| Yitong Graben is the south part of Jia-Yi Graben which is great in length / width, being a continental stride-slip full apart basin bounded by faults. The episodic activities of tectonics were strong, the degrees of subsidence were different, and the sedimentations were complex with the point source areas and the paleo-geography of interplaced lakes and fans during the basin evolution. At present, some problems influenced the development of petroleum exploration are dividing and correlation of chronological stratigraphy, sequence stratigraphy and non structural oil traps. Those are focused in this paper to serve the petroleum exploration, specially in litho-straral traps.The interior architectures, structural units, sedimentary fillings of Yitong Graben were controlled strictly by faulting, and the study of structural-sedimentary evolution is a basic work of the analysis of sequence stratigraphy. The key controlling fault is a stride-slip one steeply located in northwestern margin, having complicated changing histories in activity patterns and mechanism during the forming and evolution of the graben. The boundary faults in the southeastern margin were associate faults which had different patterns due to the basement lithography and mechanism. The evolution of the graben had 6 stages that were initial rifting, right-rotation extensional-wresting, lift-rotation extensional-strip-slipping, right-rotation shearing, transverse faulting and thrusting.Under the guidance of modern sedimentology, some sedimentary facies are recognized, including alluvial fan, delta, lucastrine, sub-water fan and fluvial ect., through the integrated study of drilling, logging and seismic facies. The depositional systems developed during Paleocene were follow : (1) alluvial-fluvial-fan delta-lake (sub-water fan) system in lowstand systems tract, (2) fan (braid stream) delta-lake (sub-water fan)system in transgressive and highstand systems tract, (3) lake ( sub- water fan) with on source supplying (lake bay), (4) fluvial system during the ending of the basin. The evolution model and sedimentary filling sequence are set up by analysis the paleo-geography, giving a dividing standard of interior units in a sequence and the recognizing marks of sequence boundaries. The sedimentary covers are divided into 10 sequences ofâ…¢rank in study area, 7 of the sequence (from sequence 1 to sequence 7)and 21 systems tracts are analyzed, as well as dealing with the relationship between sequence boundaries and the traditional surfaces.Sequence1 is Shuang1 member, Sequence 2 is Shuang2 member, Shuang3 member and lower part of Sheling formation, Sequence 3 is the upper part of Sheling formation, Sequence 4 is Yong1 member, Sequence 5 is Yong2 member, Sequence 6 is Yong3 member and Yong4 member, Sequence 7 is Wan1 member, Sequence 8 is Wan2 member and Wan3 member, Sequence 9 is Qijia formation, and Sequence 10 is Chaluhe formation.The girding of seismic profiles with drills being as framwork to control the strata distribution of the graben, the interpretation of seismic sequence stratigraphy is started with 3D space in different structural units and different locations in the same unit, while the dividing and correlation of high resolution of sequence stratigraphy is started in selected drilling wells sections corresponding with related the seismic profiles using the results of high resolution of sequence stratigraphy in single wells. The reasonable chronological stratigraphic framework is set up using integration of drilling and seimic data to compare and test.The developing model of sequence stratigraphy is special, due to the special tectonic background of Yitong Graben. The model of the deep depression zone in the northwestern margin of the graben is different from that of other continental fault basins both in homeland and oversea, while the model of the fault slope in the southeastern margin of the graben is familiar to that of steep slope of half graben developed in other basin in our country. This developing model of sequence stratigraphy of continental basin is one of asymmetry, both sides'faulting and linearity, in high light of tectonic subsidence and lithography as influences on the development of sequence stratigraphy through dividing and correlation of sequence stratigraphy and analysis of key controlling factors. The integrated sequence is composed of LST, TST and HST.The favorable oil bearing sequences is sequence1,2,3 in Danan depression and sequence 3,5,6 in Xinanbao depression, by the associations of source, reservoir and cover rocks and analysis of oil bearing. LST is important litho-stratal trap locations, developed mainly in the transitional zone between depression and uplift. The sand bodies of sub- water fan and fan delta occurred richly in northwestern margin, led to possibility of litho-fault trap in the hangingwall of growth fault. The deep cut valleys and LST fans occurred during LST, the sub-water fan and fan (braid) delta occurred during TST and HST might litho oil trap, upward tinning stratal trap, unconformity trap as well as complex trap. There are 7 favorable exploration zones in Dnan and Xinanbao depressions.
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