满洲里-绥芬河地学断面综合研究了松辽盆地西、东边界的构造特征.在由广角地震波速分布所得到的认识基础上,本文利用松辽盆地西边界带附近新实施的大地电磁测深(MT)(约470km42个测点)剖面,经过数据处理的二维电性分布,更为详细地表达了西边界带深部构造特征.与满-绥断面研究相近的结果是西边界带的断裂构造表现为作为盆地西边界的嫩江断裂,在地表附近与黑河-贺根山缝合带断裂叠加在一起,于深几公里以下两条断裂分开,缝合带断裂西倾并穿过地壳,嫩江断裂东倾而且可能不超壳.本次研究与满-绥断面研究不同点是两条断裂分开部位之下的构造表现.由于兴安微板块与松嫩微板块间碰撞、焊合以及边界断裂走滑等复杂区域应力场作用,留存的岩石圈残片被分割在嫩江断裂两侧.所建立的地质-地球物理解释模型提供了西边界带可能的构造地质作用过程.
The Manzhouli--Suifenhe geoscience transect (GGT) did a comprehensive research on the structure characteristics of the west and east boundary of the Songliao basin. Based on the understanding obtained from the wide-angle seismic velocity distribution, this paper use the 2D geoelectrical distribution along a section (about 470 kin, 42 survey points) of magnetotelluric sounding newly carried out near the western boundary of Songliao basin to describe the detailed deep structure feature of the west boundary. Compared with the Manzhouli--Suifenhe geoscience transect, the similar result is that the fault structure of the west boundary shows that the Nenjiang fault as the west boundary of the basin stacks together with the Heihe--Hegenshan suture zone near the earth's surface, and the two faults separate down several kilometers, and the fault of the suture zone tends to the west through the crust, but the Nenjiang fault tends to the east and is perhaps within the crust. The difference from the Manzhouli-- Suifenhe geoscience transect is in the structures under the part where the two faults separate. Because of the effect of the complex regional stress field, such as the collision and welding between the Xing'an microplate and Songnen micro plate and the boundary strike-slip fault, the retained lithosphere fragments is divided into the both sides of the Nenjiang fault. The established geological- geophysical interpretation model provides the feasible geological construction process of the western boundary.