和林格尔地震地震地质特征的初步分析

1976年4月6日0时54分,在我国内蒙古自治区和林格尔县境内,发生了6.3级地震。宏观震中位置和仪器震中基本一致(北纬40°14′,东经112°12′)。

A PRELIMINARY STUDY OF SEISMO-GEOLOGICAL CHARACTERISTICS IN HORINGER REGION

On June 6, 1976 an earthquake of magnitude 6.3 occurred in Horinger Xian, Nei Monggol Zizhiqu of China (40°14′N, 112°12′E), located in the piedment tectonic zone of Yinshan-Yanshan (Mountains) in the northern’ part of North China faulted block. The seismicity as observed recently in this tectonic zone has clearly become more and more intensive. The earthquake area falls in an intersection of NE-trending Xindianzi-Liangcheng fault belt and NW-trending Heilaoyao-Shahukou fault belt with NNE-trending Jiucaizhuang-Haolaigou foundatioiial fault. The intensively neotectonic activity in this area resulted from superimposed effect of NW running newly formed uprise and the differential movement of NE running fault. Besides, the area studied is also characterized by distinctive differential motion of faulted block. Within the recent compressive stress field with NEE strike the "locking" of tectonic intersection leads to rapid stress accumulation on the NNE-trending foundational fault and shearing fracture resulting in the occurrence of the earthquake under unvestigation.