The Polar Urals region of northern Russia is well known for large chromium （Cr）-bearing massifs with major chromite orebodies, including the Centralnoye I deposit in the Ray-Iz ultramafic massif of the Ural ophiolit...The Polar Urals region of northern Russia is well known for large chromium （Cr）-bearing massifs with major chromite orebodies, including the Centralnoye I deposit in the Ray-Iz ultramafic massif of the Ural ophiolite belt. New data on platinum （Pt）-group elements （PGE）, geochemistry and mineralogy of the host dunite shows that the deposit has anomalous iridium （Ir） values. These values indicate the predominance of ruthenium--osmium--iridium （Ru--Os--Ir）-bearing phases among the platinum-group mineral （PGM） assemblage that is typical of mantle-hosted chromite ores. Low Pt values in chromites and increased Pt values in host dunites might reflect the presence of cumulus PGM grains. The most abundant PGM found in the chromite is erlichmanite （up to 15 μm）. Less common are cuproiridsite （up to 5 μm）, irarsite （up to 4--5 μm）, and laurite （up to 4 μm）. The predominant sulfide is heazlewoodite, in intergrowth with Ni--Fe alloys, sporadically with pentlandite, and rarely with pure nickel. Based on the average PGE values and esti- mated Cr-ore resources, the Centralnoye I deposit can be considered as an important resource of PGE.展开更多
As is well known, platinum-group elements (PGEs) has long been mainly obtained as a byproduct fromsome magmatic deposits of Cu-Ni. The common notion that the platinum-group elements are chemically inert and immobile u...As is well known, platinum-group elements (PGEs) has long been mainly obtained as a byproduct fromsome magmatic deposits of Cu-Ni. The common notion that the platinum-group elements are chemically inert and immobile under most geological conditions. However, a hydrothermal origin at low temperature was recognized for some unusual platinum-group elements occurrences in the unconformity-related uranium deposits in Australia. The possibility of hydrothermal transport of platinum-group elements hasrecently received considerable attention This note introduces the preliminary investigations of platinum-group elements in some Carlin-typegold deposits, southwestern China. 1 Geological展开更多
文摘The Polar Urals region of northern Russia is well known for large chromium （Cr）-bearing massifs with major chromite orebodies, including the Centralnoye I deposit in the Ray-Iz ultramafic massif of the Ural ophiolite belt. New data on platinum （Pt）-group elements （PGE）, geochemistry and mineralogy of the host dunite shows that the deposit has anomalous iridium （Ir） values. These values indicate the predominance of ruthenium--osmium--iridium （Ru--Os--Ir）-bearing phases among the platinum-group mineral （PGM） assemblage that is typical of mantle-hosted chromite ores. Low Pt values in chromites and increased Pt values in host dunites might reflect the presence of cumulus PGM grains. The most abundant PGM found in the chromite is erlichmanite （up to 15 μm）. Less common are cuproiridsite （up to 5 μm）, irarsite （up to 4--5 μm）, and laurite （up to 4 μm）. The predominant sulfide is heazlewoodite, in intergrowth with Ni--Fe alloys, sporadically with pentlandite, and rarely with pure nickel. Based on the average PGE values and esti- mated Cr-ore resources, the Centralnoye I deposit can be considered as an important resource of PGE.
文摘As is well known, platinum-group elements (PGEs) has long been mainly obtained as a byproduct fromsome magmatic deposits of Cu-Ni. The common notion that the platinum-group elements are chemically inert and immobile under most geological conditions. However, a hydrothermal origin at low temperature was recognized for some unusual platinum-group elements occurrences in the unconformity-related uranium deposits in Australia. The possibility of hydrothermal transport of platinum-group elements hasrecently received considerable attention This note introduces the preliminary investigations of platinum-group elements in some Carlin-typegold deposits, southwestern China. 1 Geological
