A broad zone of salt dissolution that affects parts of the Permian Salado, Seven Rivers, San Andres, Glorieta, and upper Clear Fork Formations occurs beneath the Canadian River Valley from New Mexico eastward toward Amarillo, Texas, and southeastward parallel to the eastern Caprock Escarpment. Structure contours on the base of the Tertiary Ogallala Formation show broad areas with as much as 120 m (400 ft) of relief that are attributed to salt dissolution and subsidence in the Anadarko Basin and along the northern and eastern margins of the Palo Duro and Dalhart Basins.

The environmentally sensitive trace elements molybdenum, arsenic, and selenium are concentrated with uranium in ore deposits in South Texas. Cattle grazing in some pastures in mining areas have contracted molybdenosis, a cattle disease resulting from an imbalance of molybdenum and copper. To determine natural concentrations of the elements in soils in the South Texas area and to evaluate possible effects of mining on adjacent agricultural land, two sets of soil samples were collected and analyzed for molybdenum, arsenic, selenium, and copper.

Texas lignite occurs in three Eocene (lower Tertiary) geologic units--the Wilcox Group, Jackson Group, and Yegua Formation--and in three ancient depositional systems--fluvial, deltaic, and strandplain/lagoonal. Near-surface resources in Texas at depths between 20 and 200 ft (6.1 and 61 m) in seams 3 ft (0.9 m) or thicker are 23,377 million short tons (21,208 million metric tons) and are dominantly fluvial in origin. More than 90 percent of the resources occur in the Wilcox and Jackson Groups north of the Colorado River.

Upward-coarsening sandstone units of the Upper Cretaceous San Miguel Formation in South Texas were deposited in wave-dominated deltas during minor regressive phases, periodically interrupting a major marine transgression. Sediments accumulated in the Maverick Basin within the Rio Grande Embayment. Cross sections and sandstone maps reveal that during deposition of the San Miguel, the Maverick Basin consisted of two subbasins that received sediments from the northwest and the north.