The Red River rises in northeastern New Mexico and extends across northern Texas and east of the Panhandle serves as the northern border of that State. The late Cenozoic geology of the Red River basin has been studied intensively in northwestern Texas and in Louisiana.

One of the basic mineral resources of Texas is abundant deposits of lignite in Eocene rocks of the Gulf Coastal Plain. Currently, Texas lignites are utilized as sources of industrial fuel, activated carbon and, locally, drilling mud additives; research indicates significant future nonfuel uses of lignite and lignitic coals.