National Uranium Resource Evaluation: Laredo Quadrangle, Texas

The Laredo Quadrangle, Texas, was evaluated to a depth of 1500 m to identify environments and delineate areas favorable for the occurrence of uranium deposits. The areas were delineated in accordance with criteria established by the National Uranium Resource Evaluation program sponsored by the US Department of Energy. Surface studies included investigations of uranium occurrences described in the literature, location of aerial radiometric anomalies, outcrop studies, and followup of hydrogeochemical and stream-sediment reconnaissance data. Subsurface evaluation of selected geologic units was accomplished by using electric and gamma-ray well logs to construct maps and cross sections. An environment favorable for Texas roll-type sandstone uranium deposits is identified in 62 areas in the Goliad, Oakville, Catahoula, Frio, and Whitsett Formations. The Midway Group; the Reklaw, Weches, Cook Mountain, Caddell, Wellborn, Manning, Vicksburg, and Anahuac Formations; the Chusa Member of the Catahoula Formation; the Fleming, Uvalde, Lissie, and Beaumont Formations; and river-terrace deposits and deposits of recent age are considered unfavorable. The Yegua, Sparta, Laredo, and Queen City Formations; the El Pico Clay; the Bigford and Carrizo Formations; the Wilcox Group; and the Escondido, Olmos, and San Miguel Formations were examined but not evaluated