利用钻/测井、三维地震等资料,在断层活动速率统计的基础上,分析了渤海海域北部秦南凹陷东南缘古近系边界断层活动演化特征,并探讨了边界断层活动对沉积的控制作用.研究表明:研究区边界断层具有明显的分段性,且由石北1西、石北1东、石北2西、石北2东等4段组成.纵向上,孔店组至沙四段沉积期,边界断层开始活动,且活动性较弱;沙三段沉积期,断层活动增强;沙一+二段沉积期,断层活动性减弱;东三段沉积期,断层活动再次增强,东二段沉积期,断层活动逐渐减弱,至东一段沉积期,断层停止活动.平面上,同一地质时期不同段的边界断层均表现为中部强、两端弱的特点.空间上,同一位置的断层活动性具有继承性.边界断层活动的差异性控制了盆地的差异升降,导致物源区的差异剥蚀,并形成了不同的沉积格局和构造转换带,进而对物源区的剥蚀以及沉积区的沉降速率、沉积相类型、沉积相分布、三角洲的延伸距离、岩性具有重要的控制作用.%Drilling/logging,3D seismic data and other information were combined with fault activity rate statistics to ana-lyze quantitatively the characteristics of the Paleogene boundary fault activities and their control over sedimentation in southeastern margin of Qinnan Sag,Bohai sea.The result shows the boundary faults in the study area were significantly segmented into four sections:west Shibei1,east Shibei1,west Shibei2 and east Shibei2.Vertically,the faulting initiated during the deposition of Ek to Es4 ,and then went through two cycles of enhanced and subdued stages during the deposi-tion of Es3 ,Es1+2 ,Ed3 , and Ed2 ,and finally inactivated during the deposition of Ed1 .Laterally,the boundary faulting was characterized by being intensive in the central part but weak at both ends during the same geological period.From a space angle,faulting activities were successively carrying on at the same location.The differences of boundary faulting controlled the differential rise and fall of basins,resulting in differential erosion in provenances and the formation of various deposi-tion patterns and tectonic transfer zones,which further affected erosion rate of the provenances,subsidence rate,types and distribution of sedimentary facies ,delta extension distance,as well as lithologies in depositional basins.
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