华北克拉通中西部地区的地壳结构研究  

STUDY ON THE CRUSTAL STRUCTURE OF THE CENTRAL AND WESTERN PART OF THE NORTH CHINA CRATON

作　　者：潘纪顺[1] 李朋辉 段永红[2] 赵延娜[2] 彭诣淙 孙凯旋 PAN Ji-shun;LI Peng-hui;DUAN Yong-hong;ZHAO Yan-na;PENG Yi-cong;SUN Kai-xuan(North China University of Water Resources and Electric Power,Zhengzhou 450046,China;Geophysical Exploration Center,China Earthquake Administration,Zhengzhou 450002,China;Geological Exploration Institute,the First Exploration Bureau,CNACG,Handan 056004,China)

机构地区：[1]华北水利水电大学,郑州450046 [2]中国地震局地球物理勘探中心,郑州450002 [3]中国煤炭地质总局第一勘探局地质勘查院,邯郸056004

出　　处：《地震地质》2021年第5期1269-1291,共23页Seismology and Geology

基　　金：国家自然科学基金(41774066);中国地震局地球物理研究所基本科研业务专项(DQJB16A03,DQJB17A01)资助。

摘　　要：华北克拉通是中国最古老的克拉通,是中国大陆的主要构造单元,从太古代到中生代以来的地质记录较完整,受到了国际上的广泛关注,是研究大陆形成和演化的天然实验场地。中生代以后,华北克拉通发生了一系列复杂的构造运动与演化进程,东部因岩石圈减薄而形成一系列的裂陷盆地,地壳结构复杂。而西部岩石圈厚度大,鄂尔多斯地块的地壳结构相对简单。山西断陷带位于华北克拉通东部地块与西部鄂尔多斯地块之间,其地壳与岩石圈结构从西部稳定的克拉通结构变化为东部破坏严重的克拉通结构,过渡特征明显。因此,揭示山西断陷带及其两侧区域的构造特征对研究华北克拉通的破坏动力学过程有着重要意义。文中利用华北克拉通中西部地区(34°~41°N,107°~117°E)的150个流动地震台站近3a记录的远震波形资料,采用P波接收函数的H-κ扫描叠加法和共转换点(CCP)叠加法处理计算,获得了研究区的地壳速度结构图像。结果表明,鄂尔多斯地块内的地壳厚度为37~47km,莫霍面较为平坦。山西断陷带的地壳厚度为34~46km,在临汾盆地凹陷的正下方,莫霍面呈现出明显的上隆,上隆量为4~10km,推断山西断陷带的形成与地幔物质的运动有着密切关系。通过与该区域已有的布格重力异常资料进行对比,研究区地壳厚度的分布特征与太行隆起东、西部地区分别呈现出正、负的布格重力异常分布特征一致。该区域不同构造单元内的地壳厚度和波速比计算结果表明,3个构造单元内的波速比均随地壳厚度的增加而不同程度地减小。整体看来,研究区以111.5°E为界分为东、西2个区,111.5°E以西的鄂尔多斯地区的泊松比较111.5°E以东的山西断陷带低,反映出鄂尔多斯地块东部地区具有稳定的古老地块特征,地壳结构相对简单;而山西断陷带下方上地幔物质上涌导致其泊松比比两侧山区的泊松�The North China Craton is the oldest craton in China and also the main tectonic unit of the Chinese mainland.The geological marks from Archean to Mesozoic era are complete and have attracted scientists all over the world.It has been the natural experimental site for the study of continental formation and evolution.A series of complex tectonic movement and evolution processes occurred in the North China Craton since Mesozoic.A series of rift basins were formed due to the thinning of lithosphere in its eastern part,so its crust structre is complicated.But the lithosphere is thick in its western part,so the crust structure of the Ordos block is simple.Shanxi rift zone is located between the eastern block of North China Craton and the western Ordos block.The crust and lithosphere structure of Shanxi rift zone is changed from stable craton structure in the west to severely damaged craton structure in the east,showing obvious transition characteristics.Therefore,it is of great significance to study the structural characteristics of the Shanxi rift zone and its two sides so as to reveal the failure dynamics of the North China Craton.Based on the teleseismic waveform data recorded by 150 mobile seismic stations in the central and western part of the North China Craton(107°E~117°E;34°N~41°N)in the recent three years,the crustal velocity structure images of the study area are obtained by using the H-κstacking method of P-wave receiver function and the common conversion point(CCP)superposition method.Our research results show that the crustal thickness in the Ordos block is between 37km and 47km,the Moho surface is relatively flat.The crust thickness of Shanxi rift zone is between 34km and 46km.Under the depression of Linfen Basin,Moho surface shows obvious uplift,and the uplift amount is between 4km and 10km.It is inferred that the formation of Shanxi rift zone is closely related to the movement of mantle materials.Compared with the existing Bouguer gravity anomaly data in this area,the distribution characteristics of

关 键 词：接收函数 鄂尔多斯地块 山西断陷带 H-κ扫描叠加 共转换点叠加 地壳结构 

分 类 号：P315.2[天文地球—地震学]