气候变化领域集成服务门户(CCPortal): The Bangong Lake ophiolite (NW Tibet) and its bearing on the tectonic evolution of the Bangong-Nujiang suture zone

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DOI	10.1016/j.jseaes.2007.11.011
	The Bangong Lake ophiolite (NW Tibet) and its bearing on the tectonic evolution of the Bangong-Nujiang suture zone
	Shi, Rendeng; Yang, Jingsui; Xu, Zhiqin; Qi, Xuexiang
通讯作者	Shi, RD (通讯作者)
发表日期	2008
ISSN	1367-9120
EISSN	1878-5786
起始页码	438
结束页码	457
卷号	32 期号:5-6
英文摘要	The Jurassic Bangong Lake ophiolite, NW Tibet, is a key element within the western part of the Bangong-Nujiang suture zone, which marks the boundary between the Lhasa and Qiangtang blocks. It is a tectonic melange consisting of numerous blocks of peridotite, mafic lavas and dikes. The mantle peridotites include both clinopyroxene-bearing and clinopyroxene-free harzburgites. The Cpx-bearing harzburgite contains Al-rich spinel with low Cr#s (20-25), resembling peridotites formed in mid-ocean ridge settings. On the other hand, the Cpx-free harzburgite is highly depleted with Cr-rich spinel (Cr# = 69-73), typical of peridotites formed in subduction zone environments. Mafic rocks include lavas of N-MORB and E-MORB affinity and boninites. The N-MORB rocks consist of pillow lavas and mafic dikes, whereas the E-MORB rocks are brecciated basalts. The boninites have high SiO2 (53.2-57.9 wt%), MgO (6.5-12.5 wt%), Cr (166-752 ppm) and Ni (63-213 ppm) and low TiO2 (0.22-0.37 wt%) and Y (5.34-8.10 ppm), and are characterized by having U-shaped, chondrite-normalized REE patterns. The N-MORB and E-MORB lavas probably formed by different degrees of partial melting of primitive mantle, whereas the boninites reflect partial melting of depleted peridotite in a suprasubduction zone environment. The geochemistry of the ophiolite suggests that it is a fragment of oceanic lithosphere formed originally at a mid-ocean ridge (MOR) and then trapped above an intraoceanic subduction zone (SSZ), where the mantle peridotites were modified by boninitic melts. The Bangong-Nujiang suture zone is believed to mark the boundary between two blocks within Gondwanaland rather than to separate Gondwanaland from Eurasia. (C) 2007 Elsevier Ltd. All rights reserved.
关键词	DONQIAO OPHIOLITE LUOBUSA OPHIOLITE CHROMIAN SPINEL CONSTRAINTS PERIDOTITES MANTLE LHASA ROCKS
英文关键词	Jurassic ophiolite; MOR; SSZ; Bangong Lake; Tibet
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000256265700011
来源期刊	JOURNAL OF ASIAN EARTH SCIENCES
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/257589
推荐引用方式 GB/T 7714	Shi, Rendeng,Yang, Jingsui,Xu, Zhiqin,et al. The Bangong Lake ophiolite (NW Tibet) and its bearing on the tectonic evolution of the Bangong-Nujiang suture zone[J]. 中国科学院青藏高原研究所,2008,32(5-6).
APA	Shi, Rendeng,Yang, Jingsui,Xu, Zhiqin,&Qi, Xuexiang.(2008).The Bangong Lake ophiolite (NW Tibet) and its bearing on the tectonic evolution of the Bangong-Nujiang suture zone.JOURNAL OF ASIAN EARTH SCIENCES,32(5-6).
MLA	Shi, Rendeng,et al."The Bangong Lake ophiolite (NW Tibet) and its bearing on the tectonic evolution of the Bangong-Nujiang suture zone".JOURNAL OF ASIAN EARTH SCIENCES 32.5-6(2008).