【作者】 龙灵利； 高俊； 熊贤明； 钱青；

【Author】 LONG LingLi,GAO Jun,XIONG XianMing and QIAN Qing 1.Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China 2.Earth Science College,Graduate University of Chinese Academy of Science,Beijing 100039,China

【机构】 中国科学院地质与地球物理研究所矿产资源重点实验室； 中国科学院研究生院；

【摘要】 伊犁-中天山板块南缘比开地区出露的花岗岩和花岗闪长岩具钙碱性大陆弧花岗岩特征,其形成与南天山洋向北的俯冲事件相关。LA-ICP-MS锆石U-Pb年代学研究表明,岩浆活动在479～401Ma间一直发生,其中419～401Ma间岩浆活动强烈,形成大量钙碱性花岗岩组成的中天山南缘陆缘弧。(⁸⁷Sr/⁸⁶Sr)_i=0.711578～0.704729,ε_Nd（t）=-5.01～-2.19,表明花岗岩的形成过程中有地幔物质的加入,而Nd模式年龄t_DM介于946～1661Ma间,则反映花岗岩形成过程中有古老地壳物质混染。更多还原

【Abstract】 The granites and granodiorites in Bikai region of the southern Central-Tianshan Mountains show the characteristics of calcalkalic continental arc granites,and they were related to subduction of southern Tianshan ocean crust under Central-Tianshan block. Zircon LA-ICP-MS U-Pb dating indicates that magma activities happened between 479Ma and 401 Ma and concentrated on 419～401 Ma.The magmatic activities produced the continental margin arc of southern Central-Tianshan which was composed by calc-alkalic granitoids.(⁸⁷Sr/⁸⁶Sr)_i（=0.711578～0.704729） andε_Nd（t）（= -5.01～-2.19） suggest the addition of mantle material,and Nd model age(t_DM=946～1661 Ma) propose the old crustal material intermixed during the forming of the granitoids magma.更多还原