Natural gas in the United States consists of proved reserves in known reservoirs, of inferred reserves and undeveloped resources within these reservoirs, and of undiscovered resources.

Sandstone in the Travis Peak (Hosston) Formation has been extensively modified by burial diagenesis. Permeability in much of the formation has been reduced to less than 0.1 md as a result of compaction, extensive precipitation of authigenic minerals, and minor pressure solution.

Changes in the position and stability of shorelines in the San Antonio Bay system (San Antonio, Espiritu Santo, and Mesquite Bays), Texas Gulf Coast, were documented using historical monitoring techniques.

Deep brine aquifers of the Palo Duro Basin, Texas Panhandle, ranging in depth from about 1,000 to 3,000 m below land surface, are underpressured compared with the shallow Ogallala aquifer.

Ground water that moves downward from aquifers in clastic rocks of the Triassic Dockum Group and Neogene Ogallala Formation dissolves bedded halite and anhydrite in the Upper Permian evaporite section along the perimeter of the Southern High Plains in the Texas Panhandle.

Porous and permeable strata of the Deep-Basin Brine aquifer underlie bedded evaporites that are being considered as repositories for high-level nuclear waste isolation in the Palo Duro Basin, Texas Panhandle. Formation-water samples collected from four U.S.

Permian strata in the Palo Duro Basin consist of multicyclic sequences of carbonate, nodular and laminated anhydrite, bedded halite, chaotic mudstone-halite, and terrigenous clastic sediments.

Lineament analysis was used to study the relationship between subsurface structure and surficial features in East Texas, southeastern Oklahoma, southwestern Arkansas, and northwestern Louisiana-areas of low topographic relief, moderate vegetation cover, and diverse land use.