渭河断裂带古地震研究  

THE STUDY OF PALEOEARTHQUAKE ON THE WEIHE FAULT ZONE

作　　者：师亚芹[1] 李晋[1] 冯希杰[1] 戴王强[1] 任隽[1] 李晓妮[1] 窦玛丽[1] 

机构地区：[1]陕西省地震局,西安710068

出　　处：《地震地质》2007年第3期607-616,共10页Seismology and Geology

基　　金：国家发展和改革委员会发改投资"城市活断层试验探测"项目(20041138)资助

摘　　要：史料记载和涵洞路槽开挖表明,在距今9110a以来渭河断裂带窑店—张家湾段曾发生1次历史地震、3次古地震事件。其中历史地震即第Ⅳ期地震的发震时间在公元1487—1568年之间;事件Ⅰ为距今(9110±90)a,事件Ⅱ和事件Ⅲ距今时间不详。第Ⅰ,Ⅱ,Ⅲ期地震事件的同震垂直位移量分别为0.5,0.5,0.2m。涵洞路槽开挖也表明,渭河断裂窑店—张家湾段为全新世活动断裂。Weihe Fault is an important buried fault in Weihe basin. The predecessors have investigated the location and activity of the fault from various points of view, but up to now, the level of researches on the precise location and activity for the fault is still very low. There are few strata profiles of late Pleis- tocene which are found to be offset by the fault zone. Especially, it is still unknown whether the Weihe Fault was active in Holocene and there were paleoseismic events occurring on it. It is indicated from exploratory trench excavated at Bili village in the west section of Weihe Fault that over the past 9110a, the Yaodian--Zhangjiawan segment of Weihe Fault zone has experienced a historical earthquake and 3 paleoearthquake events. The historical earthquake is manifested by soil liquefaction. According to the study on historical and cultural relics, stratigraphic chronology and seismogenic tectonics, we propose the occurrence time of the historical earthquake is between 1487 and 1568 ; the age of paleoseismic event Ⅰ is（9110 ±90）a, but there is no answer for the age of event Ⅱ and event Ⅲ. The coseismic vertical displacement of event Ⅰ, Ⅱ and Ⅲ is 0.5m, 0.5m and 0.2m respectively. The exploratory trench excavation also indicates that the Yaodian-Zhangjiawan segment of the Weihe Fault is a Holocene active fault.

关 键 词：渭河断裂带 古地震 同震位移 探槽 

分 类 号：P315.2[天文地球—地震学]