Geochemistry and mineralogy of platinum-group elements (PGE) in chromites from Centralnoye I, Polar Urals, Russia

详细信息    查看全文

• 作者：Jan  ; Pa&scaron ; ava^a ;   ; ^{jan.pasava@geology.cz} ; Ilja  ; Kn&eacute ; sl^a ; Anna  ; Vymazalová ; ^a ; Ivan  ; Vav?í ; n^a ; Ludmila Ivanovna  ; Gurskaya^b ; Leonid Ruslanovich  ; Kolbantsev^b
• 关键词：Platinum-group elements ; Platinum-group minerals ; Chromite ; Ophiolites ; Centralnoye I deposit ; Polar Urals
• 刊名：Geoscience Frontiers
• 出版年：2011
• 出版时间：January 2011
• 年：2011
• 卷：2
• 期：1
• 页码：81-85
• 全文大小：690 K

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¨Cosmium¨Ciridium (Ru¨COs¨CIr)-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?¦Ìm). Less common are cuproiridsite (up to 5?¦Ìm), irarsite (up to 4??¦Ìm), and laurite (up to 4?¦Ìm). The predominant sulfide is heazlewoodite, in intergrowth with Ni¨CFe alloys, sporadically with pentlandite, and rarely with pure nickel. Based on the average PGE values and estimated Cr-ore resources, the Centralnoye I deposit can be considered as an important resource of PGE.