National Uranium Resource Evaluation: Escalante Quadrangle, Utah

Seven areas favorable for the occurrence of uranium deposits meet the minimum size and grade requirements of the National Uranium Resource Evaluation of the US Department of Energy in the Escalante 10 x 20 Quadrangle, South-Central Utah. Five areas identified in the Late Jurassic Salt Wash Member of the Morrison Formation are: the Henry Mountains mineral belt, and the Bitter Creek, Cat Pasture, Carcass Canyon, and Fiftymile Point areas. The evaluation of these areas was based on the presence of the following features: fluvial sandstones deposited by low-energy streams; actively subsiding synclines; paleostream transport directions approximately perpendicular to the trend of the paleofolds; presence of favorable gray lacustrine mudstone; and known uranium occurrences associated with the favorable gray mudstones. Four favorable areas identified in the Late Triassic Chinle Formation are the White Canyon-Elk Ridge, Dirty Devil-Orange Cliffs, Monument Valley, and the Greater Circle Cliffs subareas. These areas were identified as favorable on the basis of the sandstone-to-shale ratio for the Chinle Formation, and the geographic distribution of the Petrified Forest Member of the Chinle