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Title: Summary of the geology and resources of uranium in the San Juan Basin and adjacent region, New Mexico, Arizona, Utah, and Colorado

Technical Report ·
OSTI ID:5231776

Sedimentary rocks of Jurassic age in the southern part of the San Juan Basin contain the largest uranium deposits in the United States, and offer the promise of additional uranium deposits. Elsewhere in the basin and the adjacent Colorado Plateau, reserves and resources of uranium are known primarily in Triassic, Jurassic, and Cretaceous strata. Although uranium occurs in several formations and rock types within the area, the most important uranium deposits are contained in sandstone facies of the sequence, where geochemical and sedimentological conditions were most suitable for concentration of uranium. The distribution of sandstone and other favorable facies is controlled by the special distribution and association of sedimentary depositional environments operative during past geologic periods in the basin and on the Colorado Plateau. These environments of sedimentary deposition included a variety of both marine and continental types, such as deep and shallow marine, marginal marine, evaporite basin, fluvial, lacustrine, and desert eolian and sabkha. Uranium is most commonly associated with ancient continental stream and lake deposits of Jurassic age and marginal marine deposits of Cretaceous age. Most of the 120,000 tons of U/sub 3/O/sub 8/ produced in the area came from the Westwater Canyon and Brushy Basin Members of the Morrison Formation. The largest proportion of the reserves of 465,500 tons of U/sub 3/O/sub 8/ (at $50-per-pound forward cost) are in the area between Gallup and Laguna, New Mexico. Potential uranium resources, most of which remain undiscovered, total 826,600 tons U/sub 3/O/sub 8/ at $30-per-pound forward cost and are in the southern San Juan basin. The total resource base for the basin is about 1,500,000 tons U/sub 3/O/sub 8/ at a forward cost of $50-per-pound.

Research Organization:
Geological Survey, Denver, CO (USA)
OSTI ID:
5231776
Report Number(s):
USGS-OFR-78-964; ON: DE83902369
Resource Relation:
Other Information: Paper copy only, copy does not permit microfiche production
Country of Publication:
United States
Language:
English