庐山变质核杂岩核部岩体锆石LA-ICP-MS U-Pb年代学研究及其地质意义  

ZIRCON LA-ICP-MS U-Pb DATING OF GRANITIC INTRUSION IN THE CORE OF LUSHAN METAMORPHIC CORE COMPLEX AND ITS GEOLOGICAL SIGNIFICANCE

作　　者：李学刚[1] 杨坤光[1,2] 朱清波[2] 

机构地区：[1]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074 [2]中国地质大学(武汉)地球科学学院,湖北武汉430074

出　　处：《矿物岩石》2010年第4期36-42,共7页Mineralogy and Petrology

基　　金：国家自然科学基金(40972137);中国石油化工重大基础项目

摘　　要：庐山变质核杂岩是华南岩石圈伸展减薄的浅层响应,对其核部中生代中酸性岩体进行锆石LA-ICP-MSU-Pb年代学和宏观变形变质特征研究,结果表明庐山变质核杂岩核部在123.3Ma～133.0Ma期间发生过强烈的岩浆活动,且岩浆活动滞后于变质核杂岩的形成时间,岩体呈NNE向近平行带状展布,宏观上岩体不具有明显的主动侵位特征,带状岩体所处的位置可能为岩石圈伸展过程中导致的裂陷和虚脱部位。东牯山岩体中的继承锆石反映其深部存在过900Ma的岩浆活动,是江南造山带格林威尔造山事件的记录。Lushan metamorphic core complex（MCC）is the shallow response of lithospheric extending and thinning during the Mesozoic in South China.Base on the study of zircon LA-ICP-MS U-Pb geochronology and characteristics of metamorphism and deformation of Mesozoic granitic intrusions in the core of MCC,it was considered that intense magmatic activity occurred during（123.3～133.0）Ma which lags behind the formation of Lushan metamorphic core complex.Granitic intrusions are nearly parallel to NNE strike belts and the position of intrusion band may be the rifting and collapse parts of lithosphere due to extension.Macroscopically,Intrusion does not have obvious characteristics of active invasion.Inherited zircons of Donggushan intrusion indicates that there existed once 900 Ma magmatic activity in the depth of crust,which may be the record of Jiangnan Greenville orogenic event.

关 键 词：庐山变质核杂岩 U-PB年代学 岩浆作用 岩体侵位 伸展拆离 

分 类 号：P597[天文地球—地球化学]