Geochronology and geochemistry of Late Carboniferous dykes in the Aqishan-Yamansu belt, eastern Tianshan: Evidence for a post-collisional slab breakoff
文献类型:期刊论文
作者 | Long, Xiaoping2; Wu, Bin2; Sun, Min3; Yuan, Chao1; Xiao, Wenjiao4; Zuo, Rui2 |
刊名 | GEOSCIENCE FRONTIERS
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出版日期 | 2020 |
卷号 | 11期号:1页码:347-362 |
关键词 | Central Asian orogenic belt Eastern Tianshan Adakitic Highly fractionated I-Type granite Slab breakoff |
ISSN号 | 1674-9871 |
DOI | 10.1016/j.gsf.2019.06.003 |
英文摘要 | With aim of providing constraints on the Late Paleozoic tectonic evolution of the southern Central Asian Orogenic Belt (CAOB), an integrated study was conducted on the geochronological and geochemical data for dioritic, granitic and diabase dykes from the Aqishan-Yamansu belt in the eastern Tianshan, NW China. Zircon U-Pb dating indicates that the dioritic and granitic dykes were both emplaced in the Late Carboniferous (similar to 311 Ma and similar to 315 Ma). The dioritic dykes show adakitic characteristics and have high Na2O and positive epsilon(Hf)(t) values (+12 to +17), which suggest an origin from partial melts of a subducted oceanic slab. The granitic dykes have high SiO2 and K2O contents and are characterized by enriched light rare earth elements (LREE) and slightly flat heavy rare earth elements (HREE), with negative Eu and Nb-Ta-Ti anomalies. These dykes are alkali-calcic and show geochemical features of highly fractionated I-type granites. Their positive epsilon(Hf)(t) values (+16 to +17) suggest that they were derived from a juvenile accreted oceanic crustal source. The coeval diabase dykes have low SiO2 and K2O contents but high TiO2, MgO and Mg# (54-59). They are enriched in LREE and show characteristics of enriched mid-ocean ridge basalts (E-MORB). The relatively high Ba/Th, slightly low Th/Ta ratios, and negative Nb-Ta anomalies imply a mantle source metasomatised by slab-derived fluids. Thus, these basic dykes were generated likely by partial melting of the upwelling asthenosphere mantle with a slight influence of slab-derived fluids. Therefore, we suggest that the formation of these Late Carboniferous dykes were triggered by a post-collisional slab breakoff and the Aqishan-Yamansu belt was a continental arc formed by south-dipping subduction of the Kangguer oceanic plate. (C) 2019, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. |
WOS关键词 | ZIRCON U-PB ; PALEOZOIC TECTONIC EVOLUTION ; NW CHINA IMPLICATIONS ; A-TYPE GRANITES ; OROGENIC BELT ; CENTRAL-ASIA ; VOLCANIC-ROCKS ; CONTINENTAL-CRUST ; YILI BLOCK ; GEODYNAMIC EVOLUTION |
资助项目 | National Natural Science Foundation of China[41421002] ; National Natural Science Foundation of China[41603028] ; MOST Special Fund from the State Key Laboratory of Continental Dynamics |
WOS研究方向 | Geology |
语种 | 英语 |
WOS记录号 | WOS:000503182200021 |
出版者 | CHINA UNIV GEOSCIENCES, BEIJING |
资助机构 | National Natural Science Foundation of China ; National Natural Science Foundation of China ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; MOST Special Fund from the State Key Laboratory of Continental Dynamics ; MOST Special Fund from the State Key Laboratory of Continental Dynamics |
源URL | [http://ir.iggcas.ac.cn/handle/132A11/95876] ![]() |
专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
通讯作者 | Long, Xiaoping |
作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Guangdong, Peoples R China 2.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Shaanxi, Peoples R China 3.Univ Hong Kong, Dept Earth Sci, Pokfulam Rd, Hong Kong, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China |
推荐引用方式 GB/T 7714 | Long, Xiaoping,Wu, Bin,Sun, Min,et al. Geochronology and geochemistry of Late Carboniferous dykes in the Aqishan-Yamansu belt, eastern Tianshan: Evidence for a post-collisional slab breakoff[J]. GEOSCIENCE FRONTIERS,2020,11(1):347-362. |
APA | Long, Xiaoping,Wu, Bin,Sun, Min,Yuan, Chao,Xiao, Wenjiao,&Zuo, Rui.(2020).Geochronology and geochemistry of Late Carboniferous dykes in the Aqishan-Yamansu belt, eastern Tianshan: Evidence for a post-collisional slab breakoff.GEOSCIENCE FRONTIERS,11(1),347-362. |
MLA | Long, Xiaoping,et al."Geochronology and geochemistry of Late Carboniferous dykes in the Aqishan-Yamansu belt, eastern Tianshan: Evidence for a post-collisional slab breakoff".GEOSCIENCE FRONTIERS 11.1(2020):347-362. |
入库方式: OAI收割
来源:地质与地球物理研究所
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