Sandstone-type uranium deposits are among the most economic sources of uranium. Despite their significance, the tabular deposits on the Colorado Plateau and roll-front deposits in Nebraska have not been studied adequately. There are important differences between the tabular Colorado Plateau and Nebraska roll-front deposits, including their ore mineralogy, distribution and habit of ore-bodies, alteration, and mechanisms of ore deposition. The U-Pb ages of uranium minerals from the Colorado deposits indicate four stages of mineralization, spanning from the early Oligocene to late Pliocene. Uranium and V minerals include coffinite, montroseite and carnotite and are associated with both biogenic and non-biogenically precipitated sulphides. Two generations of coffinite mineralization from the Three Crow roll-front deposit in Nebraska were identified. This mineralization precipitated during the early Pliocene and late Miocene. The U-Th activity ratios of U minerals suggest a net accumulation of uranium within the limbs of the roll-front. Evolving oxidation fronts are implied by multiple sulphide generations as indicated by their delta 34S compositions.
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/23662 |
| Date | 26 June 2014 |
| Creators | Meek, Angela |
| Contributors | Fayek, Mostafa (Geological Sciences), Chakhmouradian, Anton (Geological Sciences) Kotzer, Tom (Cameco) |
| Source Sets | University of Manitoba Canada |
| Detected Language | English |
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