中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Petrogenesis of the ca. 820-810 Ma felsic volcanic rocks in the Bikou Group: Implications for the tectonic setting of the western margin of the Yangtze Block

文献类型:期刊论文

作者Wu, Tao6,8; Wang, Xuan-Ce5,6,7; Li, Wu-Xian3; Wilde, Simon A.4; Tian, Liyan1,2
刊名PRECAMBRIAN RESEARCH
出版日期2019-09-01
卷号331期号:1页码:13
ISSN号0301-9268
关键词Neoproterozoic Felsic Volcanic Rocks A-type Granitoids Extensional Setting Bikou Group Yangtze Block
DOI10.1016/j.precamres.2019.105370
英文摘要

The petrogenesis of Neoproterozoic igneous rocks at the northwestern margin of the Yangtze Block and their tectonic setting are controversial. Here we present whole-rock major and trace elements and Nd-Hf isotopic data for felsic volcanic rocks from the Bikou Group. These ca. 820-810 Ma volcanic rocks consist of dacite and rhyolite with SiO2 ranging from 64.4 to 77.0 wt%. Most rocks show decreasing P2O5 with increasing SiO2 and Th and have I-type granite affinities (metaluminous volcanic rocks). However, four rhyolites from the lower part of the Bikou Group show A-type granite affinities (alkaline rhyolites), characterized by high 10,000*Ga/Al and FeOt/(FeOt + MgO) ratios and high (Zr + Nb + Ce + Y) contents. The felsic volcanic rocks commonly have relatively high Zr saturation temperature (up to 960 degrees C) and most of the felsic volcanic rocks have epsilon(Nd) (t) and epsilon(Hf) (t) values lower than the contemporaneous basalts in the Bikou Group, but higher than the basement rocks in the study area. Among them, four alkaline rhyolites have epsilon(Nd) (t) and epsilon(Hf) (t) values higher than the metaluminous volcanic rocks in the lower Bikou Group. We propose that the metaluminous volcanic rocks were likely produced by partial melting of newly underplated basaltic crust, with involvement of different proportions of basement rocks, whereas a two-stage model is proposed for the formation of the alkaline rhyolites, i.e. partial melting of newly underplated basaltic crust forming early granitoids, followed by low pressure partial melting of these granitoids to generate the alkaline rhyolitic magma. Combined with previous studies, the bimodal occurrence of volcanic rocks within the Bikou Group, and the A-type granite affinity of some rhyolites, as well as the presence of ocean island (OIB)-type basalts in the upper part of Bikou Group, suggest an extensional setting. This is consistent with opening of the Kangdian rift basin to the southwest at this time. We thus propose that the ca. 820-810 Ma Bikou bimodal volcanic rocks formed in response to the breakup of the Rodinia supercontinent.

WOS关键词A-type Granites ; Pb Zircon Geochronology ; Large Igneous Province ; Yidun Arc Belt ; South China ; Geochemical Evidence ; Mantle Plume ; Sm-nd ; Neoproterozoic Granitoids ; Compositional Gaps
资助项目Australian Research Council (ARC) Future Fellowship[FT140100826] ; Hundred Talents Program of Shanxi Province, China[310827163412] ; Science Foundation of Chang'an University[310827163412] ; National Natural Science Foundation of China[41702047] ; Knowledge Innovation Program of Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences[Y570031QY1]
WOS研究方向Geology
语种英语
出版者ELSEVIER
WOS记录号WOS:000486103400027
资助机构Australian Research Council (ARC) Future Fellowship ; Hundred Talents Program of Shanxi Province, China ; Science Foundation of Chang'an University ; National Natural Science Foundation of China ; Knowledge Innovation Program of Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences
版本出版稿
源URL[http://ir.idsse.ac.cn/handle/183446/6990]  
专题深海科学研究部_深海地质与地球化学研究室
通讯作者Wang, Xuan-Ce
作者单位1.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266061, Shandong, Peoples R China
2.Chinese Acad Sci, Inst Deep Sea Sci & Engn, Sanya 572000, Peoples R China
3.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Guangdong, Peoples R China
4.Curtin Univ, Inst Geosci Res, Sch Earth & Planetary Sci, GPO Box U1987, Perth, WA 6845, Australia
5.Changan Univ, Sch Earth Sci & Resources, Xian 710054, Shaanxi, Peoples R China
6.Univ Queensland, Radiogen Isotope Facil, Sch Earth & Environm Sci, Brisbane, Qld 4072, Australia
7.Yunnan Univ, Res Ctr Earth Syst Sci, Key Lab Earth Syst Sci, Kunming 650500, Yunnan, Peoples R China
8.Zhejiang Univ, Ocean Coll, 1 Zheda Rd, Zhoushan 316021, Peoples R China
推荐引用方式
GB/T 7714
Wu, Tao,Wang, Xuan-Ce,Li, Wu-Xian,et al. Petrogenesis of the ca. 820-810 Ma felsic volcanic rocks in the Bikou Group: Implications for the tectonic setting of the western margin of the Yangtze Block[J]. PRECAMBRIAN RESEARCH,2019,331(1):13.
APA Wu, Tao,Wang, Xuan-Ce,Li, Wu-Xian,Wilde, Simon A.,&Tian, Liyan.(2019).Petrogenesis of the ca. 820-810 Ma felsic volcanic rocks in the Bikou Group: Implications for the tectonic setting of the western margin of the Yangtze Block.PRECAMBRIAN RESEARCH,331(1),13.
MLA Wu, Tao,et al."Petrogenesis of the ca. 820-810 Ma felsic volcanic rocks in the Bikou Group: Implications for the tectonic setting of the western margin of the Yangtze Block".PRECAMBRIAN RESEARCH 331.1(2019):13.

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来源:深海科学与工程研究所

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