Mineral types of uranium ores in sodic metasomatites, Ukrainian shield

The uranium deposits in sodic metasomatites of the Ukrainian Shield are dated at about 1800 Ma and were formed during the protoactivization of an ancient protoplatform within various host rocks: Mg-Fe rocks (amphibole gneisses, iron-rich quartzites, and iron ores) in the Krivoi Rog iron basin, and aluminosilicate rocks (amphibole-biotite gneisses, migmatites, and granitoids) in the Kirovograd district. The substrate composition affected the composition of metasomatites, and during a single hydrothermal-metasomatic process aegirinites, magnetite-alkali amphibole and Fe-carbonate metasomatites were formed after the Mg-Fe rocks, whereas alkali amphibole-aegirine albitites originated after the aluminosilicate rocks. A detailed study and mineralogical mapping of the deposits allowed us to distinguish the following six mineral types of ores in sodic metasomatites: uraninite; uraninite-brannerite; nenadkevite; coffinite-pitchblende (uraninite)-brannerite; malacon-apatite; and sulfide-pitchblende. We also compared these ore types and revealed their spatial and temporal relationships. The ores of each type differ in composition and localization conditions and compose significant volumes of individual ore lodes, separate ore lodes, or even separate deposits.