sequence interfaces can be identified through demarcation by well drilling and seismic detection in 3rd member of Shahejie Formation of Huimin depression

of which T7

T6

T4

T3 are believed to be maximum lake flooding plane and T6-1

T4-1

T-3 are discovered to be transitional plane of sedimentary process.Therefore

3rd member of Shahejie Formation can be divided into 3 middle basic level cycles(C3

C2

C1).During C3 period

small-scale of turbidite fans were formed due to intensely deposition of the basin.During C2 period

central uplift belts were formed.In C1 period

wide spread of stable mudstone intervals were developed due to gradually weakening of fault-controlled activities.Litho-hydrocarbon reservoirs might have been developed in Jishan sandbody and in the area of JiangJjiadian on the basis of above sequence analysis.Jishan sandbody was largely formed in the period of C2 cycle

developing in turn turbidite fan sandbodies

delta of twist embankment(offshore underwater fan body)-turbidite fan litho-traps were developed along down-dropped blocks of Xiakou fault.