National uranium resource evaluation, Vya Quadrangle, Nevada, Oregon, and California

The Vya 20 quadrangle occupies the northwest corner of Nevada and portions of Oregon and California. It lies in the westernmost portion of the Basin and Range Province and contains Paleozoic through Holocene rocks. A surface reconnaissance was made of all geologic environments, including 19 uranium occurrences, thought to be favorable for uranium deposits. Geochemical, radiometric, and petrographic analyses were used in the evaluation and were supplemented by water analyses and geologic mapping. Areas and environments considered favorable for uranium deposits, in accord with National Uranium Resource Evaluation criteria, include: the McDermitt caldera in the northeast of the quadrangle, favorable for hydrothermal and strata-bound deposits; the Virgin Valley area in the northcentral part of the quadrangle, favorable for strata-bound deposits; the Bottle Creek area, southwest of the McDermitt caldera, favorable for volcanogenic deposits; and the Cottonwood Basin area, in the southwest of the quadrangle, which has uranium in volcaniclastic sediments and is similar to the Virgin Valley area