THE GALMOENAN MASSIF, KAMCHATKA, RUSSIA: GEOLOGY, PGE MINERALIZATION, APPLIED MINERALOGY AND BENEFICIATION

The Galmoenan massif, a classic example of an Ural-Alaskan-type zoned intrusive body, is a known source for currently mineable placer-type deposits of platinum. The geology, petrography, geochemistry and PGE mineralization of the Galmoenan massif as well as the applied aspects of PGE mineralogy and ore beneficiation are the focus of this paper. It has been established that Pt-Fe alloys are the principal contributors of PGE in all rock types. They are associated with minor amounts of intermetallic compounds belonging to the system Pt-Fe-Cu and with a paragenesis of PGE-bearing sulfides, arsenides and sulfarsenides. The PGM occur in two major associations: 1) accessory, belonging to the platinum mineralogical-geochemical type, and dispersed in fine-grained dunite, pyroxenite and gabbro, and 2) ore, belonging to the iridium-platinum mineralogical-geochemical type, and related to recrystallized coarse-grained dunite and associated chromitites. The southern part of the Galmoenan intrusion contains important platinum mineralization, and holds the greatest potential for the delineation of an economic, medium-size platinum deposit. The applied mineralogy and beneficiation characteristics of this PGE mineralization, which have not previously been investigated for Ural-Alaskan-type intrusions and which refer to a new economic type of ore, metallic platinum-type ore, are presented.