中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
The syncollisional granitoid magmatism and continental crust growth in the West Kunlun Orogen, China - Evidence from geochronology and geochemistry of the Arkarz pluton

文献类型:期刊论文

作者Zhang, Yu1; Niu, Yaoling2,3,4; Hu, Yan2; Liu, Jinju1; Ye, Lei1; Kong, Juanjuan2; Duan, Meng4
刊名LITHOS
出版日期2016-02-15
卷号245页码:191-204
关键词West Kunlun orogenic belt Syncollisional granitoids Arkarz pluton Mafic magmatic enclave Mazha-Kangxiwa suture Continental crust growth
英文摘要The West Kunlun orogenic belt (WKOB) at the northwest margin of the Greater Tibetan Plateau records seafloor subduction, ocean basin closing and continental collision with abundant syncollisional granitoids in response to the evolution of the Proto- and Paleo-Tethys Oceans from the early-Paleozoic to the Triassic. Here we present a combined study of detailed zircon U-Pb geochronology, whole-rock major and trace elements and Sr-Nd-Hf isotopic geochemistry on the syncollisional Arkarz (AKAZ) pluton with mafic magmatic enclaves (MMEs) exposed north of the Mazha-Kangxiwa suture (MKS) zone. The granitoid host rocks and MMEs of the AKAZ pluton give the same late Triassic age of similar to 225 Ma. The granitoid host rocks are metaluminous granodiorite and monzogranite. They have initial Sr-87/Sr-86 of 0.70818 to 0.70930, epsilon(Nd)(225 Ma) = -4.61 to -3.91 and epsilon(Nd)(225 Ma) = -3.01 to 0.74. The MMEs are more mafic than the host with varying SiO2 (51.00-63.24 wt.%) and relatively low K2O (1.24-3.02 wt.%), but have similar Sr-Nd-Hf isotope compositions to the host ((Sr-87/Sr-86)(i) = 0.70830-0.70955, epsilon(Nd)(225 Ma) = -4.88 to -4.29, epsilon(Hf)(225 Ma) = -2.57 to 0.25). Both the host and MMEs have rare earth element (REE) and trace element patterns resembling those of bulk continental crust (BCC). The MMEs most likely represent cumulate formed from common magmas parental to the granitoid host. The granitoid magmatism is best explained as resulting from melting of amphibolite of MORB protolith during continental collision, which produces andesitic melts with a remarkable compositional similarity to the BCC and the inherited mantle-like isotopic compositions. Simple isotopic mixing calculations suggest that similar to 80% ocean crust and similar to 20% continental materials contribute to the source of the AKAZ pluton. Thus, the hypothesis "continental collision zones as primary sites for net continental crust growth" is applicable in the WKOB as shown by studies in southern Tibet, East Kunlun and Qilian orogens. In addition, we also propose a new view for the tectonic evolution of the Paleo-Tethys Ocean in geological regions recorded and represented by the MKS. (C) 2015 Elsevier B.V. All rights reserved.
收录类别SCI
语种英语
WOS记录号WOS:000371945200015
源URL[http://ir.qdio.ac.cn/handle/337002/126202]  
专题海洋研究所_海洋地质与环境重点实验室
作者单位1.Lanzhou Univ, Sch Earth Sci, 222 South Tianshui Rd, Lanzhou 730000, Peoples R China
2.Chinese Acad Sci, Inst Oceanol, 7 Nanhai Rd, Qingdao 266071, Peoples R China
3.Univ Durham, Dept Earth Sci, Durham DH1 3LE, England
4.China Univ Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China
推荐引用方式
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Zhang, Yu,Niu, Yaoling,Hu, Yan,et al. The syncollisional granitoid magmatism and continental crust growth in the West Kunlun Orogen, China - Evidence from geochronology and geochemistry of the Arkarz pluton[J]. LITHOS,2016,245:191-204.
APA Zhang, Yu.,Niu, Yaoling.,Hu, Yan.,Liu, Jinju.,Ye, Lei.,...&Duan, Meng.(2016).The syncollisional granitoid magmatism and continental crust growth in the West Kunlun Orogen, China - Evidence from geochronology and geochemistry of the Arkarz pluton.LITHOS,245,191-204.
MLA Zhang, Yu,et al."The syncollisional granitoid magmatism and continental crust growth in the West Kunlun Orogen, China - Evidence from geochronology and geochemistry of the Arkarz pluton".LITHOS 245(2016):191-204.

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来源:海洋研究所

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