From abstract: Carnotite-bearing sandstone and claystone have been found in the Chadron formation of the White River group of Oligocene age in the southern part of the Slim Buttes area, Harding County, S. Dak. The carnotite is an efflorescent yellow coating on lenticular silicified sandstone. Locally, the mineralized sandstone contains 0.23 percent uranium. The uranium and vanadium ions are believed to have been derived from the overlying mildly radioactive tuffaceous rocks of the Arikaree formation of Miocene age. Analyses of water from 26 springs issuing from the Chadron and Arikaree formations along the margins of Slim Buttes show uranium contents of as much as 200 parts per billion. Meteoric water percolating through tuffaceous rocks is thought to have brought uranium and other ions into environments in the Chadron formation that were physically and chemically favorable for the deposition of carnotite.
Abstract: Most of the uranium deposits in the Uravan and Gateway mining districts are in the persistent upper sandstone stratum of the Salt Wash member of the Morrison formation. Areas in which this stratum is predominantly lenticular have been differentiated from areas in which the stratum is predominantly nonlenticular. The most favorable ground for uranium deposits is in areas of lenticular sandstone where the stratum is underlain by continuous altered greenish-gray mudstone. Ore is localized in scour-and-fill sandstone beds within favorable areas of lenticular sandstone. Regional control of the movement of ore-bearing solutions in the principal ore-bearing sandstone zone is indicated by belts of discontinuously altered mudstone transitional in a northerly and southerly direction from an area of unaltered mudstone to areas of continuously altered mudstone ; and an area of unaltered mudstone in which no ore deposits are found and an increase in size, number, and grade of ore deposits from areas of discontinuously altered to continuously altered mudstone. Discrete regional patterns of ore deposits and altered mudstone are associated with Tertiary structures; where these structures and favorable host rocks occur in juxtaposition, regional controls appear to have localized ore deposits.
This report follows the geological field studies of uranium deposits near Pumpkin Buttes in the central part of the Powder River Basin, Wyoming, and eventually moving south of the basin.
From abstract: The Happy Jack mine is in the White Canyon area, San Juan County, Utah. Production is from high-grade uranium deposits in the Shinarump conglomerate of Triassic age. The Shinarump strata range from 161/2 to 40 feet in thickness and the lower part of these beds fills an eastward-trending channel that is more than 750 feet wide and 10 feet deep.
This report presents the geologic results of an exploration program in the Lost Creek schroeckingerite deposits in northern Sweetwater County, Wyoming.
From abstract: Forty-five areas of radioactivity in New Mexico had been investigated by government geologists or reported in the geologic literature before 1952. 21 areas contained visible uranium minerals and one contained thorium minerals. The occurrences were in the northwestern, north-central, central, southwestern, and southeastern parts of the State.
From abstract: The ore deposits are in fissue veins that contain silver, nickel, cobalt, and uranium minerals. The ore minerals, which include native silver, argentite, niccolite, millerite, skutterudite, nickel skutterudite, bismuthinite, pitchblende, and sphalerite, are in a carbonate gangue in narrow, persistent veins, most of which trend northeast. Pitchblende has been identified in the Black Hawk and the Alhambra deposits and unidentified radioactive minerals were found at five other localities. The deposits that contain the radioactive minerals constitute a belt 600 to 1,500 feet wide that trends about N. 450 E. and is approximately parallel to the southeastern boundary of the monzonite porphyry stock. All the major ore deposits are in the quartz diorite gneiss close to the monzonite porphyry. The ore deposits are similar to the deposits at Great Bear Lake, Canada, and Joachimsthal, Czechoslovakia.
From abstract: In 1951 uranium deposits containing carnotite were discovered in the southern Black Hills near Edgemont, Fall River County, S. Dak. Many carnotite deposits have since been found in sandstones in the Inyan Kara group of Early Cretaceous age, and uranium-bearing material has been discovered in the Minnelusa sandstone of Pennsylvanian age and the Deadwood formation of Cambrian age in the southern Black Hills. Ore has been produced only from the Inyan Kara group, mostly within an area of about 30 square miles along the southwest flank of the Black Hills uplift between Dewey and Hot Springs, in Custer and Fall River Counties. In addition, occurrences of uranium in other parts of the Black Hills and the surrounding area are known or reported in sedimentary, igneous, and metamorphic rocks of pre-Cambrian to Tertiary age.
Abstract: The uranium deposit at the Silver Cliff mine near Lusk, Wyo., consists primarily of uranophane which occurs as fracture fillings and small replacement pockets in faulted and fractured calcareous sandstone of Cambrian(?) age. The country rock in the vicinity of the mine is schist of pre-Cambrian age intruded by pegmatite dikes and is unconformably overlain by almost horizontal sandstone of Cambrian(?) age. The mine is on the southern end of the Lusk Dome, a local structure probably related to the Hartville uplift. In the immediate vicinity of the mine, the dome is cut by the Silver Cliff fault, a north-trending high-angle reverse fault about 1,200 feet in length with a stratigraphic throw of 70 feet. Uranophane, metatorbernite, pitchblende, calcite, native silver, native copper, chalcocite, azurite, malachite, chrysocolla, and cuprite have been deposited in fractured sandstone. The fault was probably mineralized throughout its length, but because of erosion, the mineralized zone is discontinuous. The principal ore body is about 800 feet long. The width and depth of the mineralized zone are not accurately known but are at least 20 feet and 60 feet respectively. The uranium content of material sampled in the mine ranges from 0.001 to 0.23 percent uranium, whereas dump samples range from 0.076 to 3.39 percent uranium.
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