Platinum-group minerals in metapyroxenite from Jasov, Meliatic Unit, Slovakia.

The platinum-group minerals (PGM) occur in Triassic-Jurassic metapyroxenite from allochtonous serpentinite body near Jasov village, Meliatic Unit, Inner Western Carpathians, eastern Slovakia. The PGM assemblage originated during two genetic stages. The primary magmatic stage 1, formed under very low fO2; it comprises older generation of PGM: laurite (RuS2), erlichmanite? (OsS2), sperrylite (PtAs2), iridium, and osmium. The younger generation of PGM formed during post-magmatic, hydrothermal-metamorphic stage 2, including irarsite [(Ir,Rh)AsS], hollingworthite [(Rh,Ir)AsS], possibly part of sperrylite (PtAs2), temagamite (Pd3HgTe3), vasilite-like mineral [Pd2(S,Te)], and unnamed phases of (Ir,Os)As3, (Pd,Ni)3Sb, and Pd6Ni3Sb2 (?) stoichiometry. Minerals of the magmatic stage were derived from the deep mantle source under highly reductive conditions, and the primary rock was probably transported by a plume to shallower upper mantle depth. The hydrothermal-metamorphic stage originated by partial hydratation and serpentinization of the metapyroxenite under the blueschists facies metamorphism. The Jasov metapyroxenite represents the first reported occurrence of PGM in the Western Carpathians. [ABSTRACT FROM AUTHOR]