中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Origins of two types of serpentinites from the Qinling orogenic belt, central China and associated fluid/melt-rock interactions

文献类型:期刊论文

作者Wu, Kai1,2; Ding, Xing3,4; Ling, Ming-Xing3,4; Sun, Wei-dong4,5,6; Zhang, Li-Peng1,2; Hu, Yong-Bin1; Huang, Rui-Fang1
刊名LITHOS
出版日期2018-03-01
卷号302页码:50-64
关键词Serpentinites Qinling orogenic belt Mianlue ophiolite melange Subduction channel
ISSN号0024-4937
DOI10.1016/j.lithos.2017.12.019
通讯作者Ding, Xing(xding@gig.ac.cn) ; Ling, Ming-Xing(mxling@gig.ac.cn)
英文摘要Serpentinites are important volatile and fluid mobile element repositories in oceanic lithosphere and subduction zones, and thus provide significant constraints on global geochemical cycles and tectonic evolution at convergent margins. In this contribution, two types of serpentinites from the Mianlue suture zone in the Qinling orogenic belt, central China, are identified on the basis of detailed mineralogical and geochemical study. Serpentinites from the Jianchaling region (Group 1) are composed of lizardite/chrysotile + magnesite + magnetite. Most of these serpentinites (Group la), consist of pseudomorphic orthopyroxene and olivine, and are characterized by low Al2O3/SiO2, high MgO/SiO2 and Ir-type PGEs to Pt ratios, suggesting a residual mantle origin. Meanwhile, the U-shape REE pattern and positive Eu, Sr and Ba anomalies of these serpentinites indicate that serpentinization fluids have interacted with gabbroic cumulates at moderately high temperatures or associate with the chlorinity and redox conditions of the fluid. Considering the limited mobility of U in the hydrating fluids for the Group la serpentinites, hydrating fluids for these serpentinites are most likely derived from the dehydrated slab, and have been in equilibrium with subducting sediments. There are also some serpentinites with low-grade metamorphic recrystallization from the Jianchaling region (Group 1b), represented by recrystallized serpentine minerals (antigorite). The trace element compositions of these Group 1b serpentinites suggest that partial dehydration of serpentinites associated with the transformation from lizardite to antigorite in subduction zone is also likely to affect the geochemistry of serpentinites. Serpentinites from the Liangyazi region (Group 2) are composed of antigorite + dolomite + spinel + magnetite. The high Cr number (0.65-0.80) and low Ti concentrations of spinels in Group 2 serpentinites indicate a refractory mantle wedge origin. Fertile major element compositions (e.g., high Al2O3 content and Al2O3/SiO2) and conjoint enrichment in light rare earth elements and high field strength elements, however, suggest melt-rock interactions before serpentinization. Combined with their geochemical affinity to "subducted serpentinites", we conclude that their protoliths (refractory mantle wedge peridotite) experienced melt-rock interactions and then were incorporated into the subduction channel before serpentinization. Studies on these two types of serpentinites indicate that serpentinites from the orogenic belt are most likely characterized by multi-source, multi-stage and multi-genesis, further providing important constraints on subduction channel processes. (C) 2017 Elsevier B.V. All rights reserved.
资助项目Chinese Academy of Sciences[XDB06030101] ; Natural Science Foundation of China[41421062] ; Guangdong Natural Science Funds[2014A030306032] ; Guangdong Natural Science Funds[2015TQ01Z611] ; Youth Innovation Promotion Association CAS[2016315]
WOS研究方向Geochemistry & Geophysics ; Mineralogy
语种英语
WOS记录号WOS:000428497500004
出版者ELSEVIER SCIENCE BV
源URL[http://ir.qdio.ac.cn/handle/337002/158474]  
专题海洋研究所_深海极端环境与生命过程研究中心
通讯作者Ding, Xing; Ling, Ming-Xing
作者单位1.Chinese Acad Sci, Guangzhou Inst Geochem, Key Lab Mineral & Metallogeny, Guangzhou 510640, Guangdong, Peoples R China
2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
3.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China
4.Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
5.Chinese Acad Sci, Inst Oceanog, Ctr Deep Sea Res, Qingdao 266071, Peoples R China
6.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China
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Wu, Kai,Ding, Xing,Ling, Ming-Xing,et al. Origins of two types of serpentinites from the Qinling orogenic belt, central China and associated fluid/melt-rock interactions[J]. LITHOS,2018,302:50-64.
APA Wu, Kai.,Ding, Xing.,Ling, Ming-Xing.,Sun, Wei-dong.,Zhang, Li-Peng.,...&Huang, Rui-Fang.(2018).Origins of two types of serpentinites from the Qinling orogenic belt, central China and associated fluid/melt-rock interactions.LITHOS,302,50-64.
MLA Wu, Kai,et al."Origins of two types of serpentinites from the Qinling orogenic belt, central China and associated fluid/melt-rock interactions".LITHOS 302(2018):50-64.

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来源:海洋研究所

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