时间: 2022-09-10 | 次数: |
文艺洁, 李雪, 李谦超,等.扬子地块东缘上海地区泥盆纪岩浆岩特征及其构造意义[J].河南理工大学学报(自然科学版),2022,41(5):46-57.
WEN Y J, LI X, LI Q C, et al.Characteristics and tectonic significance of the Devonian magmatite in Shanghai Area,eastern Yangtze Block[J].Journal of Henan Polytechnic University(Natural Science) ,2022,41(5):46-57.
扬子地块东缘上海地区泥盆纪岩浆岩特征及其构造意义
文艺洁1, 李雪2, 李谦超1, 王永昊3, 杨思怡3, 郭涵1, 张志伟4, 邱亮3, 颜丹平3
1.中国地质大学(北京) 能源学院,北京 100083;2.上海市地矿工程勘察(集团)有限公司,上海 200072;3.中国地质大学(北京) 地球科学与资源学院,北京 100083;4.中国地质调查局 自然资源实物地质资料中心,河北 廊坊 065201
摘要:为了揭露扬子地块早古生代岩浆作用特征,厘定加里东构造事件影响范围,以上海地区基岩岩心中安山岩为研究对象,在总结钻孔资料基础上,进行岩石学鉴定、阴极发光测试、锆石U-Pb年代学和微量元素分析。结果表明:镜下观察显示,该岩石基质中含有斜长石、辉石、安山质玻璃等,晶屑以斜长石、中长石和黑云母为主,并可见被方解石充填形成的杏仁状构造;阴极发光显示,锆石内部结构为棱柱状自形结构,多发育震荡环带,表现出典型岩浆锆石特征;U-Pb定年和微量元素分析显示,锆石w(206Pb)/w(238U)平均年龄为(410.5±1.8) Ma;微量元素测试进一步显示锆石为陆壳起源。结合华南大地构造背景研究,认为华南加里东早古生代岩浆活动产生的背景可能为陆内造山带后期的伸展环境。
关键词:上海地区;泥盆纪;岩浆岩;加里东构造事件;年代学
doi:10.16186/j.cnki.1673-9787.2020080086
基金项目:国家自然科学基金资助项目(41702207,42030306)
收稿日期:2020/08/28
修回日期:2020/10/16
出版日期:2022/09/25
Characteristics and tectonic significance of the Devonian magmatite in Shanghai Area,eastern Yangtze Block
WEN Yijie1, LI Xue2, LI Qianchao1, WANG Yonghao3, YANG Siyi3, GUO Han1, ZHANG Zhiwei4, QIU Liang3, YAN Danping3
1.School of Energy,China University of Geosciences(Beijing),Beijing 100083,China;2.Shanghai Geological Engineering Exploration(Group) Co.,Ltd.,Shanghai 200072,China;3.School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;4.Cores and Samples Center of Nature Resources,China Geological Survey,Langfang 065201,Hebei,China
Abstract:In order to reveal the characteristics of early Paleozoic magmatism in the Yangtze Block and to determine the scope of influence of the Caledonian tectonic events,the andesites from drill cores in Shanghai Area were identified by microscopy,the zircons incorporated in were separated and then imaged by cathodoluminescence(CL).The CL images showed prismatic and pyramidal crystal forms and magmatic oscillatory,indicating an igneous origin.The zircons yielded a weighted mean U-Pb age of(410.5±1.8)Ma.Furthermore,the geochemistry of the zircons indicated a continental origin.Therefore,It was proposed that the newly discovered Devonian andesite had an affinity of post-orogenic extension of the early Paleozoic orogen.
Key words:Shanghai Area;Devonian;magmatic rock;Caledonian tectonic event;geochronology