National Uranium Resource Evaluation: Delta Quadrangle, Utah

The Delta 10 x 20 Quadrangle, Utah contains rocks which range in age from the Precambrian through the Holocene. It lies in the eastern part of the Basin and Range Province, approximately 85 mi southwest of Salt Lake City. Most known uranium resource potential lies in four geologic environments in two geographic areas. Favorable environments are: (1) Tertiary tuffaceous sandstone and conglomerate epigenetic disseminated deposits; (2) volcanic hydroallogenic environments containing uranium-mineralized altered tephra in the beryllium tuff member of the Miocene Spor Mountain Formation; (3) pipes or small diatreme structures in the Paleozoic limestones and quartzites on Spor Mountain, defined as Tertiary volcanogenic hydroallogenic environments; and, (4) alluvial-lacustrine placer environments, on the east and west sides of the Deep Creek Range adjacent to the quartz monzonite Ibapah stock. The significant volume of Miocene rhyolites and tuffs in the Quadrangle contain uncommonly large abundances of uranium and thorium