Serpentinite as a tracer for tectonic setting and mantle metasomatism of ophiolites: A case study of the Aoyougou ophiolite in the Qilian Orogenic Belt, NW China

doi:10.1016/j.gr.2021.12.006

GIG OpenIR

	Zhao, Jing 1; Long, Xiaoping 2; Li, Jie 3; Zhao, Bingshuang 2; Gao, Yilin 2; Zuo, Rui 2
	Serpentinite as a tracer for tectonic setting and mantle metasomatism of ophiolites: A case study of the Aoyougou ophiolite in the Qilian Orogenic Belt, NW China
刊名	GONDWANA RESEARCH
ISSN号	1342-937X
	2022-05-01
卷号	105 页码:1-11
DOI	10.1016/j.gr.2021.12.006
语种	英语
WOS研究方向	Geology
摘要	Serpentinites, particularly those transformed from mantle peridotites, are potential tracers for the petrogenesis and tectonic geodynamics of peridotitic protoliths and certain mantle processes (e.g., fluid/melt metasomatism). This study presents new petrographic observations, mineral chemistry, geochemistry, and Re-Os isotopic compositions of the serpentinites from the Aoyougou ophiolite, the most problematic ophiolite in the Qilian Orogenic Belt, NW China. Our data indicates that the protoliths are melting residues of oceanic lithospheric mantle in a forearc setting. The high Mg-# values (90.49-93.06) of serpentinites confirm their refractory nature, which reflects multiple episodes of partial melting and melt extraction (13.86-18.90%). Moreover, the geochemical fingerprints (e.g., U-shaped rare earth element chondrite-normalized patterns, enrichments of fluid-mobile elements, positive Eu anomalies, extremely high Re-187/Os-188 ratios, high Re abundances) and the "future" model ages (T-MA) of most of the serpentinites show that they had undergone intensive melt/fluid metasomatism. Metasomatism was probably triggered by the input of slab-derived melts/fluids in the forearc setting, which resulted in the introduction of a high abundance of Re. Moreover, the Re-Os isotopic ages record a two-stage evolutionary history of mantle residues that included Precambrian melt extraction and late-Cambrian Re input by mantle metasomatism. Combined with the geological context, an intra-oceanic subduction model was proposed to interpret the origin and evolution of the ophiolite. As a result of the intra-oceanic subduction of the North Qilian Ocean, the oceanic crust of the ophiolite was generated by decompressive melting of the previously depleted forearc mantle. (C) 2021 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
关键词	Qilian Orogenic Belt Re-Os isotopes Serpentinite Mantle metasomatism Intra-oceanic subduction
WOS记录号	WOS:000752799600001
收录类别	SCI
引用统计
文献类型	期刊论文
条目标识符	http://ir.gig.ac.cn/handle/344008/66410
通讯作者	Long, Xiaoping
作者单位	1.Chengdu Univ Technol, Coll Earth Sci, Dept Geochem, Chengdu 610059, Peoples R China 2.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China 3.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Jing,Long, Xiaoping,Li, Jie,et al. Serpentinite as a tracer for tectonic setting and mantle metasomatism of ophiolites: A case study of the Aoyougou ophiolite in the Qilian Orogenic Belt, NW China[J]. GONDWANA RESEARCH,2022,105:1-11.
APA	Zhao, Jing,Long, Xiaoping,Li, Jie,Zhao, Bingshuang,Gao, Yilin,&Zuo, Rui.(2022).Serpentinite as a tracer for tectonic setting and mantle metasomatism of ophiolites: A case study of the Aoyougou ophiolite in the Qilian Orogenic Belt, NW China.GONDWANA RESEARCH,105,1-11.
MLA	Zhao, Jing,et al."Serpentinite as a tracer for tectonic setting and mantle metasomatism of ophiolites: A case study of the Aoyougou ophiolite in the Qilian Orogenic Belt, NW China".GONDWANA RESEARCH 105(2022):1-11.