摘要
quot;EnDivSummary">The Bohai segment of the Tan-Lu Fault Zone is also called the Yingwei Fault Zone.On the basis of a series of seismic profiles,the Quaternary activities of the Yingwei Fault Zone,including fault geometry,the mode and time of the activities,and the stress field and activity,are analyzed in this study.The results show that the activities of the fault zone are extensive and intense since the Quaternary.Active faults in the zone mostly inherited Neogene faults,and are composed of eastern and western major faults.Each of the two major faults shows left-stepped,en echelon arrangement.Their steeply-dipping fault planes in the Quaternary sediments,the common Quaternary anticlines and the ENE WSW regional compression stress field all suggested that the fault zone has undergone the reverse dextral slip since the Quaternary.Many seismic profiles revealed that the active faults in the Bozhong area,the center of the Bohai Sea,are active since the Holocene,whereas in the Weibei,Laizhou Bay and Liaodong Bay areas,the active faults were alternately present in the Holocene,the Late Pleistocene and the Quaternary.Earthquake distribution shows that recent fault activity is most intense in the Bozhong area and relatively weak along the northern and southern segments.