Late Mesozoic Wangxiang Composite Granitic Pluton,South China Block:Implications to Magma Emplacement and Evolution from Geochemical Proxies  

作　　者：Quan Ou Jing-Yi Liu Feng Zi Bruna BCarvalho Xiaoping Long Jian-Qing Lai Kun Wang Zi-Qi Jiang Yi-Zhi Liu Zheng-Lin Li Hong-Yun Wang 

机构地区：[1]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,and Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources,Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China [2]State Key Laboratory of Continental Dynamics,Northwest University,Xi'an 710069,China [3]Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Ministry of Education,School of Geosciences and Info-Physics,Central South University,Changsha 410083,China [4]School of Earth Sciences and Spatial Information Engineering,Hunan University of Science and Technology,Xiangtan 411201,China [5]Dipartimento di Geoscienze,Universitàdegli studi di Padova,Via G.Gradenigo 6,Padova 35131,Italy [6]School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China [7]Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration,and College of Earth Sciences,Guilin University of Technology,Guilin 541004,China

出　　处：《Journal of Earth Science》2025年第2期485-507,共23页地球科学学刊(英文版)

基　　金：provided by the National Natural Science Foundation of China(No.41002022);the National Key R&D Program of China(No.2017YFC0602402);the Provincial Natural Science Foundation of Hunan(No.2019JJ50831);the Opening Foundation of State Key Laboratory of Continental Dynamics,Northwest University(No.20LCD08);the Funded by Open Research Fund Programme of the Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education(No.2018YSJS07);Bruna B.Carvalho is thankful to MIUR(Ministero dell’Istruzione,dell’Universitàe della Ricerca)for the award of a grant(No.PNRA18_00103)。

摘　　要：Composite granitic pluton with distinct units is a potential target for identifying its detailed magma evolution.Here,we present zircon U-Pb ages and Hf isotope,whole-rock major and trace element compositions and Nd-Pb isotopes of the Wangxiang composite pluton,South China.New ages obtained show that these rocks were generated in Late Jurassic(ca.156–158 Ma).The rocks are divided into low silica(SiO_(2)<67 wt.%,biotite granodiorites and their dioritic enclaves)and high silica ones(SiO_(2)>71 wt.%,two-mica granites,garnet-bearing muscovite granites and muscovite granites).The high silica rocks are enriched in light rare earth elements(LREEs)relative to heavy REEs(HREEs)((La/Yb)_(N)=15.6–41.9,while the low silica rocks are not(0.7–76.6).All rocks show various negative Ti,Sr,Eu and strong positive Pb anomalies.The low silica rocks have less negative values ofε_(Nd)(t)(-8.79 to-6.99),similar values of~((206)Pb/^(204)Pb)_(i)(18.155–18.346)andε_(Hf)(t)(-9.51 to-3.47,except one-12.84),compared to the high silica rocks(ε_(Nd)(t)=-11.14 to-10.26;^((206)Pb/^(204)Pb)_(i)=17.935–19.093;ε_(Hf)(t)=-12.03 to-7.15,except one-2.41).Data suggest that the parental magma of the studied rocks(represented by enclaves)was produced by partial melting of a garnet-free crustal source.Subsequently those crustal magmas formed the more evolved units through assimilation and fractional crystallization processes,and fluid enrichment during the final magmatic activity.Combining our results with previous multidisciplinary studies,we propose that the key factor to control the evolution of Wangxiang composite pluton is discrete emplacement of crustal magmas by dyking.

关 键 词：composite granitic pluton Late Jurassic assimilation and fractional crystallization fluid influence discrete emplacement South China GEOCHEMISTRY 

分 类 号：P588.2[天文地球—岩石学]