Platinum Assemblage of Matysken River (Koryak Highlands, Russia): Key Properties and Relation with Bedrock Source

Abstract

In this work, we present our first data on the spatial distribution of platinum group elements (PGE) in the minerals of the Matysken massif of Uralian-Alaskan type (Koryak Highlands). The platinum assemblage of the massif is represented by Ir-rich isoferroplatinum rimmed with secondary tetragonal minerals (tulameenite and tetraferroplatinum), native Os and Ir inclusions, minerals of laurite RuS2—erlichmanite OsS2 series. Both primary Pt–Fe and Os–Ir–Ru alloys of central parts of the massif dunite core are enriched in Ir relative to the samples from its outermost parts. The reasons for such distribution remain unclear. However, it corresponds with Nekrasov’s model, which describes the peculiarities of the composition of PGE minerals in different parts of zonal Uralian-Alaskan type massifs.