广西大瑶山大进花岗岩岩体的年代学、地球化学特征及其地质意义  

Geochemical Characteristics and Geological Significance of Granite Geochronology in Dayao Mountain Guangxi

作　　者：李欢[1] 刘云华[1,2] 李真[1] 周赛芳 李兴[1] 魏居珍 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]国土资源部岩浆作用成矿与找矿重点实验室,陕西西安710054

出　　处：《东华理工大学学报（自然科学版）》2016年第1期29-37,共9页Journal of East China University of Technology(Natural Science)

基　　金："广西金秀雅当铜矿成矿规律及区域找矿远景预测"资助项目(220027140128)

摘　　要：金秀大进岩体位于桂东大瑶山隆起区的西北部,侵入于寒武系地层中,岩性为中细粒花岗岩,其形成时代一直被认为是燕山期,但缺少可靠的同位素年龄数据。本文对大进岩体岩石地球化学特征进行了研究,结果表明其具有A型花岗岩的特征;利用单颗粒锆石激光探针LA-ICPMS U-Pb测年技术对花岗岩中锆石年龄进行了精确测定,获得414±11Ma成岩年龄,表明该岩体属于志留纪末期岩浆活动的产物。该岩体地质时代的厘定,表明岩体较上覆泥盆系中的沉积-改造型铜、铅锌矿床的形成时代早,暗示区域沉积-改造型铜铅锌矿床与该岩体之间无成因联系。Dajin rock of Jinxiu County,locating in the northwest area of Guidong Dayaoshan,intruded the Cambrian strata. Its lithology character is fine-grained granite. its formation age has always been considered to be in the yanshan period,but there is no reliable isotope evidence to support it. This paper analyzed the geochemical characteristics of Dajing rock mass. Results show that it has the characteristics of A-type granite. Zircon LA-ICP-MS dating for this pluton yields a（ 414 ＋ 11） Ma age,indicating it is the product of late Silurian magmatism. which is older than that of the formation of the sedimentary transformation type Cu-Pb-Zn deposit in the overlying Devonian,suggesting that there is no connection between the regional sedimentary transformation type Cu-Pb-Zn deposit and the rock mass.

关 键 词：大进岩体 锆石U-PB定年 金秀 地质意义 

分 类 号：P58[天文地球—岩石学]