贺兰山构造带深部电性结构与动力学机制  

Deep electrical structure and dynamic mechanism of the Helanshan tectonic belt

作　　者：徐大兴 邵兆刚[1,3] 陈宣华[1,3] 张进江[2] 徐盛林[1,3] 李冰[1,3] 张义平[1,3] 余苇 邓文兵 丁奕文 XU Daxing;SHAO Zhaogang;CHEN Xuanhua;ZHANG Jinjiang;XU Shenglin;LI Bing;ZHANG Yiping;YU Wei;DENG Wenbing;DING Yiwen(Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China;SinoProbe Laboratory/Chinese Academy of Geological Sciences,Beijing 100094,China;School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,Anhui,China;Exploration and Research Institute,Anhui Bureau of Coal Geological Exploration,Hefei 230088,Anhui,China;Cores and Samples Center of Natural Resources,China Geological Survey,Sanhe 065201,Hebei,China)

机构地区：[1]中国地质科学院,北京100037 [2]北京大学地球与空间科学学院,北京100871 [3]自然资源部深地科学与探测技术实验室/中国地质科学院,北京100094 [4]合肥工业大学资源与环境工程学院,安徽合肥230009 [5]安徽省煤田地质局勘查研究院,安徽合肥230088 [6]中国地质调查局自然资源实物地质资料中心,河北三河065201

出　　处：《地质通报》2024年第11期1921-1936,共16页Geological Bulletin of China

基　　金：中国地质调查局项目《深部地质调查》(编号:DD20230008);《西北重要构造廊带深部地质调查》(编号:DD20230229);《鄂尔多斯盆地及周缘地质构造调查》(编号:DD20242780);中国地质科学院与中国石油长庆油田分公司合作项目《鄂尔多斯盆地西部及其周缘断裂系统与构造演化综合研究》(编号:2021DA0404);《鄂尔多斯盆地西部综合地球物理调查工程》(编号:ZY20-XA202-TPGC272);中国地质科学院基本科研业务费项目《鄂尔多斯盆地西部断裂系统与构造演化研究》(编号:JKY202207)。

摘　　要：贺兰山构造带是华北克拉通西部中生代以来的典型陆内构造变形区域。对野外采集的大地电磁数据进行分析与反演,获取贺兰山构造带的深部电性结构。结果揭示,贺兰山构造带上地壳发育逆冲推覆构造,中下地壳存在完整且厚实的地壳根。大地电磁测深剖面显示,贺兰山构造带西北部的河套盆地深部存在向NW方向上涌的低电阻率通道,东南部的银川地堑与鄂尔多斯盆地存在地幔物质上涌的特征。贺兰山构造带晚侏罗世WNW—ESE向挤压的褶皱冲断带与白垩纪以来的构造隆升过程和西太平洋板块俯冲作用相关,记录了早期深部地幔物质向NW方向上涌的现象。在新生代西太平洋板块持续俯冲与回撤过程中,以及青藏高原向东北缘扩展的联合控制下,贺兰山构造带的邻区深部地幔物质向地壳上涌,导致鄂尔多斯盆地深部岩石圈发生减薄,地幔物质与地壳发生交代作用,在刚性的贺兰山块体限制下,形成现今的盆山构造格局。Helanshan tectonic belt is a typical intracontinental contractional deformation area of the western North China Craton since the Mesozoic.Based on the analysis and inversion of magnetotelluric data collected in the field,the deep electrical structure of the Helanshan tectonic belt was obtained.The results reveal that the Helanshan tectonic belt develops the thrust-nappe structure in the upper crust,and there are intact and thick crustal roots in the middle and lower crust.The magnetotelluric sounding profile shows that there is a low resistivity channel upwelling to the NW of the Helanshan tectonic belt,and there are mantle material upwelling characteristics in the Yinchuan Garben and Ordos Bain in the southeast.The Helanshan tectonic belt of the Late Jurassic WNW—ESE compressive fold-thrust belt and the Cretaceous tectonic uplift process are related to the subduction of the Western Pacific Plate,which records the early upwelling of deep mantle material in the NW direction.Controlling by the Cenozoic Western Pacific Plate subduction and rollback and the Tibetan Plateau growth northward,the adjacent area of the Helanshan tectonic belt deep mantle material upwelling into the crust.Then,the Ordos Basin deep lithosphere thinned,forming the present basin and mountain tectonic pattern.

关 键 词：贺兰山构造带 大地电磁 深部电性结构 上涌通道 深部动力学机制 

分 类 号：P54[天文地球—构造地质学] P631.325[天文地球—地质学]