摘要
本文根据野外详实资料对张家口断裂的构造变形和活动性进行分析与研究,结果表明:断裂由西、中、东3段组成,各段多由北西向和近东西向2组多条次级断层组成,总体呈北西西走向展布,长达70km,控制着张家口及附近的第四纪构造演化和地貌发育;北西向断层构成断裂的主体,为高角度的逆(或正)走滑断层,近东西向断层较短,表现为正倾滑,第四纪期间2组断层持续活动,以脆性变形为特征;断裂端部段落与北东向断裂交汇,活动性较弱,构造表现不甚清楚,中部段落活动强烈,晚更新世以来单条断层的平均垂直活动速率大于0.07—0.30mm/a,总的垂直活动速率可能达到1.33mm/a。
Based on detailed field investigation,this paper describes geometrical characteristics and tectonic activities of Zhangjiakou fault in northwest of Beijing.This fault strikes mainly northwest to east-west,dipping to north,and extends over a length of 70km.As a major geological/and geomorphological boundary,Zhangjiakou fault controls the neotectonic movement in this region,in which its southern side is characterized by Late Quaternary unconsolidated basin deposits,and its northern side is Mesozoic volcano debris and Pre-Mesozoic metamorphic rocks in the form of lower-mountains and hills.Zhangjiakou fault are mainly of high-angle inverse strike-slip fault and partially of normal strike-slip fault.The activity of central segment of Zhangjiakou fault is stronger than other segment.Since late Pleistocene,the average vertical slip rate along single fault is over 0.07—0.30mm/a.,while the total vertical slip rate overall of entire fault is as high as 1.33mm/a.
出处
《震灾防御技术》
2010年第2期157-166,共10页
Technology for Earthquake Disaster Prevention
基金
河北省城市活断层探测与地震危险性评价项目(冀发改投资[2007]1684号)
地震行业科研专项(200908001)
关键词
张家口断裂
第四纪
构造变形
活动性
Zhangjiakou fault
Quaternary
Tectonic deformation
fault activity
