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URANIUM MINERALIZATION AT THE MIDNITE MINE, SPOKANE, WASHINGTON

Journal Article · · Economic Geology and the Bulletin of the Society of Economic Geologists (U.S.)

The Midnite Mine is located approximately 35 air miles nonthwest of Spokane, Washington, near the confluence of the Columbia and Spokane Rivers on the Spokane Indian Reservation. Uranium mineralization occurs in a zone along the contact between the Cretaceous Loon Lake granite and Precambrian metasediments. Ores appear to be found within and near associated fractures and shear zones. Secondary. oxidized uranium minerals, principally autunite and meta- autunite, lie above a fluctuating water table. while below this water table there occurs a zone of partially oxidized, sooty and compact uraninite. Sulfide mineralization is associated with the uraninite. Associated zones of argillic alteration that contain kaolinite, illite, montmorillonite and intermingled adularia further indicate the action of hydrothermal solutions. Botryoidal masses of marcasite and shrinkage cracks in the uraninite imply colloidal precipitation in the formation of the primary uranium ore. Ore deposition is inferred to have taken place at temperatures on the order of 300 deg C in a neutral or slightly acidic environment. (auth)

Research Organization:
Originating Research Org. not identified
Sponsoring Organization:
USDOE
NSA Number:
NSA-15-015872
OSTI ID:
4033902
Journal Information:
Economic Geology and the Bulletin of the Society of Economic Geologists (U.S.), Journal Name: Economic Geology and the Bulletin of the Society of Economic Geologists (U.S.) Vol. Vol: 56; ISSN ECGLA
Country of Publication:
Country unknown/Code not available
Language:
English