北京平原地区主要活动断裂带研究进展

Research Progress of Major Active Faults in Beijing Plain Area

本文通过对北京平原地区主要活动断裂的调研、分析,认识到：①北京地区的构造格局是在晚第三纪“二隆夹一凹”(京西隆起、大兴隆起和北京凹陷)的基础上发展起来的,第四纪以来这一总的格局解体。沙河凹陷在第四纪开始发育；整个北京凹陷反向抬升,与大兴隆起结为一体；大兴隆起北部则发育了顺义第四纪凹陷。②黄庄-高丽营断裂、南口-孙河断裂研究的程度相对较深入,新成果较丰富。黄庄-高丽营断裂具有明显的分段活动性质,第四纪期间断裂活动由南向北逐渐加强,最新活动表现在北段的高丽营段,活动时代为全新世,黄庄段最新活动时代为晚更新世。南口-孙河断裂是北京地区规模最大的一条北西向断裂,也是张家口-渤海地震带中一条醒目的地表第四纪活动断裂。

This paper investigates the major active faults in Beijing plain area and obtains the fol-lowing understandings.①The tectonic framework of Beijing area was developed on a basis of Neogene“one depression between two uplifts”(Jingxi uplift,Daxin uplift,and Beijing depression).Since Quaternary this general framework was disintegrated.Shahe depression started to develop in the Quaternary;the whole Beijing depression was inverted and uplif-ted,becoming an integrated part with Daxin uplift;the Quaternary Shunyi depression was developed in northern Daxin uplift.②Huangzhuang-Gaoliying fault and Nankou-Sunhe fault were relatively well studied with abundant new results.Huangzhuang-Gaoliying fault is obviously segmented,during the Quaternary faulting activities increase gradually from south to north,the most recent activity was in Holocene at the northernmost Gaoliying segment,while that on Huangzhuang segment was in Late Pleistocene.Nankou-Sunhe fault is the largest northwesterly fault in Beijing area;it is also the most striking Quater-nary fault in Zhangjiakou-Bohai seismic zone.