| Evolution of the Mesozoic Granites in the Xiong'ershan-Waifangshan Region,Western Henan Province,China,and Its Tectonic Implications |
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| 作者姓名： | Franco PIRAJNO |
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| 作者单位： | Geological Survey |
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| 摘 要： | Based on the new data of isotopic ages and geochemical analyses, three types of Mesozoic granites have been identified for the Xiong'ershan-Waifangshan region in western Henan Province: high-Ba-SrⅠ-type granite emplaced in the early stage (～160 Ma),Ⅰ-type granite in the middle stage (～130 Ma) and anorogenic A-type granite in the late stage (～115 Ma). Geochemical characteristics of the high-Ba-SrⅠ-type granite suggest that it may have been generated from the thickened lower crust by partial melting with primary residues of amphibole and garnet. Gradual increase of negative Eu anomaly and Sr content variations reflect progressive shallowing of the source regions of these granites from the early to late stage. New 40Ar/39Ar plateau ages of the early-stage Wuzhangshan granite (156.0±1.1 Ma, amphibole) and middle-stage Heyu granite (131.8±0.7 Ma, biotite) are indistinguishable from their SHRIMP U-Pb ages previous published, indicating a rapid uplift and erosion in this region. The representative anorogenic A-type granite, Taishanmiao pluton, was emplaced at～115 Ma. The evolution of the granites in this region reveals a tectonic regime change from post-collisional to anorogenic between～160 Ma and～115 Ma. The genesis of the early- and middle-stageⅠ-type granites could be linked to delamination of subducted lithosphere of the Qiniing orogenic belt, while the late-stage A-type granites represent the onset of extension and the end of orogenic process. In fact, along the Qiniing -Dabie-Sulu belt, the Mesozoic granitoids in western Henan, Dabieshan and Jiaodong regions are comparable on the basis of these temporal evolutionary stages and their initial 87Sr/86Sr ratios, which may suggest a similar geodynamic process related to the collision between the North China and Yangtze cratons.
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Evolution of the Mesozoic Granites in the Xiong'ershan-Waifangshan Region,Western Henan Province,China,and Its Tectonic Implications |
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| Authors: | HAN Yigui ZHANG Shihong Franco PIRAJNO and ZHANG Yuanhou State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China Geological Survey of Western Australia Plain Street East Perth WA Australia The College of Earth Sciences Jilin University Changchun China |
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| Affiliation: | HAN Yigui,ZHANG Shihong,Franco PIRAJNO and ZHANG Yuanhou State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China Geological Survey of Western Australia,100 Plain Street,East Perth,WA 6004,Australia The College of Earth Sciences,Jilin University,Changchun 130061,China |
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| Abstract: | |
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| Keywords: | granite Mesozoic high Ba-Sr 40Ar/39Ar dating post-collision anorogenic western Henan |
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