银川盆地南部灵武凹陷基底构造特征  

Basement structure characteristics of the Lingwu depression in southern Yinchuan Basin

作　　者：陈晓晶 虎新军 白亚东 仵阳 陈涛涛 曹园园 倪萍 CHEN Xiao-Jing;HU Xin-Jun;BAI Ya-Dong;WU-Yang;CHEN Tao-Tao;CAO Yuan-Yuan;NI-Ping(Geophysical and Geochemical Exploration Institute of the Ningxia Hui Autonomous Region,Yinchuan 750001,China)

机构地区：[1]宁夏回族自治区地球物理地球化学勘查院,宁夏银川750001

出　　处：《物探与化探》2022年第4期862-867,共6页Geophysical and Geochemical Exploration

基　　金：宁夏回族自治区重点研发计划重大(重点)项目(2018BFG02012);宁夏深部探测方法研究示范创新团队项目(KJT2019005);宁夏自然科学基金项目(2020AAC03449、2021AAC03451);2020年宁夏回族自治区青年拔尖人才培养工程项目。

摘　　要：灵武凹陷位于银川断陷盆地东南部,受喜马拉雅期两次构造应力作用,即鄂尔多斯地块EW向的拉张应力及青藏高原NE向的挤压应力,造就了该区现今复杂的地质构造格局,为构造转折、交汇部位。自1970年以来监测到银川盆地及其周缘大于2.0级以上地震约3000余次,且大多数小震及中强地震集中于灵武凹陷范围内,存在较严重的地震灾害隐患。以往研究表明,断裂构造为地震发生的根本原因,地层是决定地震活动次生灾害的主要因素。为解译灵武凹陷基底地质构造,笔者以1∶5万区域重力资料为基础,以钻孔、地震剖面、大地电磁测深、可控源音频大地电磁测深剖面资料为约束,利用2.5D人机交互反演技术对灵武凹陷基底特征进行了精细刻画,为地震灾害防治工作提供依据。The Lingwu depression,located in the southeastern part of the Yinchuan Faulted Basin,has a complex geological tectonic framework and serves as the turning and intersection part of structures due to the two Himalayan tectonic stresses,namely the EW-direction tensile stress of the Ordos block and the NE-direction compressive stress of the Qinghai-Tibet Plateau.Since 1970,more than 3000 earthquakes with magnitudes of greater than 2.0 have been monitored in the Yinchuan Basin and its periphery.Among them,most of the small and moderately strong earthquakes occurred in the Lingwu depression,which,therefore,has serious hidden risks of earthquake disasters.Previous studies indicate that fault structures are the cause for the earthquakes and that strata serve as the main reason for the earthquake secondary disasters in this depression.To interpret the geological structures in the basement of the Lingwu depression,this study finely characterized the basement characteristics of the Lingwu depression using the 2.5D human-computer interactive inversion technology based on the 1∶50,000 regional gravity data and the constraints of data on drill holes,seismic profiles,magnetotelluric sounding,and controlled source audio-frequency magnetotellurics(CSAMT)profiles,thus providing a basis for the prevention and control of earthquake disasters.

关 键 词：灵武凹陷 1∶5万重力 2.5D人机交互反演 基底构造 

分 类 号：P631[天文地球—地质矿产勘探]