- 著者
- ABBOU-KEBIR Khadidja ARAI Shoji HASSAN AHMED Ahmed CEULENEER Georges
- 出版者
- 一般社団法人 日本鉱物科学会
- 雑誌
- Journal of mineralogical and petrological sciences (ISSN:13456296)
- 巻号頁・発行日
- vol.106, no.5, pp.235-245, 2011-10-01
- 参考文献数
- 45
- 被引用文献数
- 3
Enigmatic dunitic veins and veinlets crosscutting a podiform chromitite ore body discovered in Wadi Rajmi, northern Oman ophiolite, display a peculiar characteristic of being almost or completely spinel-free. Olivines show an evolution trend from the spinel-free dunites (Fo<sub>93-94</sub> and 0.4 wt% NiO) to the spinel-bearing dunites (Fo<sub>91-93</sub> and 0.2-0.3 wt% NiO). The Cr/(Cr + Al) of chromian spinel grains increases from 0.6 to 0.8, accompanied by a slight increase in Fe<sup>3+</sup> ratio, and the Fo content of olivine decreases in the spinel-bearing dunites. A high-Mg magma, initially undersaturated with chromian spinel, precipitated the spinel-free dunites. Once the spinel saturation of the melt was attained by fractionation, the spinel-bearing dunites precipitated. The initial magma was possibly komatiitic in nature, which was produced at an early stage of detachment of the oceanic lithosphere that formed the Oman ophiolite.
- 著者
- Arai Shoji Tamura Akihiro Ishimaru Satoko Kadoshima Kazuyuki Lee Yong-Il Hisada Ken-ichiro
- 出版者
- Blackwell Publishing
- 雑誌
- Island Arc (ISSN:10384871)
- 巻号頁・発行日
- vol.17, no.4, pp.485-501, 2008-01-01
- 被引用文献数
- 14
金沢大学理工研究域自然システム学系