金厂沟辉绿玢岩的年代学、地球化学及地质意义  

Geochronology,petrogeochemistry and geological significance of diabase porphyrite in Jinchanggou

作　　者：王迪 郑涛 张永胜 孙金磊 李嘉欣 Wang Di;Zheng Tao;Zhang Yongsheng;Sun Jinlei;Li Jiaxin(Department of Geology, No.602 Team of Jilin Nonferrous Metal Geological Exploration Bureau, Baishan 134300, China;College of Earth Science, Jilin University, Changchun 130061, China;National Gemological Training Center, Beijing 102628, China)

机构地区：[1]吉林省有色金属地质勘查局六○二队地质科,吉林白山134300 [2]吉林大学地球科学学院,长春130061 [3]国检珠宝培训中心,北京102628

出　　处：《黑龙江科技大学学报》2021年第5期569-577,共9页Journal of Heilongjiang University of Science And Technology

基　　金：吉林省教育厅"十三五"科学技术项目(JJKH20200946KJ);自然资源部东北亚矿产资源评价重点实验室自主基金项目(DBY-ZZ-19-13)。

摘　　要：为研究金厂沟金矿区辉绿玢岩的锆石LA-ICP-MS U-Pb年代学和岩石地球化学特征,分析金厂沟金矿区辉绿玢岩的成岩时代、岩石成因以及构造背景。结果表明:辉绿玢岩锆石U-Pb年龄为(220.3±1.2)Ma,属晚三叠世岩浆活动的产物;地球化学性质显示辉绿玢岩具有较高的碱度率,属碱性岩类;样品稀土元素配分曲线为右倾型,弱亏损Ti、Y、Nb、P、K,富集Ba、Ta、Pb等元素;La与Nb质量分数比值介于0.96~1.07,Zr与Ba质量分数比值介于0.24~0.26,显示其为软流圈来源的玄武质岩浆,样品较高的TiO_(2)、K_(2)O、P_(2)O_(5)和Zr质量分数显示其具有OIB型玄武岩的亲缘性。金厂沟辉绿玢岩形成于晚三叠纪碰撞造山后板片断离导致的伸展背景下,华北克拉通北缘东段仍受到古亚洲洋构造演化的控制。This paper is an attempt to identify the zircon LA-ICP-MS U-Pb age and petrogeochemical characteristics of diabaseporphyrites in Jinchanggou gold deposit analyzing the geochronology,prtrogenesis,and tectonic setting of samples The results show that the zircon U-Pb age is(220.3±1.2)Ma,which belongs to the magmatic activity of Late Triassic.Geochemical properties show that diabaseporphyrite has a high basicity ratio and belongs to alkaline rocks.The REE distribution curve of the sample is right-inclined,meaning the weak depletion of Ti,Y,Nb,P,K and enrichment of Ba,Ta,and Pb.The La/Nb(0.96-1.07)and Zr/Ba(0.24-0.26)ratios indicate that basaltic magma originated from asthenosphere.The higher contents of TiO_(2),K_(2)O,P_(2)O_(5) and Zr are related to OIB type basalts.The study concludes that the Jinchanggou diabase porphyrite was formed under the extensional setting caused by plate fragmentation after the Late Triassic collision orogeni and the eastern segment of the northern margin of the North China Cratonis still remains controlled by the Paleo-Asian Ocean tectonic setting.

关 键 词：金厂沟金矿 地球化学 洋岛玄武岩 锆石U-PB年龄 古亚洲洋构造域 

分 类 号：P597[天文地球—地球化学] P588[天文地球—地质学]