Origin of spinel-free dunites associated with podiform chromitites from northern Oman ophiolite

• Abbou-Kebir Khadidja

  Kanazawa Uni. Sci., Japan

• Arai Shoji

  Kanazawa Uni. Sci., Japan

• Hassan Ahmed Ahmed

  King Abdel Aziz Uni. Sci., Jeddah, Saudi Arabia

抄録

Oman ophiolite, one of the well preserved in the world, offers a panel of geological occurrences among which the podiform chromitites and the dunitic veins or dikes outcropping both at different depths from the Moho transition zone to upper mantle. They are widely assumed to witness melt/rock interactions and a channeling system facilitating melt flux beneath a mid-oceanic ridge, respectively. However, at the present day, none study has mentioned the occurrence of a dunitic network crosscutting a podiform chromitite with emphasizing, moreover, the unusual and remarkable "Cr-spinel poor" or "Cr-spinel free" dunite characteristic. Considering the importance of such a challenging issue, made possible after the discovery of the podiform chromitite recording the latter peculiar phenomenon within the Wadi Rajmi, northern part of Oman ophiolite, we carried out a meticulous field and microscopic observations which allowed us to enunciate two hypotheses: (1) either the melt at the origin of the dunite veins was oversaturated in term of olivine or (2) the mechanical segregation of Cr-spinels from the intruding melt and their addition to the preexisting chromitite.

収録刊行物

• 日本鉱物科学会年会講演要旨集

  日本鉱物科学会年会講演要旨集 2010 (0), 227-227, 2010

  一般社団法人日本鉱物科学会

キーワード

• podiform chromitites
• spinel-free dunites
• oman

詳細情報

• CRID: 1390001205544916992
• NII論文ID: 10026666707
• NII書誌ID: AA12444619
• DOI: 10.14824/jakoka.2010.0.227.0
• 本文言語コード: en
• データソース種別:
  • JaLC
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可