新疆中天山南缘比开(地区)花岗岩地球化学特征及年代学研究  

Geochemistry and geochronology of granitoids in Bikai region,southern Central-Tianshan mountains,Xinjiang

作　　者：龙灵利[1] 高俊[1] 熊贤明[1] 钱青[1] 

机构地区：[1]中国科学院地质与地球物理研究所矿产资源重点实验室

出　　处：《岩石学报》2007年第4期719-732,共14页Acta Petrologica Sinica

基　　金：国家自然科学基金(编号:40672153;40421202);国家重点基础研究发展规划项目(编号:2001CB409803)资助

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。(^(87)Sr/^(86)Sr)_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。The granites and granodiorites in Bikai region of the southern Central-Tianshan Mountains show the characteristics of calc- alkalic 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 401Ma and concentrated on 419-401Ma. The magmatic activities produced the continental margin arc of southern Central-Tianshan which was composed by calc-alkalic granitoids. （ ^87 Sr/^86 Sr） ; （ = 0- 711578 - 0. 704729 ） and εNd（ t ） （ = - 5.01～ - 2. 19 ） suggest the addition of mantle material, and Nd model age （tDM = 946-1661 Ma） propose the old crustal material intermixed during the forming of the granitoids magma.

关 键 词：新疆 中天山 比开花岗岩 地球化学 LA-ICP-MS锆石U-PB年龄 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]