Based on 3-D seismic

drilling data and other data

and by using the theories and methods of high-accuracy sequence stratigraphy

sequence stratigraphic framework has been established in Zhanhua depression

which consists of 1 first-order sequence

4 second-order sequences

17 third-order sequences

51 system tracts

70 parasequence sets and 109 parasequences.Critical surfaces

such as sequence boundary

initial flooding surface and maximum flooding surface

have been defined on seismic profiles

according to the termination patterns of reflection configuration

transformation of stacking patterns of parasequence sets and lithologic profile.Sedimentary systems are categorized and restored based on the stacking pattern of parasequence sets and seismic phases.In the sequence stratigraphic framework

lowstand system tract (LST) consists of many types of sedimentary systems

which are characterized by alluvial fan-fan delta (delta)-lowstand wedge-lowstand fan under control of the third-order slope break.The sedimentary systems in transgression system tract and high stand system tract have inheritance.Combinations of sedimentary systems in each system tract have genetic continuity.Areas where sedimentary systems developed during strong fault subsidence and allocated with unconformities and fault planes are the favorable exploration play.