Lithological-geochemical features of the Malinovskoe uranium deposit (Russia)

The complex study of uranium ores and their host rocks of the Malinovskoe d eposit revealed their specific mineralogical and geochemical peculiarities, which it differentiate them from all known ancient and recent exogenic epi genetic U deposits of the paleovalley type. Main of them represent: (1) int ense repeated metasomatic chloritization and localized sulfide-selenide min eralization and carbonatization; (2) a slight manifestation of ancient grou nd-stratal oxidation; (3) the presence of elements in uranium ores typical both of exogenic deposits (Se, Re, Mo, V) and hydrothermal mineralization ( Pb, As); (4) a distinct prevalence of coffinite and ferroselite in complex U and Se ores, respectively; (5) the significant penetrating ability and im pact of U-bearing solutions; and (6) the presence of fluid inclusions, whic h point to mixing of thermal calcic (Mg, Fe) chloride brines with meteoric waters. These specific mineralogical and geochemical features of the Malino vskoe deposit are mainly determined by intense endogenic processes and sign ificantly influence technological properties of ores.