The circular Kondyor massif of ultrabasic rocks Ural-Alaskan type is located in the eastern part of the Aldan shield (Khabarovsk Territory). It became famous for its associated rich platinum placer deposit. Along with the placer-forming Pt mineralization associated with isolated chromites in dunites, the massif shows Cu-Pt-Pd mineralization. According to the results presented by Russian Platina LLC and Artel Amur LLC in 2014 and 2019, the latter may be of great commercial importance.
Cu-Pt-Pd mineralization coincides with the development halo of alkaline sodium metasomatites superimposed in the massif center on dunites, ore pyroxenites (“kosvites”) and phlogopite pegmatites. Mineralization was traced to 500m depth. The true thickness of ore intersections reaches 20m, average Pt and Pd contents vary from 1 to 16 ppm, Cu - from 0.5 to 2%. It has been established that the Cu-Pt-Pd mineralization process includes two main stages. The first stage is associated with the kosvite unit formation, breaking through the dunite core of the Kondyor massif. Mother melts of the assemblage were initially enriched in volatile, chalcophylic, and siderophylic elements, including copper and platinoids. Kosvites crystallization went along with fluids isolation, i.e. with the formation of phlogopite and kosvite-phlogopite stockworks and pegmatite bodies and liquation isolation of sulfide melt enriched in copper and platinoids. In the second stage, associated with intrusion of dikes and veins of nephelinesyenites, ascending fluid flows of carbonate-sodium composition were formed in the central part of the massif. Their effect on kosvites led to remobilization of Fe, Cu, Pt, and Pd and rich polymineral mineralization, represented by submicron occurrences of arsenides, bismuthides, tellurides and intermetallides of Pt and Pd with accompanying Ni, Cu, Pb (vinzenite, menshikovite, kotulskite, sobolevskite, skaergardite, isomertieite, zvyagintsevite, sperrylite, sopcheite, etc.)
Sulfide Pt-Pd mineralization occurrences are known in many basic and ultrabasic massifs of Ural-Alaskan type, as well as in some alkaline massifs. Kondyor’s feature is that PGE mineralization is associated with an alkaline process superimposed on the ultrabasic massif rocks.