中文摘要：

在华北克拉通东北边界带,完成了1条NW-SE走向长约900km的大地电磁测深剖面工作;该剖面西北始于中亚造山带内部的贺根山杂岩带,向SE依次穿过宝力道弧、索伦-林西缝合带、温都尔庙杂岩带、白乃庙弧、内蒙地轴、燕山造山带、最后终止于华北克拉通内部的辽河坳陷。采用大地电磁阻抗张量分解技术对所有测点的维性、区域地电走向进行了分析,沿剖面的数据具有较好的二维性。利用NLCG二维反演方法,得到了沿剖面地下二维电阻率结构。从电性结构上看,沿剖面电阻率结构具有横向分块的特征,大致可以分为3个主要的电性区,呈现高阻—低阻—高阻的变化;中亚造山带与华北克拉通显示出不同的电阻率变化特征,前者变化剧烈,后者变化相对平缓;索伦-林西缝合带和内蒙地轴中下地壳分别存在1个大范围的低阻体,可能是由深部流体以及部分熔融所致。基于研究区的深部电性结构及其他地质与地球物理观测资料,我们推测：1）西伯利亚板块与华北板块的最终缝合位置可能在锡林浩特断裂与西拉木伦河断裂之间的区域;2）燕山造山带下较厚的高阻体可能起到了构造屏障的作用,使克拉通内外的上地幔顶部具有不同的对流模式,从而减弱了中亚造山带构造演化对华北克拉通东部破坏的影响作用。

英文摘要：

Magnetotelluric data are collected along a NW-SE trending and about 900 km long profile within northeastern boundary areas of the North China craton（ NCC）. This profile extends from the Hegenshan belt within the Central Asian orogenic belt（ CAOB）,across the Baolidao arc,SolonkerLinxi suture zone,Ondor Sum accretion complex,Bainaimiao arc,Inner Mongolia paleo-uplift,Yanshan belt,and ends on the Liaohe depression of the NCC. Impedance tensor decomposition methods are used to study the dimensionality and geo-electric strike of MT data of the region. Twodimension（ 2D） analysis is appropriate for this profile. The 2-D subsurface electrical resistivity structure along profile is obtained using the non-linear conjugate gradient（ NLCG） algorithm. The electrical resistivity structure is characterized by lateral segmentation,and divided into high resistive,low resistive,and high resistive areas; The lateral variation of electrical resistivity is significant within the CAOB,but it is smooth in the NCC; The extensive high conductive body（ HRB） is observed in the mid-low crust beneath the Solonker-Linxi suture zone and Inner Mongolia paleo-uplift,respectively;The low resistivity could be due to the partial melts and crustal flows. Based on our electrical resistivity structure and other geological,geophysical observations,we speculate that（ 1） the final suturing of the Siberian craton to the NCC could be along the areas between Xilinhot Fault and Xar Moron Fault;（ 2） the relatively thick high resistive body beneath the Yanshan belt may serve as a tectonic barrier separating the on-craton and off-craton regions into different upper mantle convection system,and lower the effect of tectonic evolution of CAOB on the destruction to NCC.