Fault Systems And Their Controlling Effect On Evolution And Formation Of Buried Hill In Tanan Depression

The fractural structure and basin structure features is researched on the base of the explanation of regional seismic profiles,then combining basin subsidence history,the formation and process of evolution of basin,and its dynamics pattern is dealed with by means of analyzing basin deformation sequence and constructing different stage of tectonic strain field features,and then controlling effect on evolution of buried hill is revealed.Tanan depression is a negative secondary tectonic unit located in the south of the central fault depression belt in Hailar-Tamuchage basin.It's a dustpan fault depression basin with steep dip angle in the east limb and gentle in the west,and it is controlled by three NE trending main trunk faults and develops three tectonic belts in the western?central and eastern.We define tectonic framework in Tanan depression and divide structure unit and stockwerke.Though analyzing fault systems,we confirm the character?attitude?density?development model and array model of fault systems.we also define that there are two phases structural deformation in Tanan depression fault systems,that is to say:base rock deposition laterally and Yimin Formation last stage.They are Separately development formation of basement rift and faulted activity period;The tectonic evolution profile indicates evolution and formation of fault Successively udergo extensional deformation from Tongbomiao formation to Damoguanghe formation;Yimin formation mainly happen strike-slip deformation,Qingyungang formation mainly genesis inversion structure deformation,there are different deformation characteristic in the different time for faults.By comprehensive utilization of seismic and drilling data,fault systems,genetic types and distribution laws of buried hills were studied.It was considered that early-extended,mid-strike-slip fault system and early-extended,mid-strike slip and late reversed fault system not only controlled the formation of buried hill,but also were major pathways for oil migrating to buried hill.Syngenetic buried hill is main genetic type of basement buried hill in Tanan depression.Paleogeomorphic hills and epigenetic buried hills are not developed.Buried hills are mainly distributed in the western and central tectonic belt.