皖浙赣交界莲花山岩体U-Pb锆石年龄及其地质意义  

U-Pb ZIRCON AGE OF LIANHUASHAN PLUTON IN THE JUNCTION OF ANHUI-ZHEJIANG-JIANGXI PROVINCES:Geological Implication

作　　者：刘欣[1] 伍月[1] 金珊合 LIU Xin;WU Yue;JIN Shan-he(Shenyang Center of China Geological Survey,Shenyang 110034,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034

出　　处：《地质与资源》2021年第6期666-674,682,共10页Geology and Resources

基　　金：国家自然科学基金项目“华北板块北缘东段法库地区早古生代弧岩浆活动及其构造演化特征”(编号41902234);中国地质调查局地质调查项目:“辽东-吉中地区区域地质调查”(编号DD20190042-02).

摘　　要：皖浙赣交界莲花山岩体位处扬子板块东南缘,即扬子板块与华夏板块结合带之东段(江南造山带东段北缘).该岩体侵入于新元古代末期的上墅组(赣东北),岩性主要为正长花岗岩及花斑岩,后期因变质变形作用而发生面理化并具有绿片岩相浅变质矿物组合.地球化学特征指示,莲花山花岗岩很有可能为形成于大陆边缘后造山环境的A_(2)型花岗岩.锆石LA-ICP-MS U-Pb定年结果显示岩体年龄为878±70 Ma,为晋宁晚期的产物.The Lianhuashan pluton in the junction of Anhui-Zhejiang-Jiangxi provinces is located in the southeast margin of Yangtze Plate,namely the junction zone of Yangtze Plate and Cathaysia Plate(the northern margin of eastern section of Jiangnan orogenic belt).The pluton intruded into the late Neoproterozoic Shangshu Formation(northeastern Jiangxi),with the lithology of syenogranite and granophyres.In later period,the metamorphic deformation resulted in foliated and greenschist facies epimetamorphic mineral assemblage.The geochemical characteristics indicate that the Lianhuashan granite is probably A_(2) type formed in continental margin post-orogenic environment.The zircon LA-ICP-MS U-Pb dating of the pluton yields the age of 878±70 Ma,which is the product of late Jinning Period.

关 键 词：江南造山带 莲花山花岗岩 锆石LA-ICP-MS U-Pb定年 地球化学特征 岩石成因 

分 类 号：P597.3[天文地球—地球化学]