东昆仑造山带后碰撞花岗岩岩石地球化学和^(40)Ar/^(39)Ar同位素年代学约束  

Constraints of Petrochemistry and ^(40)Ar/^(39)Ar aging of post-collision granites in Eastern Kunlun Orogenic Belt

作　　者：刘成东[1] 周肃[1] 莫宣学[1] 罗照华[1] 喻学惠[1] 李述为[1] 赵欣[1] 

机构地区：[1]中国地质大学

出　　处：《华东地质学院学报》2003年第4期301-305,共5页Journal of East China Geological Institute

基　　金：中国地质调查局重点项目"花岗岩重大地质问题研究"(2 0 0 1 1 390 0 0 1 8);国家重点基础研究发展规划项目(G1 9980 4 0 80 0 ;2 0 0 2CB41 2 60 0 )。

摘　　要：野外地质和室内岩相学、岩石地球化学特征研究表明 ,东昆仑造山带存在大量后造山期花岗岩。在此基础上 ,对其重要地段的典型样品进行了4 0 Ar/39Ar同位素年龄测定 ,分别得到 14 2 .14± 1.98Ma ,2 0 7.3 5± 0 .86Ma和 2 2 3 .6± 1.3Ma三个坪年龄。结果表明 ,本地区印支末期已经进入后造山作用阶段 ,该阶段延续时间可能较长 ,一直延续到燕山期———典型的陆内碰撞时期。本文从岩石地球化学和同位素年代学角度对本区酸性岩浆活动的构造环境和时限进行了制约。There exist lots of post-collision granites in Eastern Kunlun, based on the field geological work, petrography and petrochemistry study. The ^(40)Ar/^(39)Ar isotope ages of typical samples were determined and 142.14±1.98 Ma,207.35±0.86 Ma and 223.6±1.3 Ma are obtained. It concludes that the post-collision event was taken place in the late Indosinian epoch and it might last a long time, till to Yanshan. And the Yanshan magmatism was in the tectonic environment of inner-plate. The time and the tectonic environment of the acid magmatism in the Eastern Kunlun orogenic belt is constrained in this paper.

关 键 词：花岗岩 构造环境 地球化学 ^40Ar/^39Ar同位素年代学 东昆仑 

分 类 号：P597[天文地球—地球化学]