Great Divide Basin drilling project Sweetwater County, Wyoming

A six-hole drilling program conducted in the southeastern part of the Great Divide Basin, south-central Wyoming, obtained subsurface geologic data to evaluate the uranium potential of the Battle Spring Formation (Tertiary). In the Great Basin the formation consists of fluvial and lacustrine silstones, arkosic to feldspathic sandstones, and carbonaceous mudstones thought to contain intermediate-grade uranium (0.01 to 0.05% U3O8). Low-grade uranium mineralization is widespread throughout the area and generally occurs in carbonaceous mudstones interbedded with intercalated beds of coarse-grained sandstone and lignite. The close relationship between the permeability of the surrounding rocks and the uranium content of the carbonaceous units suggests that the uranium was epigenetically emplaced. All six of the drill holes penetrated thin intervals of intermediate-grade uranium mineralization