• 首页
  • 学报简介
  • 编委会
  • 投稿指南
  • 订阅指南
  • 过刊浏览
  • 在线投稿
  • 联系我们
  • 网络预出版
  • English

本文将参加年度优秀论文评选,如果您觉得这篇文章很好,请投下您宝贵的一票,谢谢! 支持(0)   不支持(0)

华北陆块北缘尚义地区下井-厂汉营韧性剪切带变形特征及年代学研究
投稿时间:2020-07-14  修订日期:2020-10-13  点此下载全文
引用本文:
DOI:10.19762/j.cnki.dizhixuebao.2021058
摘要点击次数: 64
全文下载次数: 68
作者单位地址
李亚东 昆明理工大学国土资源工程学院地球科学系 云南省昆明市昆明理工大学莲华校区地矿楼503
柳永清 中国地质科学院地质研究所 
江小均 昆明理工大学国土资源工程学院地球科学系 云南省昆明市昆明理工大学莲华校区地矿楼503
李超 国家地质实验测试中心 
彭楠 中国地质科学院地质研究所 
严清高 昆明理工大学国土资源工程学院地球科学系 
王忠强 昆明理工大学国土资源工程学院地球科学系 
甘熙 云南驰宏锌锗股份有限公司 
基金项目:中国地质调查局 (编号;12120110200150009)、云南省科学技术奖-杰出贡献奖(编号;2017001)和云南省应用基础研究计划青年(编号:2016DF031)
中文摘要:内容提要:华北陆块北缘晚古生代经历了多期构造事件,构造活动复杂多样,位于其中段的下井-厂汉营韧性剪切带构造变形强烈,研究韧性剪切带变形特征以及形成时代,对进一步探讨华北陆块北缘晚古生代构造演化特别是古亚洲洋晚阶段洋壳俯冲的时间和机制有重要意义。鉴于此,对该韧性剪切带进行了运动学和几何学实测剖面、显微构造解析及锆石LA-ICP-MS U-Pb年代学等综合研究,以期限定韧性剪切带变形特征和时间。 剪切带内原岩为一套闪长质-花岗质岩浆岩,后期遭受走滑剪切作用形成花岗质糜棱岩和闪长花岗质糜棱岩以及构造深融作用析出同变形钾长花岗质糜棱岩脉,后期被未变形的角闪辉绿岩脉所侵位,从而划分出变形前期花岗质-闪长花岗质糜棱岩、同变形期细脉状钾长花岗质糜棱岩和变形期后未变形角闪辉绿岩3个阶段。 其中糜棱岩面理近E-W或SW-NE走向,倾向NW-N,倾角较陡,线理倾伏向为SW向,倾伏角较缓,带内发育拉伸线理、S-C组构、不对称褶皱、旋转残斑、多米诺碎斑等宏观和微观构造,指示剪切带性质为左行走滑剪切变形特征。采集变形前期、同变形期和变形后期岩石进行锆石LA-ICP-MS U-Pb年代学研究,获得3期锆石206Pb/238U协和年龄为286.7±4.1Ma、280.0±5.5Ma和278.8±0.57Ma,最终认为下井-厂汉营韧性剪切带左行走滑变形的时代为~280Ma,即早二叠世晚期。综合区域中亚造山带南缘构造-岩浆时代、动力学背景及演化过程资料,认为下井-厂汉营韧性剪切带形成于中亚造山带东南缘兴安俯冲-增生造山带挤压闭合到索伦-西拉木伦河一线造山后伸展构造转换调节作用。
中文关键词:韧性剪切带  华北陆块北缘  左行走滑剪切  锆石U-Pb年代学  构造转换
 
1) Department of Earth Sciences, Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming, 650093, China2) National Research Center for Geoanalys, Beijing 100037, China
Author NameAffiliationAddress
liyadong Department of Earth Sciences, Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 云南省昆明市昆明理工大学莲华校区地矿楼503
liuyongqing Institute of Geology, Chinese Academy of Geological Sciences 
jiangxiaojun Department of Earth Sciences, Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 云南省昆明市昆明理工大学莲华校区地矿楼503
lichao National Research Center for Geonalysis 
pengnan Institute of Geology, Chinese Academy of Geological Sciences 
yanqinggao Department of Earth Sciences, Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 
wangzhogqiang Department of Earth Sciences, Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 
ganxi Yunnan Chihong Zn & Ge Company LTD 
Abstract:The northern margin of North China block experienced multiple tectonic events in the late Paleozoic, with complex and diverse tectonic activities. The Xiajing-changhanying ductile shear zone located in the middle segment of the North China block had a strong tectonic deformation. The study of the deformation characteristics and formation age of the ductile shear zone is of great significance to further explore the tectonic evolution of the northern margin of the North China block, especially the time and mechanism of oceanic subduction crust in the late stage of Paleo-Asian Ocean. In view of this, the kinematic and geometric profiles, microstructural analysis and zircon LA-ICP-MS U-Pb geochronology of the ductile shear zone were carried out in order to define the deformation characteristics and time of the ductile shear zone. The protoliths in the shear zone are a set of dioritic-granitic magmatic rocks, which were formed by strike slip shearing in the later stage, and the synmorphic K-feldspar granitic mylonite veins were precipitated by the tectonic deep melting, and were emplaced by the undeformed hornblende diabase veins in the later stage, thus divided into the early stage of the deformation of granitic diorite - granitic mylonite, long with deformation fine vein potassium granitic mylonite and post deformation undeformed amphibolite diabase three stages. Among them, mylonite foliation is close to E-W or SW-NE trend, inclining to NW-N, with steep dip angle, SW dip direction and gentle dip angle. Macro and micro structures such as tensile lineation, S-C fabric, asymmetric fold, rotary remnant and domino porphyroclastic structure are developed in the zone, indicating that the nature of the shear zone is characterized by left lateral strike slip shear deformation. Zircon LA-ICP-MS U-Pb geochronology of the early, syn and post deformation rocks was carried out. The zircon 206Pb / 238U concordant ages of 286.7 ± 4.1Ma, 280.0 ± 5.5Ma and 278.8 ± 0.57Ma were obtained. It is concluded that the age of left strike slip deformation in Xiajing-changhanying ductile shear zone is ~ 280Ma, that is, the late Early Permian. Based on the data of tectonic magmatic age, dynamic background and evolution process in the southern margin of the Central Asian orogenic belt, it is considered that the Xiajing-changhanying ductile shear zone was formed during the compression of the Xing"an subduction accretionary orogenic belt on the southeastern margin of the Central Asian orogenic belt to the post orogenic extensional tectonic transformation along the Solun Xilamulun river line.
keywords:ductile shear zone  northern margin of North China block  sinistral strike slip shear  zircon U-Pb geochronology  structural transformation
查看全文  查看/发表评论  下载PDF阅读器
您是第37420555位访问者  京ICP备05032737号-7  
版权所有:《地质学报》中文版
主管单位:中国科学技术协会 ; 主办单位:中国地质学会
地  址: 北京市西城区百万庄大街26号; 邮编:100037 ; 电话:010-68312410,010-68999025; E-mail: dizhixuebao@163.com
本系统由北京勤云科技发展有限公司设计 

京公网安备 11010202007916号

WeChat