摘要
夏垫断裂是1679年三河-平谷8级地震的发震断层,在其西侧发现一条新的断裂,称其为夏垫西断裂。文中采用6条浅层地震剖面确定了该断层在三河市内的位置;采用联排钻孔探测方法并应用磁化率测井技术,结合释光测年,研究了该断裂的晚第四纪活动性。该断裂蜿蜒曲折,总体走向NE,倾向NW。在垂直剖面上表现为正断层性质,它是燕郊半地堑型断陷东南缘的主控断裂。该断裂与夏垫断裂倾向相反,与夏垫断裂之间夹一地垒,地垒最窄处<1km。由10个钻孔的岩心柱状图和测井曲线及8个有效的测年数据组成的钻孔联合剖面显示,该隐伏断裂的上断点埋深约为12m,错断了晚更新世晚期地层,错断的最新地层的测年结果为(36.52±5.39)ka。晚更新世以来的垂直滑动速率约为0.075mm/a,晚更新世晚期以来的滑动速率约为0.03mm/a。该断裂在平面上可能与夏垫断裂组成雁列构造,二者在深部存在密切的联系,同属于一条切过整个地壳的深大断裂。
Beijing plain is a strong earthquake tectonic area in China,where the Sanhe-Pinggu earthquake with M8 occurred in 1679.The seismogenic fault of this earthquake is the Xiadian Fault.An about 10km-long earthquake surface fault is developed,striking northeast.Deep seismic exploration reveals that this surface fault is a direct exposure of a deep fault cutting through the whole crust,and it is concealed in the Quaternary layers to both ends.Previous studies have not yet revealed how the deep fault with M8 earthquake extended to the southwest and northeast.In the study of Xiadian Fault,it is found that there is another fault with similar strike and opposite dip in the west of Xiadian Fault,which is called the West Xiadian Fault in this paper.In this study,six shallow seismic profiles data are used to determine the location of this fault in Sanhe city,and the late Quaternary activity of the fault is studied by using the method of combined drilling,magnetic susceptibility logging and luminescence dating.The results of shallow seismic exploration profiles show that the fault is zigzag with a general strike of NE and dip NW.In vertical profile,it is generally of normal fault.It shows the flower structure in one profile,which indicates that the fault may have a certain strike-slip property.On two long seismic reflection profiles,it can be seen that the northwest side of the fault is a half graben structure.This half graben-like depression,which has not been introduced by predecessors,is called Yanjiao fault depression in this paper.The maximum Quaternary thickness of the graben is 300m.The West Xiadian Fault is the main controlling fault in the southern margin of the sag.The Xiadian Fault,which is opposite to the West Xiadian Fault in dips,controls the Dachang depression,which is a large-scale depression with a Quaternary thickness of more than 600m.The West Xiadian Fault is opposite to the Xiadian Fault,and there is a horst between the West Xiadian Fault and the Xiadian Fault.The width of the horst varies greatly,and the
作者
沈军
戴训也
肖淳
焦轩凯
白其乐格尔
邓梅
刘泽众
夏方华
刘玉
刘明
SHEN Jun;DAI Xun-ye;XIAO Chun;JIAO Xuan-kai;BAI Qilegeer;DENG Mei;LIU Ze-zhong;XIA Fang-hua;LIU Yu;LIU Ming(Key Laboratory of Seismic Dynamics of Hebei Province,Sanhe 065201,China;Institute of Disaster Prevention,Sanhe 065201,China;Industry and Information Technology Bureau of Shuicheng District of Liupanshui City,Liupanshui 553000,China;Beijing Huan’an Engineering Inspection&Test Co.Ltd.,Beijing 100026,China;Exploration Unit of North China Geological Exploration Bureau,Sanhe 065201,China)
出处
《地震地质》
EI
CSCD
北大核心
2022年第4期909-924,共16页
Seismology and Geology
基金
国家自然科学基金(42172253,41372216)
中央高校基本科研业务专项(ZY20160211)共同资助。
关键词
北京平原
夏垫西断裂
晚第四纪活动性
联排钻孔探测
浅层地震勘探
Beijing plain
West Xiadian Fault
late Quaternary activity
row drilling exploration
shallow seismic exploration
