Yangshan A-Type Granites in the Lower Yangtze River Belt Formed by Ridge Subduction:Radiogenic Ca and Nd Isotopic Constraints  

作　　者：Jianghao Bai Mingxing Ling Xiaoyong Yang Fang Liu Huangling Gu Zebin Luo Xiaoyan Jiang Zhaofeng Zhang 

机构地区：[1]State Key Laboratory of Isotope Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China [2]CAS Center for Excellence in Deep Earth Science,Guangzhou 510640,China [3]State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China [4]Key Laboratory of Crust-Mantle Materials and Environments,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [5]International Research Center for Planetary Science,College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China [6]School of City and Environment,Hunan University of Technology,Zhuzhou 412007,China [7]State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China [8]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Earth Science》2022年第3期581-590,共10页地球科学学刊（英文版）

基　　金：the State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang(No.2020Z03);the National Key R&D Program of China(Nos.2016YFC0600408,2019YFA0708400);the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB41020102)。

摘　　要：The Early Cretaceous aluminous A-type granites in the Lower Yangtze River belt(LYRB)can provide important insights into the Mesozoic magmatism in eastern China,but their origin remains highly controversial.In this study,radiogenic Ca-Nd isotopic analysis was performed for syenite porphyry and alkali-feldspar granite porphyry of the Yangshan pluton,a typical aluminous A-type granitic intrusion in the LYRB,to constrain its source and geodynamic setting.The results show thatε_(Ca)(126 Ma),ε_(Nd)(126 Ma)and K/Ca_(source) of the syenite porphyry range from-0.24 to+0.96,-7.2 to-6.0,and 0.31 to 1.26,respectively.The corresponding values for the alkali-feldspar granite porphyry range from 0.26 to 0.84,-8.0 to-6.1,and 0.79 to 1.08,respectively.Binary mixing modeling indicates that they were originated from the same sources with different proportion,namely,a mixing of 50%to 75%Neoproterozoic crust and 50%to 25%asthenospheric mantle.Together with previous works,we propose that the Early Cretaceous subduction of the ridge between the Pacific and Izanagi plates was responsible for the formation of the aluminous A-type granites in the LYRB.

关 键 词：Lower Yangtze River belt(LYRB) aluminous A-type granite Yangshan pluton radiogenic Ca-Nd isotopes ridge subduction GEOCHEMISTRY 

分 类 号：P597[天文地球—地球化学] P588.121[天文地球—地质学]