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| 1 | Discovery of the boninite series volcanic rocks in the Bangong Lake ophiolite mélange, western Tibet, and its tectonic implications显示文摘The boninite series volcanic rocks, mainly com- posed of basaltic andesite, andesitic lava breccia and andesite porphyrite, were recognized for the first time in the Bangong Lake ophiolite mélange, western Tibet. These rocks have a strong boninitic affinity, with high SiO2 (55.61%—59.23%, weight percent), MgO (6.63%—13.08%, 9.13% on average (weight percent)), Al2O3/TiO2 ratios (36—54), Mg# (0.61— 0.74), Ni (116 ppm on average) and Cr (354 ppm on average), low TiO2 (0.23%—0.39%, weight percent), and strong LILEs enrichment relative to the depleted HFSEs. C1-chondrite normalized (La/Gd)N and (Gd/Yb)N ratios of about 1.70 and 0.83, respectively, produce prominent “U-shaped” nor- malized REE (rare earth element) patterns. Such a close compositional affinity to boninite indicates that these volcanic rocks were formed in a forearc setting produced by the intra-oceanic subduction. | SHIRendeng YANGJingsui XUZhiqin QIXuexiang | 2004 | Chinese Science Bulletin2004，49，12： | 19 |
| 2 | SHRIMP U-Pb zircon dating for Qiashikansayi granodio-rite, the Northern Altyn Tagh Mountains and its geological implications显示文摘The Qiashikansayi granodiorite is foliated resulting in a granodioritic gneiss. Its geochemical features, such as alumina saturation index(A/CNK) of 0.81-0.99, Na2O/K2O values>1, TiO2 contents <1.0%, LREE enrichment with high fractionation factors, weakly negative or no Eu anomalies, and significant Ba and Ti negative anomalies, suggest that it is similar to a typical island arc pluton. The trace elements of the Qiashikansayi granodiorite are plotted in the island arc field in the tectonic setting discrimination diagrams as well. Cathodoluminescence images demonstrated that the zircons have clear rhythmic crystallized zoning, without any remnant core and new crystallized rim, suggesting the zircons be magmatic ones. Their U and Th contents vary in the range of 574-870μg/g, and 279-556 μg/g respectively, with the Th/U ratio in the range of 0.52-0.68. SHRIMP zircon U-Pb dating yielded the 481.5(5.3 Ma age for the intrusion of the granodiorite, which is coeval with the island arc volcanic rocks in the northern Qilian Mountain, and confirms that there is an early Paleozoic island arc in the Hongliugou- Lapeiquan area. | QIXuexiang LIHaibing WUCailai YANGJingsui ZHANGJianxin MENGFancong SHIRendeng CHENSongyong | 2005 | Chinese Science Bulletin2005，50，5： | 19 |
| 3 | Silicon-rutile - an ultra-high pressure (UHP) mineral from an ophiolite显示文摘Silicon(Si)-rutile separated from the Luobusa podiform chromitite in the Yarlung Zangbo ophiolite of southern Tibet is typically about 50 μm×50 μm×200 μm in size and consists mainly of SiO2 and TiO2. The average mineral formula is (Ti0.82Si0.18)O2. Powder X-ray diffraction data show that it is tetragonal in form, and the unit cell dimensions and other parameters are: a=4.591(2), c=2.946(2), v=62.09(5)3, c/a=0.6415, with a molar volume about 5% smaller than rutile (JCPDS, 21-1276). The Si4+ ions in silicon rutile are six-coordinated, and are substituted for Ti4+ in the rutile structural sites. The Si-rutile, along with other associated ultra-high minerals discovered in the chromitite, such as octahedral silicate, silicon-magnesium spinel (Si4+ ions are six-coordinated), diamond, and intergrown of SiO2 and FeO phases, probably originated from the transition zone or the lower mantle, and were brought to shallow levels beneath an oceanic spreading ridge by an upwelling superplume. | YANGJingsui BAIWenji FANGQingson YANBinggang SHINicheng MAZhesheng DAIMingquan XIONGMing | 2003 | Progress in Natural Science:Materials International2003，13，7： | 14 |
| 4 | Zircon U-Pb SHRIMP dating of the Yematan batholith in Dulan, North Qaidam, NW China显示文摘The Yematan batholith crops out over 120 km2 in the North Qaidam ultrahigh pressure (UHP) metamorphic belt. It consists of granodiorite, monzogranite and biotite granite and forms an irregular intrusion into Neoproterozoic gneiss that has undergone Caledonian UHP metamorphism. Zircons from the Yematan granodiorite yield a SHRIMP U-Pb age of 397? Ma. These granitic rocks have geochemi- cal characteristics intermediate between I- and S-type gran- ites, and are post-collisional. We suggest that the Yematan granitic rocks were formed during the last exhumation event of the North Qaidam UHP belt. | WUCailai YANGJingsui JosephL.Wooden SHIRendeng CHENSongyong AndersMeibom ChrisMattinson | 2004 | Chinese Science Bulletin2004，49，16： | 14 |
| 5 | An X-Ray Diffraction Study of an Inclusion in Diamond from the Luobusha Chromite Deposit in Tibet,China显示文摘Diamond was found in podiform chromitites of ophiolite and harzburgite from Luobusha, Tibet. There are silicate inclusions in some diamond grains from this area. In the present work, the CCD (charge coupled detector) technology of X-ray powder diffraction was applied to the study of the inclusion in diamond from the ophiolite of Tibet. Diffraction patterns are obtained even though the inclusion is only 20 μm in crystal size. The results show that the inclusion in diamond consists of talc and clinochrysotile. Therefore, it is clear that the diamond from the ophiolite of Luobusha, Tibet, is natural diamond rather than a synthetic one. | SHINicheng BAIWenji MAZhesheng FANGQingsong XIONGMing YANBinggang DAIMingquan YANGJingsui | 2003 | Acta Geologica Sinica(English Edition)2003，77，3： | 1 |
| 6 | Protolith ofeclogites in the north Qaidam and Altun UHP terrane, NW China:Earlier oceanic crust?显示文摘 | YangJingsui Wu Cailai ZhangJianxin | 2006 | Journal of Asian Earth Sciences2006，28，： | 1 |
| 7 | Petrogenesis and Dating of Two Types of Granite from North Qilian, China显示文摘Two types of granitic intrusives occur in the lower Paleozoic strata in north Qilian. One is the hornblende- bearing granitic body in Jingzichuan, characterized by the REE total of 90×10-6-106×10-6, LREE/HREE ratio of less than 8 (ranging from 6.9 to 7.8) and zircon SHRIMP age of 464 Ma. These intrusives have island-arc affinity. The other is biotite-bearing granitic body in Huangyanghe with the REE total of 214×10-6-250×10-6, LREE/HREE ratio of more than 8 (ranging from 8.2 to 9.7) and zircon LA-ICP-MS age of 383 Ma. They were tectonically intruded in a post-collisional or within-plate environment. | WUCailai SHIRendeng YANGJingsui YANGHongyi JosephL.WOODEN ZHENGQiuguang CHENGShengyong | 2005 | Acta Geologica Sinica(English Edition)2005，79，2： | 0 |
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