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《地质学报(英文版)》 2016-02
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Diamonds and Other Exotic Minerals Recovered from Peridotites of the Dangqiong Ophiolite, Western Yarlung-Zangbo Suture Zone, Tibet

XIONG Fahui;YANG Jingsui;ROBINSON Paul T.;XU Xiangzhen;BA Dengzhu;LI Yuan;ZHANG Zhongming;RONG He;CARMA, State Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy of Geological Sciences;  
Various combinations of diamond, moissanite, zircon, quartz, corundum, rutile, titanite, almandine garnet, kyanite, and andalusite have been recovered from the Dangqiong peridotites. More than 80 grains of diamond have been recovered, most of which are pale yellow to reddish-orange to colorless. The grains are all 100-200 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). Integration of the mineralogical, petrological and geochemical data for the Dongqiong peridotites suggests a multi-stage formation for this body and similar ophiolites in the Yarlung-Zangbo suture zone. Chromian spinel grains and perhaps small bodies of chromitite crystallized at various depths in the upper mantle, and encapsulated the UHP, highly reduced and crustal minerals. Some oceanic crustal slabs containing the chromian spinel and their inclusion were later trapped in suprasubduction zones(SSZ), where they were modified by island arc tholeiitic and boninitic magmas, thus changing the chromian spinel compositions and depositing chromitite ores in melt channels.
【Fund】: funded by grants from Sinoprobe-05-02 from the Ministry of Science and Technology of China the NSF China(Nos.41502062 40930313 40921001 41202036);; the China Geological Survey(Nos.12120115027201 12120114061801 2014DFR2127C);; from the Institute of Geology Chinese Academy of Geological Sciences(J1526)
【CateGory Index】: P619.241
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