Mineralogical features of uranium ores, large and superlarge deposits of Russia and adjacent countries

Abstract

The concentration of uranium took place under various ore forming processes (supergene, deep-seated hypergene, hydrothermal) and gave rise to a large number of mineral associations. The author, following the work by Chernikov, Pekov and Minina (1997) distinguishes, on the territory of Russia and adjacent countries, twelve mineralogical types, and several subtypes of uranium ores. Some of these types of ore associations, for instance the beta-uranophane-zeolite, gold-brannerite, molybdenite-brannerite, are not known in other parts of the world. The gold-brannerite, molybdenite-brannerite, pitch-blende-molybdenite ores made up significant and giant deposits. The author explains some physico-chemical conditions in the deep-seated hypergene zone and their role in the formation of large deposits. Also, typomorphic features of ore-forming uranium minerals and associations of large and superlarge deposits are explained. In the complex uranium-vanadium ores (V, Pd , Pt, Au, U) a concentration of noble metals has been established in the near-surface and in the deep-seated oxidized zones. The position of these zones, with a high potential in noble metals, is shown on a vertical section of the Srednija Padma deposit in Karelia, Russia (Fig. 6).