Radvanec M. & Uher P., 2016: Platinum-group minerals in metapyroxenite from Jasov, Meliatic Unit, Slovakia. Acta Geologica Slovaca, 8, 2, 195–201.

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

Martin Radvanec¹ & Pavel Uher²

¹State Geological Institute of Dionýz Štúr, Mlynská dolina 1, 817 04 Bratislava, Slovakia; martin.radvanec@geology.sk
²Department of Mineralogy and Petrology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia; puher@fns.uniba.sk

Abstract

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.

Key words: platinum-group minerals, awaruite, metapyroxenite, serpentinization, Western Carpathians, Meliatic Unit

Manuscript received: 2016-07-01

Revised version accepted: 2016-11-04