the deepest (western) parts of the bolson.

The Upper Devonian Woodford Formation is an organic-rich petroleum source rock that extends throughout West Texas and southeastern New Mexico and currently is generating oil or gas in the subsurface.

Unrecovered mobile oil is oil that is movable at reservoir conditions but is prevented from migrating to existing we1 l bores because of geologic complexities or heterogeneities.

Occurrences of ground-water and soil salinization are numerous in the Concho River watershed and its confluence with the Colorado River in West Texas and in other semiarid regions of Texas and the United States.

The Ellenburger Group (Lower Ordovician) of Texas is a laterally extensive peritidal carbonate shelf sequence. It forms a major deep oil reservoir, having estimated reserves of 1.15 billion barrels of oil, and it also contains an estimated 2.2 billion barrels of oil equivalent.

The East Penwell San Andres Unit produces from a depth of approximately 3,400 ft (1,040 m) on the east flank of a broad, low-relief anticline on the east side of the Central Basin Platform of the Permian Basin in Ector and Crane Counties, West Texas.