变质锆石成因的岩相学研究——高级变质岩U-Pb年龄解释的基本依据  

PETROGRAPHICAL STUDY OF METAMORPHIC ZIRCON: BASIC ROLES IN INTERPRETATION OF U-Pb AGE OF HIGH GRADE METAMORPHIC ROCKS

作　　者：简平[1] 程裕淇[1] 刘敦一[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037

出　　处：《地学前缘》2001年第3期183-191,共9页Earth Science Frontiers

基　　金：原地质矿产部重大基础资助项目 ( 95 0 110 2 2 ) ;国家自然科学基金资助项目 ( 4990 2 0 0 5 ) ;国土资源部同位素地质开放实验室基金;中国博士后基金资助项目

摘　　要：岩相学在研究高级变质岩 (含深熔片麻岩 )的锆石中起着重要的作用 ,其内容主要包括锆石的形貌和表面特征 ,锆石在岩石中的赋存状态 ,与主晶的关系和内部结构等方面。基于大别山地区的一些榴辉岩相岩石、麻粒岩相岩石和片麻状花岗质岩石中锆石的研究 ,阐述了继承锆石、变质锆石、深熔锆石、变质增生、深熔增生和后期流体改造的基本岩相学特征。结合大别山地区的 4个实例 ,说明了高级变质岩中锆石的岩相学研究方法和步骤 ,并初步提出了高级变质岩锆石U -Pb年龄解释的岩相学标志。Petrography plays an important role in studying zircons from high-grade metamorphic rocks and anatectic gneiss. Basically, it studies the occurrence of zircons in the rock ,the boundaries with hosting minerals, and external and internal morphology. Common features of inherited, metamorphic, anatectic zircons, metamorphic overgrowth, anatectic overgrowth, and fluid transformation are described, according to petrological observation of zircons from several eclogite facies rocks, granulite facies rocks and a gneissic granitic rock in the Dabie Mountains. Taking four examples from the Dabie area, the paper states petrographical method and the procedure in studying zircons of high-grade metamorphic rocks. Moreover, preliminary petrographical principles are proposed in the interpretation of U-Pb ages of high-grade rocks.

关 键 词：变质岩 变质锆石 深熔锆石 岩相学 U-PB年龄 大别山 成因 

分 类 号：P588.3[天文地球—岩石学]