Abstract：Guan depression is a half graben-like basin whose north side is faulted and south side overlapped.In early Tertiary,the north Daxing fault grew rapidly,and the south Niutuozhen rise uplifted gradually,These geological factors made slant the newly formed formations in the depression.Then the dominant gravity action caused various gravity slumping structures in the depression.There are rollover strures and fault terraces along the Daxing fault,and along slope of the Niutuozhen rise there occur tensional faults and associated faults dipping against the slope,These gravity slumping structures occurred before hydrocarbon migration,so they are favourable places for hydrocarbon accumulation.
