Official estimates of United States coal resources published during the past 15 years vary from less than 1.5 to 3.5 trillion metric tons (1.7 to 3.9 trillion short tons). These differences imply that a high degree of uncertainty exists in resource assessment.

The Nacatoch Formation of the East Texas Basin is the middle formation of the Navarro Group and consists of marine sandstones and mudstones derived largely from source areas to the northwest, north, and northeast of the East Texas Embayment.

The Frio Formation is one of the major Tertiary progradational wedges of the Texas Gulf Coast Basin and has yielded nearly 6 billion bbl of oil and 60trillion ft30f gas.

Mobilization of the Louann Salt created the present structural configuration in the central part of the East Texas Basin and was the major control on hydrocarbon accumulation in the area. Salt-cored anticlines, turtle-structure anticlines, and salt diapirs were produced by flow of salt.

The Palo Duro Basin seemingly has all the elements necessary for hydrocarbon generation and accumulation: reservoirs, traps, source rocks, and sufficient thermal maturity. Porous facies in pre-Pennsylvanian, Pennsylvanian, and Permian strata are potential hydrocarbon reservoirs.

Integrated study of the basin structure, tectonic history, rock physics, physical stratigraphy, hydrogeology, geochemistry, natural resources, and geomorphology of the Palo Duro and Dalhart Basins in the Texas Panhandle is part of a national evaluation of ancient salt basins as potential sites fo

The Oakville Formation consists of sediments deposited by several major fluvial systems that traversed the Texas Coastal Plain during the Miocene Epoch.

The Fort Worth Basin, in North-Central Texas, is a late Paleozoic foreland basin that was downwarped during the Early to Middle Pennsylvanian Period in response to tectonic stresses that also produced the Ouachita Thrust Belt.

The Miocene Oakville Sandstone is a major aquifer and uranium host beneath the Texas Coastal Plain. In 1976, approximately 6,000 acre-ft of ground water were withdrawn from the Oakville for municipal use.