Abstract:

According to analyses of rock component，element geochem istry and sandy net-to-gross ratio，two provenance systems，namely the southern one and the northeastern one，are believed to exist during the sedimentaˉtion of the upper4 th member ofEocene Shahejie Formation（Es 4 ）in Guangli area ofDongying Sag，the BohaiBay Basin and they controlled the genetic types and distribution of sandbodies.In the early period of the sedimentation of the upperEs 4 ，the south provenance predom inated，and there developed meander river delta and shallow lake-beach bars.While in the late period the sedimentation of the upperEs 4 ，the northeast provenance predom inated，and there developed braided river delta and fan delta.In the m iddle period of the sedimentation of the upperEs 4 ，the two provenance systems coexisted，and there developed sandbodies ofmultiple genetic typeswith alternating gravity flow deposits and traction currentdeposits.Beach bars resulted from modification of longshore current at the delta front should be important targets for further exploration.Exploration of lithologic structural combination traps of beach bars types should be strengthened.

Key words: Shehejie Formation, provenance system, sedimentary system, Guangli area, Dongying Sag, BohaiBay Basin