X-ray diffraction investigation of native Si-Fe alloy minerals from Luobusha, Tibet

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• 作者：Guowu Li (1)
  Nicheng Shi (1)
  Ming Xiong (1)
  Zhesheng Ma (1)
  Wenji Bai (2)
  Qingsong Fang (2)
  
• 关键词：native Si ; Fe alloy mineral ; X ; ray diffraction ; crystal structure ; mantle mineral ; Tibet
• 刊名：Frontiers of Earth Science
• 出版年：2007
• 出版时间：February 2007
• 年：2007
• 卷：1
• 期：1
• 页码：21-25
• 全文大小：380KB
• 参考文献：1. Bai W J, Yang J S, Fang Q S, et al (2004a). Chemical composition of alloy from podifrom chromitites in the Luobusha ophiolite, Tibet. Acta Geologica Sinica, 78(5): 676-82 (in Chinese with English abstract)
  2. Bai W J, Robinson P T, Fang Q S, et al (2004b). The PGE and base-metal alloys in the podiform chromitites of the Luobusha ophiolite, southern Tibet. Acta Geoscientifica Sinica, 25(4): 385-96 (in Chinese with English abstract)
  3. Bai W J, Yang J S, Tao S F, et al (2003a). Si-Fe alloy assemblage in ophiolite of Tibet and their genesis. Acta Petrologica et Mineralogica, 22(3):279-84 (in Chinese with English abstract)
  4. Bai W J, Yang J S, Fang Q S, et al (2003b). An unusual mantle mineral group in ophiolites of Tibet. Geology in China, 30(2): 144-50 (in Chinese with English abstract)
  5. Hu X J (1995). Native fersilicite of China. Acta Petrologica et Mineralogica, 14(1): 71-7 (in Chinese with English abstract)
  6. Knittle E, Jesnloz R (1991). Earth’s core-mantle boundary: Results of experiments at high pressure and temperatures. Science, 25: 1438-443 CrossRef
  7. Li G W, Shi N C, Ma Z S, et al (2005). A new method for powder-like diffractograms of small single crystals using an SMART APEX CCD detector. Acta Mineralogica Sinica, 25(1): 8-2 (in Chinese with English abstract)
  8. Shi N C, Bai W J, Li G W, et al (2005). Crystal chemistry of metallic carbide minerals in the depths of earth. Earth Science Frontiers, 12(1): 29-5 (in Chinese with English abstract)
  
• 作者单位：Guowu Li (1)
  Nicheng Shi (1)
  Ming Xiong (1)
  Zhesheng Ma (1)
  Wenji Bai (2)
  Qingsong Fang (2)
  
  1. Crystal Structure Laboratory, China University of Geosciences, Beijing, 100083, China
  2. Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China
  
• ISSN：2095-0209

文摘

The origin of native Si-Fe alloy mineral is thought to be related with mantle and aerolite. The native Si-Fe alloy minerals from podiform chromites of the Luobusha ophiolite in the Yarlong Zangbo suture zone were examined by a new method for powder-like diffractograms of small single crystals, using an SMART APEX-CCD area-detector X-ray diffractometer. The powder diffraction pattern shows that the minerals are composed of FeSi, FeSi2, β-FeSi2 and native silicon. The association of these minerals suggests that the crystallization order of the mineral may be from early to late FeSi→FeSi2→native silicon, accompanied by gradually increasing deoxidization.