Possible platinum-group element (PGE) oxides in the PGE-mineralized chromitite from the Northern Oman Ophiolite.

• AHMED Ahmed H.

  Central Metallurgical Research and Development Institute

• ARAI Shoji

  Department of Earth Sciences, Kanazawa University

• KADOSHIMA Kazuyuki

  Department of Earth Sciences, Kanazawa University

抄録

A number of platinum-group mineral (PGM) grains with characteristic optical and geochemical properties are found in the recently discovered PGE-mineralized chromitite at Wadi Hilti in the deeper mantle section of the northern Oman ophiolite. They usually occur as polygonal inclusions within fresh chromian spinel. They have exclusively Ru-Os-Ir compositions with low totals on conventional microprobe analysis and show the same Ru-Os-Ir ratios as Os-rich laurite, (Ru, Os, Ir)S₂, commonly found in the chromitite. Qualitative and quantitative analyses show that oxygen is one of major constituents of these PGM grains, and they are Ru-Os-Ir oxides. They are characteristically lower in Fe-Ni contents than Ru-Os-Ir oxides ever reported. The characteristic radial-fibrous textures as well as a hollow space around the polygons possibly mean their secondary origin with significant volume reduction. The similarity of element ratios and mode of occurrence between the PGE oxides and laurite indicates that the former have been produced by desulfurization/oxidation of the latter. Formation of the PGE oxides from Oman has been performed with an increase of Eh at a very early stage of serpentinization.

収録刊行物

• Journal of Mineralogical and Petrological Sciences

  Journal of Mineralogical and Petrological Sciences 97 (4), 190-198, 2002

  一般社団法人　日本鉱物科学会

キーワード

• Geology
• Geophysics

詳細情報

• CRID: 1390282681523459712
• NII論文ID: 130000254868
• DOI: 10.2465/jmps.97.190
• ISSN: 13493825
• ISSN: 13456296
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可