秦南凹陷S-北断裂带古近纪构造活动与沉积作用的耦合关系

COUPLING RELATIONSHIP BETWEEN PALEOGENE TECTONIC ACTIVITIES AND SEDIMENTATION FOR S-NORTH FAULT BELT IN QINNAN SAG

利用三维地震、录井、测井和岩心分析等资料,运用断层活动速率法,分析了秦南凹陷沙三期至东一期S-北断层的活动特征以及边界断层的活动和演化对沉积速率、沉积相、砂体等的影响。研究表明:边界断层在平面上可分为分S-A和S-B两段;纵向上,沙三期—东一期,断层活动整体呈强—弱—强—弱的特点;各地质时期S-A、S-B断层均表现为"强—弱"的变化特点,且断层的两个倾末端活动较弱;断层活动的强弱变化控制盆地的差异沉降,形成了"洼—隆"相间的古地貌格局,进而控制三角洲进积方向和砂体展布规模。

With the help of 3D seismic,well/mud logging and core analysis data,and moreover the method of the fault activities rate,the activities characteristics of S-North Fault of Es3-Ed1 in Qinnan Sag were analyzed,so were the influences of the boundary fault activities and evolution on the deposition rate,depositional facies,sand bodies and so on. The study shows thatthe boundary faults can be divided into two parts on the plane： Interval S-A and SB; vertically,during the deposition of Es3 to Ed1,the fault activities showed the strong-weak-strong-weak features in the whole; both Interval S-A and S-B showed the strong-weak change features in every geological epoch,and moreover the two fault tail activitieswere weak; the strong and weak changes of the fault activities controlled the differential settlement of the basin and furthermore the subsag-and-uplift ancient landform was formed,and then the progradational orientation and sandbody spread laws were also dominated.