Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)

Geochemistry and mineralogy of PGE in chromites from the Centralnoye I deposit, Polar Urals, Russia

 

Jan Pašava, Ilja Knésl, Anna Vymazalová, Ivan Vavřín, Ivanovna Gurskaja, Leonid Kolbancev

Geoscience Research Reports 43, 2010 (GRR for 2009), pages 236–239

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Abstract

The region of the Polar Urals (Russia) is known for occurrences of large Cr-bearing massifs. We present the new data on platinum group elements geochemistry and mineralogy in chromite ores from various orebodies of the Centralnoye I deposit including host dunite. The deposit is located within the Ray-Iz ultramafic massif that belongs to the Ural ophiolite belt. Anomalous IPGE values indicate the predominance of Ir-Os-Ru-bearing phases among the platinum group minerals (PGM) assemblage that is typical of mantle-hosted ophiolitic chromite ores. Low Pt values in chromites and increased Pt values in host dunites could reflect the presence of cumulus PGM grains. The most abundant platinum-group mineral in studied chromite is erlichmanite (up to 15 |m). Less common are cuproiridsite (up to 5 |m), irarsite (up to 4-5 |m) and laurite (up to 4 |m). Predominant sulphide is heazlewoodite, in intergrowth with Ni-Fe alloys, sporadically with pentlandite, and rarely with pure nickel. Considering average PGE values and estimated Cr-ore resources, the Centralnoye I deposit can be considered as an important resource of PGE.