摘要
1932年12月25日,我国甘肃省西部玉门镇以南的昌马地区发生了7.6级地震。震中区产生了规模较大的地面破裂带,其中有张性、压性和剪切等多种型式裂缝。本文根据分析各种自然破坏现象的形成条件,结合极震区地质构造特征,对震源区的应力作用和地震成因提出初步看法。对地震破裂带的分析结果表明,这次地震起主要作用的是南北向的水平挤压作用,并与自白垩纪以来控制着本区构造断裂的区域应力场是一致的。地震破裂带出现的部位与长期活动的昌马构造断裂带一致。因此,我们认为昌马地震的发生是昌马构造断裂带继承性活动的结果。
On 1932 December 25,a destructive earthquake of magnitude 7.6 occurred in the region of Changma,Kansu corridor.In the meizoseismal area,there appeared a large number of fissures and fractures,consisting of types of tension,compression and shear.In this paper,the authors analyse the forms and conditions of producing different kinds of fractures associated with the characteristics of regional tectonics,and then,propose a tentative pattern of field stress related to the seismogenesis for the present earthquake.This seismic event was principally due to the nearly north-south horizontal com-pressional force,which had long been dominating this region since the time of Cretaceous.The new seismic fractural zones appeared nearly coincided with the active area of Changma tectonic faulting.Therefore,it may be concluded that the present earthquake was an episode in the long term of Changma faulting movement.
作者
时振梁
环文林
姚国干
谢原定
SHIH CHEN-LIANG;HUAN WEN-LIN;YAO KUO-KAN;HSIE YUAN-TING
出处
《地球物理学报》
1974年第4期272-290,共19页
Chinese Journal of Geophysics
