中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Early Neoproterozoic multiple arc-back-arc system formation during subduction-accretion processes between the Yangtze and Cathaysia blocks: New constraints from the supra-subduction zone NE Jiangxi ophiolite (South China)

文献类型:期刊论文

作者Wang, Xin-Shui1,2; Gao, Jun1; Klemd, Reiner3; Jiang, Tuo1,2; Zhai, Qing-Guo4; Xiao, Xu-Chang4; Liang, Xin-Quan5
刊名LITHOS
出版日期2015-11-01
卷号236页码:90-105
关键词Zircon geochronology Supra-subduction zone ophiolite NE Jiangxi ophiolite Back-arc basin rifting Assembly of the South China
DOI10.1016/j.lithos.2015.08.007
文献子类Article
英文摘要The NE Jiangxi ophiolite in the eastern Jiangnan Orogen is a tectonic melange that mainly consists of individual tectonic blocks comprising pyroxenite, gabbro, basalt, diorite, granite and chest in a matrix of serpentinite or tuffaceous greywacke. A combined geochemical and geochronological study of the NE Jiangxi ophiolite was undertaken to constrain the timing and tectonic setting of its formation. The basalts were geochemically subdivided into three groups with different FeOt and TiO2 contents. Group 1 basalts have the lowest FeOt (12.17-13.07 wt.%) and TiO2 (1.48-1.62 wt.%) contents and the lowest Nb/Yb (0.80-0.88) and Th/Nb (0.02-0.03) ratios. Furthermore, they have normal mid-ocean ridge basalt (N-MORB)-like trace element patterns, suggesting derivation from an N-MORB-type mantle source without subduction input. Group 2 Fe-Ti basalts have the highest FeOt (15.52-16.30 wt.%) and TiO2 (3.06-3.23 wt.%) contents, Nb/Yb and Th/Nb ratios from 1.75 to 1.89 and from 0.11 to 0.15, respectively, and trace element patterns similar to those of back-arc basin basalts. The geochemical characteristics suggest that Group 2 basalts were derived from a slightly enriched MORE-type mantle source with a minor subduction contribution. In contrast, Group 3 Fe-Ti basalts have moderate FeOt (12.98-13.40 wt.%) and TiO2 (2.37-2.71 wt.%) contents, and Nb/Yb and Th/Nb ratios from 1.28 to 1.45 and from 0.27 to 0.30, respectively. These basalts further display markedly negative Nb-Ta anomalies and show a geochemical affinity to island-arc basalts (IAB), indicating a slightly enriched MORE-type mantle source that was significantly influenced by subduction-derived fluids and/or melts. SIMS zircon U-Pb dating on gabbros gave ages of 995 +/- 22 Ma and 993 +/- 12 Ma, which are interpreted as the formation age of the NE Jiangxi ophiolite. Positive zircon epsilon(Hf)(t) (+8.8 to +13.8) values for the gabbros and whole-rock epsilon(Nd)(t) (+5.5 to +6.6) values for the basalts indicate that the NE Jiangxi ophiolite originated from an isotopically homogeneous depleted mantle source. The diversity of MORE-to IAB-like basalts and the presence of Fe-Ti basalts favor a formation of the NE Jiangxi ophiolite during the initial rifting phase of an intra-oceanic back-arc basin between an oceanic arc (Huaiyu Terrane) and the continental margin of the Yangtze Block (Puling Terrane) at ca.990 Ma. Both the present and previous studies imply that multiple arc-back-arc systems formed during long-lasting subduction-accretion processes between the Yangtze and Cathaysia blocks during the early Neoproterozoic. (C) 2015 Elsevier B.V. All rights reserved.
WOS关键词HF-ISOTOPE EVIDENCE ; U-PB GEOCHRONOLOGY ; GEOCHEMICAL EVIDENCE ; TECTONIC EVOLUTION ; ZIRCON GEOCHRONOLOGY ; FUCHUAN OPHIOLITE ; OCEANIC BASALTS ; WESTERN MARGIN ; VOLCANIC-ROCKS ; EARTH HISTORY
WOS研究方向Geochemistry & Geophysics ; Mineralogy
语种英语
WOS记录号WOS:000364891500006
资助机构National Natural Science Foundation of China(41172200 ; National Natural Science Foundation of China(41172200 ; China Geological Survey(12120113093900) ; China Geological Survey(12120113093900) ; 40673049) ; 40673049) ; National Natural Science Foundation of China(41172200 ; National Natural Science Foundation of China(41172200 ; China Geological Survey(12120113093900) ; China Geological Survey(12120113093900) ; 40673049) ; 40673049)
源URL[http://ir.iggcas.ac.cn/handle/132A11/62165]  
专题地质与地球物理研究所_中国科学院矿产资源研究重点实验室
作者单位1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China
2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
3.Univ Erlangen Nurnberg, GeoZentrum Nordbayern, D-91054 Erlangen, Germany
4.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China
5.Chinese Acad Sci, Guangzhou Inst Geochem, Guangzhou 510640, Guangdong, Peoples R China
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Wang, Xin-Shui,Gao, Jun,Klemd, Reiner,et al. Early Neoproterozoic multiple arc-back-arc system formation during subduction-accretion processes between the Yangtze and Cathaysia blocks: New constraints from the supra-subduction zone NE Jiangxi ophiolite (South China)[J]. LITHOS,2015,236:90-105.
APA Wang, Xin-Shui.,Gao, Jun.,Klemd, Reiner.,Jiang, Tuo.,Zhai, Qing-Guo.,...&Liang, Xin-Quan.(2015).Early Neoproterozoic multiple arc-back-arc system formation during subduction-accretion processes between the Yangtze and Cathaysia blocks: New constraints from the supra-subduction zone NE Jiangxi ophiolite (South China).LITHOS,236,90-105.
MLA Wang, Xin-Shui,et al."Early Neoproterozoic multiple arc-back-arc system formation during subduction-accretion processes between the Yangtze and Cathaysia blocks: New constraints from the supra-subduction zone NE Jiangxi ophiolite (South China)".LITHOS 236(2015):90-105.

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来源:地质与地球物理研究所

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