Uranium-bearing carbonaceous shale and lignite in the Goose Creek district, Cassia County, Idaho, Boxelder County, Utah and Elko County, Nevada

Abstract

The Goose Creek district includes about 260 miles in southern Cassia County, Idaho, and adjacent parts of Boxelder County, Utah, and Elko County Nev. The-area comprises the northern and central parts of an intermontane basin drained by northward-flowing Goose Creek and its tributaries. An essentially conformable sequence of fluviatile, lacustrine, and pyroclastic sediments of late Miocene (?) and early Pliocene age make up most of the rocks exposed in the district. These rocks include the Payette formation and the overlying, Salt Lake formation. They unconformably overlie a sequence of limestone, quartzite, and shale Carboniferous and older in age, exposed in the mountains to the west and northeast; and a thick body of rhyolite of Tertiary (?) age exposed in the mountains to the southeast. Surficial deposits of silt, sand, and gravel locally overlie the older rocks. The Payette and Salt Lake formations have a general easterly dip of 4 to 12 degrees, modified locally by shallow folds. Many normal faults, some with displacement several hundred feet, cut the Tertiary strata at various places in the district.