Near-surface lignite resources in Texas, or those under less than 200 feet (61 m) of cover, are ample to meet the state's demand for lignite in this century.
Oil and gas production in Texas peaked in 1972, but the state still contributed 28 percent of oil production and 33 percent of gas production in the United States in 1984.
In the subsurface and at the outcrop, waters in argillaceous deposits of the Calvert Bluff Formation (lower Eocene, Wilcox Group) are brackish to saline.
Cores from deep stratigraphic test wells provide an excellent basis for determination of source-rock quality and thermal maturity of potential hydrocarbon source rocks in the Palo Duro Basin. Total organic carbon (TOC) content in Pennsylvanian and Wolfcampian rocks is highest in basinal shales.
Topographically controlled ground-water-basin divides, established during the Pleistocene by erosion of the Pecos and Canadian River valleys, prevent ground-water recharge in the outcrop of the Triassic Dockum Group from entering the confined part of the aquifer in the Dockum Group beneath the So