Abstract:

Rifting basins in the north part of South China Sea have experienced two evolution stages:rifting stage in the early Tertiary and postrifting stage in the late Tertiary and Quaternary.Due to coupled sedimentation and multistage rifting,the basins were infilled with recyclical tectono stratigraph successions,including a series of source rocks,which constitute more than one petroleum systems.Meanwhile,it is an important process for hydrocarbon accumulation that the remigration and retrap of oil and gas caused by reactivities of fault system.There are three evolution episodics in the rift stage of Zhu Ⅲ subbasin in Pearl River Mouth Basin,in which an event of basin boundary faulting occurred at the end of late Eocene that made the subsidence center migrated,different type of paleolakes developed,multitypes of source rocks and a series petroleum systems formed.Faulting episodic in the postrift stage,however,were closely related to the remigration and retrap of oil and gas.

Key words: rifting, stratigraphic sequence, lakes, petroleum system, hydrocarbon remigration