| Diamonds Discovered from High–Cr Podiform Chromitites of Bulqiza, Eastern Mirdita Ophiolite, Albania |
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| 作者姓名： | XIONG Fahui YANG Jingsui ROBINSON Paul T. DILEK Yildirim MILUSHI Ibrahim XU Xiangzhen ZHOU Wen ZHANG Zhongming RONG He |
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| 作者单位： | 1 CARMA, Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy
of Geological Sciences, Beijing 100037, China,1 CARMA, Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy
of Geological Sciences, Beijing 100037, China,1 CARMA, Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy
of Geological Sciences, Beijing 100037, China,2 Department of Geology& Environmental Earth Science 116 Shideler Hall, Miami University Oxford,
45056 OH, USA,3 Institute of Geosciences, Energy, Water and Environment, Polytechnic University of TIRANA, Albania,1 CARMA, Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy
of Geological Sciences, Beijing 100037, China,4 Faculty of Earth Sciences, China University of Geoscience, Wu’han 430074, Hubei, China,1 CARMA, Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy
of Geological Sciences, Beijing 100037, China and 1 CARMA, Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy
of Geological Sciences, Beijing 100037, China |
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| 基金项目： | We thank the China National Research Center for the geochemical analyses. This research was funded by grants from the NSF China (Nos. 41502062, 41672046, 41541017, 41641015), the China Geological Survey (Nos. DD20160023-01, 201511022), National Key Research and Development Project of China (2016YFC0600310), and from the Institute of Geology, Chinese Academy of Geological Sciences (J1526) and IGCP–649. |
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| 摘 要： | Various combinations of diamond, moissanite, zircon, corundum, rutile and titanitehave been recovered from the Bulqiza chromitites. More than 10 grains of diamond have been recovered, most of which are pale yellow to reddish–orange to colorless. The grains are all 100–300 μm in size and mostly anhedral, but with a range of morphologies including elongated, octahedral and subhedral varieties. Their identification was confirmed by a characteristic shift in the Raman spectra between 1325 cm~(-1) and 1333 cm~(-1), mostly at 1331.51 cm~(-1) or 1326.96 cm~(-1). This investigation extends the occurrence of diamond and moissanite to the Bulqiza chromitites in the Eastern Mirdita Ophiolite. Integration of the mineralogical, petrological and geochemical data of the Bulqiza chromitites suggests their multi–stage formation. Magnesiochromite grains and perhaps small bodies of chromitite formed at various depths in the upper mantle, and encapsulated the ultra–high pressure, highly reduced and crustal minerals. Some oceanic crustal slabs containing the magnesiochromite and their inclusion were later trapped in suprasubduction zones, where they were modified by tholeiitic and boninitic arc magmas, thus changing the magnesiochromite compositions and depositing chromitite ores in melt channels.
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| 关 键 词： | Diamond Multi–stage formation Bulqiza chromitite Ophiolite Albania Proto-Tethys |
| 收稿时间： | 2016/10/24 0:00:00 |
| 修稿时间： | 2016/11/8 0:00:00 |
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