北山及邻区晚古生代基性岩墙群几何特征及构造意义--基于遥感影像研究  

Geometric characteristics and tectonic significance of Late Paleozoic mafic dyke swarms in Beishan and its adjacent areas--Based on remote sensing image research

作　　者：常旺 张贵山[1,2] 彭仁 温汉捷 刘磊 张磊[1,2] 孟乾坤 王亮[1] CHANG Wang;ZHANG Guishan;PENG Ren;WEN Hanjie;LIU Lei;ZHANG Lei;MENG Qiankun;WANG Liang(School of Earth Science and Resources,Chang’an University,Xi’an 710064,Shaanxi,China;Engineering Technology Innovation Center of New Energy Minerals and Resource Information,Ministry of Natural Resources,Xi’an 710054,Shaanxi,China)

机构地区：[1]长安大学地球科学与资源学院,陕西西安710064 [2]自然资源部新能源矿产与资源信息工程技术创新中心,陕西西安710054

出　　处：《地质通报》2024年第4期536-545,共10页Geological Bulletin of China

基　　金：国家自然科学基金面上项目《闽西及邻区晚中生代基性岩墙群年代学和地球化学研究》(批准号:41073027);陕西省自然科学基金面上项目《甘肃北山晚古生代基性岩墙群年代学和地球化学:塔里木地幔柱证据》(编号:2019JM-161)。

摘　　要：北山及邻区广泛发育晚古生代基性岩墙群,反映了该地先存裂隙(节理)的区域构造应力场和岩墙群形成后经历的构造活动,对探究岩浆活动、反演构造演化过程及分析岩墙几何特征与构造应力之间的耦合关系具有重要意义。综合遥感和地质方法,在遥感影像中解译提取1777条基性岩墙,通过几何工具计算得到岩墙走向数据,总结岩墙群空间分布规律,同时与其形成时的大陆动力学演化背景相对应。结果表明,北山及邻区岩墙优势走向方位集中于0°~65°与320°~360°,绝大部分岩墙是在伸展作用中张性区域应力场控制下形成的,具张性性质或剪张性性质,部分岩墙受后期碰撞挤压环境影响,具张剪性性质。岩墙群主导成因机制是区域伸展构造作用,兼以地幔柱远程效应及热点作用。Late Paleozoic mafic dyke swarms are widely developed in Beishan and it’s adjacent areas,which reflect the regional tectonic stress field of the pre-existing fissures(joints)and the tectonic activities experienced after the formation of dyke swarms,and are of great significance for exploring magmatic activities,inverting the tectonic evolution process,and analyzing the coupling relationship between the geometric characteristics of the dyke and the tectonic stress.Combining remote sensing and geological methods,this paper interprets and extracts 1777 basic dykes from remote sensing images,calculates the trend data of dykes through geometric tools,summarizes the spatial distribution of dyke swarms,and discusses the genetic mechanism of dyke swarm in the study area corresponding to the continental dynamic evolution background when they were formed.The dominant strike directions of the dyke in the Beishan and its adjacent areas are concentrated in 0°~65°and 320°~360°.Most of the dyke are formed under the control of the tensile regional stress field during the regional extension and have tensile or shear properties,while some of the dykes are affected by the late collision and extrusion environment and have the properties of tensile shear.The dominant genetic mechanism of dyke swarms is regional extensional tectonics,and also the remote effect and hot spot effect of mantle plume.

关 键 词：遥感地质 基性岩墙群 几何特征 区域构造应力场 北山 

分 类 号：P534.5[天文地球—古生物学与地层学] P588.124[天文地球—地质学] P627