The Weixi High-silica Granitoids in the Central Sanjiang Orogenic Belt,Southwest China:Implications for Growth of the Continental Crust  

作　　者：WANG Qiuyu CHEN Shouming ZHANG Hongrui LI Saisai 

机构地区：[1]SinoProbe Laboratory,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [2]Guangxi Key Laboratory of Hidden Metallic Ore Deposit Exploration,Guilin,Guangxi 541004,China

出　　处：《Acta Geologica Sinica(English Edition)》2024年第3期641-656,共16页地质学报（英文版）

基　　金：financially supported by the State Key Research Development Program of China(Grant No.2022YFF0800903);the National Natural Science Foundation of China(NSFC)(Grant Nos.42261144669 and 42273073)。

摘　　要：High-silica granitoids record the formation and evolution of the continental crust.A new intrusive complex has been recognized among silicic volcanic rocks of the Weixi arc,Southwest China.The intrusions consist of granites,granitic porphyries,and granodiorites.Zircon U-Pb age data indicate that the Weixi granitoids formed at 248-240 Ma and were coeval with silicic volcanic rocks of the Weixi arc.The Weixi granitoids are enriched in Rb,Th,and U,depleted in Ba,Sr,Nb,Ta,and Ti,and have high light/heavy rare earth element ratios and slightly negative Eu anomalies.The Weixi granitoids have negative ε_(Nd)(t)values(-9.8 to-7.8)and negative zircon ε_(Hf)(t)values(-12.02 to-5.11).The geochemical and isotopic features suggest the Weixi granitoids were derived by partial melting of ancient crustal material.The Weixi granitoids and silicic volcanic rocks were derived from the same magma by crystal accumulation and melt extraction,respectively,and they record the formation of a continental arc in the central Sanjiang orogenic belt.

关 键 词：GRANITOIDS GEOCHEMISTRY crystal accumulation continental crust Sanjiang orogen 

分 类 号：P588.121[天文地球—岩石学] P542[天文地球—地质学]