Sandstones uranium

Adams, S.S. Smith, R.B. 1988. Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Bendix Field Engineering Corporation, Grand Junction, Colorado NURE Report GJBX-4(81), 146 p. 

The Earth s crust contains an average selenium content of0.05-0.09 mgkg approximating that of cadmium and antimony and ranking above molybdenum, silver, mercury, and uranium. Higher concentrations of selenium are found in volcanic rock (up to 120 mgkg ), sandstone, uranium deposits and carbonaceous rocks (Elkin 1982, Fishbein 1983, Einbrodt and Michels 1984, Merian 1985, Jacobs etal. 1977). There are... 

Peterson F. and Turner-Peterson C. E. Lacustrine-humate model sedimentologic and geochemical model for tabular sandstone uranium deposits in the Morrison Formation, Utah, and application to uranium exploration. Open File Rep. U.S. geol. Surv. 80-319, 1980, 46 p. 

Sandstone uranium Intracratonic basins Continental siliciclastic 50 2... 

Brisset, F. (2000). Fluid Regime in the Kombolgie Sandstone Uranium Deposits, Northern Territory,... 

Lignite. Deposits generally classified as unconventional uranium resources occur in lignite and in clay or sandstone immediately adjacent to lignite. Examples are uraniferous deposits in the Serres Basin, Greece, North and South Dakota in the United States, and Melovoe in the CIS (17) (see... 

Domestic. Estimates of U.S. uranium resources for reasonably assured resources, estimated additional resources, and speculative resources at costs of 80, 130, and 260/kg of uranium are given in Table 1 (18). These estimates include only conventional uranium resources, which principally include sandstone deposits of the Colorado Plateaus, the Wyoming basins, and the Gulf Coastal Plain of Texas. Marine phosphorite deposits in central Elorida, the western United States, and other areas contain low grade uranium having 30—150 ppm U that can be recovered as a by-product from wet-process phosphoric acid. Because of relatively low uranium prices, on the order of 20.67/kg U (19), in situ leach and by-product plants accounted for 76% of total uranium production in 1992 (20). 

The camotite and roscoeHte ores in the sandstones of the Colorado Plateau have been important sources of vanadium as well as of uranium. 

By far the most important ores of iron come from Precambrian banded iron formations (BIF), which are essentially chemical sediments of alternating siliceous and iron-rich bands. The most notable occurrences are those at Hamersley in Australia, Lake Superior in USA and Canada, Transvaal in South Africa, and Bihar and Karnataka in India. The important manganese deposits of the world are associated with sedimentary deposits the manganese nodules on the ocean floor are also chemically precipitated from solutions. Phosphorites, the main source of phosphates, are special types of sedimentary deposits formed under marine conditions. Bedded iron sulfide deposits are formed by sulfate reducing bacteria in sedimentary environments. Similarly uranium-vanadium in sandstone-type uranium deposits and stratiform lead and zinc concentrations associated with carbonate rocks owe their origin to syngenetic chemical precipitation. 

Sandstone The tertiary, Jurassic and Triassic sandstones of the western Cordillera of the United States account for most of the uranium production in that country. Cretaceous and Permian sandstones are important host rocks in Argentina. Other important deposits are found in carboniferous deltaic sandstones in Niger in Permian Lacustrine siltstones in France and in Permian sandstones of the Alpine region. The deposits in Precambrian marginal marine sandstones in Gabon have also been classified as sandstone deposits. 

More than 30 years ago it became apparent that sandstones of the Athabasca Basin in Saskatchewan are host to significant deposits of uranium. Previous work elsewhere, primarily in the Colorado Plateau (Cannon 1964) and the former Soviet Union (Kovalevsky 1972), had shown that plants are capable of accumulating high concentrations of U. Surveys near the eastern margin of the Athabasca Group revealed an area of... 

Lithium isotopes do not fractionate as a result of redox reactions, but Li is preferentially partitioned into the fluid phase, whereas Li prefers sites in alteration minerals such as micas. The Li/ Li ratios of mica and chlorite in alteration zones around uranium deposits are higher and decrease to lower values with distance from the ore relative to background mica in the Athabasca Group sandstones. In barren areas, high ratios are rare and background ratios are dominant. When used together, the isotopic composition of uranium and lithium can be utilized to refine both the genesis of uranium deposits and as exploration tools. 

U/ U ratios in sandstone-type uranium ores are greater than magmatic uranium ores by 1 %o, but no explanation for this difference was proposed other than a reflection of different redox conditions. 

The U/ U ratios of uranium minerals from volcanic-, metasomatic-, unconformity- and sandstone-related uranium showings and deposits worldwide measured by multi-collector ICP-MS indicate a total variation in values of... 

Unconformity-type uranium deposits, as well as sandstone-hosted deposits, should be zoned in their 238y 5y pg jgg gg g result of two processes. In the first process, the 238y 235y... 

Fig. 2. General alteration and geologic features of basement- and sandstone-hosted uranium deposits showing distributions in U and Li isotope ratios.

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