Metasomatic uranium deposits

Contact-metasomatic uranium deposits contain only a few thousand tons of the Western world s reasonably assured 30 uranium resources. Grades range up to about 0.15% UsOs, but associated metals, such as REE, tend to make them more economic. 

Because of the high temperatures involved in magmatic- and metasomatic-related uranium deposits, variations in their 238y 23Sy pg jgg should be minimal, unless later alteration has resulted in mobilization of uranium. The calcrete deposits measured so far (Fig. 1) are known to have uranium derived from a near-by igneous source, and they have... 

Vein-like deposits were described as uranium deposits of uncertain genesis by Mathews etal Except for a small number of these deposits in sedimentary rocks, the group is subdivided into unconformity-related deposits and deposits of metamorphic rocks. In a more genetic classification of the major (Proterozoic) vein-like deposits of the world, Dahlkamp and Adams deciphered the relationship of diagcncsis, metamorphism, metasomatism and weathering on uranium concentrations in various host rocks. The result is a logical genetic explanation for the spectrum of vein-like deposits observed today. 

Mary Kathleen deposit, Queensland, Australia The Mary Kathleen uranium deposit is in metamorphosed and metasomatized nearshore clastic and carbonate sediments of the lower to middle Corella Formation in northeastern Queensland, Australia. The uppermost unit of the Corella is a breccia-conglomerate formed as a cobble beach. This unit hosted most of the ore at Mary Kathleen. 

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... 

Alteration at Michelin is dominated by intense soda metasomatism and potash depletion, coupled with locally intense hematization much of the mineralization consists of fine-grained uraninite within sodium-rich silicates such as aegirine and arfvedsonite. The recently discovered Jacques Lake deposit, which is an important resource in its own right (about 17 million pounds UsOs), has many similarities to Michelin, although its metavolcanic host rocks are compositionally distinct. The age of the uranium mineralization in these deposits is... 

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