论文部分内容阅读
1933年迭溪7.5级地震震区位于我国东西两大块体过渡带——“中国南北构造带”的中段。区内构造复杂,几个不同构造体系的构造成分互相牵制、干扰、复合,还有引人注目的较场弧形构造及其西翼的北西向断裂带。新构造运动表现为强烈抬升背景上的断块差异运动和局部褶断特征。根据对航磁、重力资料的分析,划分出五个磁异常区(带),并作了相应的构造解释。从地震地裂缝、建筑物变形特征、地震崩塌滑坡定向性所反映的应力场以及烈度分布、震源机制解,推测迭溪7.5级地震是在北东东或近东西向的区域构造应力场作用下,导致北西向的松坪沟断裂发生反时针水平错动的结果。故认为松坪沟断裂是迭溪地震的发震构造,而刷金寺——迭溪东西向隐伏断裂带也起了一定的阻隔、牵制以至应力加强的作用。
The Diexi 7.5 magnitude earthquake in 1933 is located in the middle of the two block transitional zones of east and west China - the “north-south structural belt of China.” The structure in the area is complex. The tectonic components of several different tectonic systems interlace, interfere with and recombine with each other, as well as the striking comparatively arcuate structure and the north-west fault zone of the west wing. The neotectonic movement is characterized by differential block motion and local pleat-fold features on a strongly uplifted background. Based on the analysis of aeromagnetic and gravity data, five magnetic anomalous zones (belts) are divided and corresponding structural explanations are given. From the seismic ground fissures, deformation features of buildings, the stress field and intensity distribution reflected by earthquake collapse and landslide orientation, and focal mechanism solutions, it is speculated that the Duxi 7.5 earthquake is caused by the tectonic stress field in the NE or near EW , Resulting in the northwest of the Songpinggou fracture anti-clockwise level of the results of the move. Therefore, it is considered that the Songpinggou fault is the seismogenic structure of Diexi earthquake, and the brush gold temple-Diexi east-west buried fault zone also plays a certain role in blocking, restraining and even strengthening the stress.