中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Petrogenesis of post-orogenic syenites in the Sulu Orogenic Belt, East China: geochronological, geochemical and Nd-Sr isotopic evidence

文献类型:期刊论文

作者Yang, JH; Chung, SL; Wilde, SA; Wu, FY; Chu, MF; Lo, CH; Fan, HR
刊名CHEMICAL GEOLOGY
出版日期2005-01-03
卷号214期号:1-2页码:99-125
关键词Post-orogenic Magmatism Potassic To ultraPotassic Magmatism Sulu Uhp Belt North China Craton
ISSN号0009-2541
DOI10.1016/j.chemgeo.2004.08.053
文献子类Article
英文摘要The Jiazishan alkaline complex in the eastern Sulu ultrahigh pressure (UHP) metamorphic orogenic belt of eastern China is composed of potassic to ultrapotassic pyroxene syenite, quartz syenite and associated mafic dikes. A SHRIMP zircon Pb-206/U-238 age of 215 +/- 5 Ma was obtained for the quartz syenite and mineral Ar-40/Ar-39 dating gave emplacement ages of 214.4 +/- 0.3 and 214.6 +/- 0.6 Ma for the pyroxene syenite and 200.6 +/- 0.2 Ma for the mafic dike. These dates establish that the Jiazishan Complex was emplaced shortly after the UHP metamorphic event at 240 to 220 Ma due to the continental collision between the North China and Yangtze cratons. The ultrapotassic mafic dikes, with K2O approximate to 4.4-6.4 wt.% and K2O/Na2O approximate to 3.5, have high MgO (8.06-12.44 wt.%), Ni (119-319 ppm) and Cr (477-873 ppm) and moderately low CaO/Al2O3 (similar to0.76) and TiO2 (similar to1.12 wt.%). They also have high Sr (Sr-87/(16)Srsimilar to0.7073), low Nd (epsilon(Nd) = similar to-16.5) isotopic ratios, enriched LILE (Ba/La=66-74), LREE [(La/Yb)(N)=28-33] and depleted HFSE (La/Nb=4-6). It appears that the mafic dikes were derived from a refractory, re-enriched lithospheric mantle source. The syenites have Sr and Nd isotopic compositions similar to the mafic dikes, implying a common origin. Geochemical and isotopic modeling suggests that the pyroxene syenites may have been generated by early fractionation of clinopyroxene and olivine, coupled with minor amounts of crustal contamination, of a mafic magma that had a similar composition to the mafic dikes. Subsequent fractionation of feldspar-dominated assemblages, with minor or no contamination, would result in the quartz syenites. This post-orogenic magmatism, resulting most likely in an extensional setting, provides time constraints on the major geodynamic transition from convergence to extension at the eastern margin of the North China craton. The Jiazishan potassic magmatism and geodynamic transition from convergence to extension can be explained by convective removal of the lower lithospheric mantle. (C) 2004 Elsevier B.V. All rights reserved.
WOS关键词COESITE-BEARING ECLOGITES ; U-PB ZIRCON ; ULTRAHIGH-PRESSURE TERRANE ; QINLING-DABIE OROGEN ; CONTINENTAL-CRUST ; JIAODONG PENINSULA ; NORTHEASTERN JIANGSU ; LITHOSPHERIC MANTLE ; METAMORPHIC ROCKS ; COOLING HISTORY
WOS研究方向Geochemistry & Geophysics
语种英语
WOS记录号WOS:000226223800006
出版者ELSEVIER SCIENCE BV
源URL[http://ir.iggcas.ac.cn/handle/132A11/64876]  
专题中国科学院地质与地球物理研究所
通讯作者Yang, JH
作者单位1.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
2.Natl Taiwan Univ, Dept Geosci, Taipei 106, Taiwan
3.Curtin Univ Technol, Dept Appl Geol, Perth, WA 6001, Australia
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Yang, JH,Chung, SL,Wilde, SA,et al. Petrogenesis of post-orogenic syenites in the Sulu Orogenic Belt, East China: geochronological, geochemical and Nd-Sr isotopic evidence[J]. CHEMICAL GEOLOGY,2005,214(1-2):99-125.
APA Yang, JH.,Chung, SL.,Wilde, SA.,Wu, FY.,Chu, MF.,...&Fan, HR.(2005).Petrogenesis of post-orogenic syenites in the Sulu Orogenic Belt, East China: geochronological, geochemical and Nd-Sr isotopic evidence.CHEMICAL GEOLOGY,214(1-2),99-125.
MLA Yang, JH,et al."Petrogenesis of post-orogenic syenites in the Sulu Orogenic Belt, East China: geochronological, geochemical and Nd-Sr isotopic evidence".CHEMICAL GEOLOGY 214.1-2(2005):99-125.

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来源:地质与地球物理研究所

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