SEDIMENTARY CYCLES AND DEPOSITIONAL SYSTEMS OF SUBMEMBER Es^3(3～4)IN THE QIANLIYUAN SUBDEPRESSION OF THE DONGPU SAG

In the Submember Es^3(3～4) of Qianliyuan Subdepression,sedimentary cycles reflecting lake transgression-lake regression are well-developed.This kind of cyclic sequences can be trsced and correlated in the studied area.Especially,they have better traceability and contrastability on high resolution seismic profiles.The major factors controlling the cyclic development are the lake-level fluctuation induced by tectonic action and climatic changes in the area.The cyclic sequences may correspond to the fourth-fifth order cycles of global climatic changes.The depositional systems developed in the area mainly include deltaic system,lakebed fan system and deep-bathyal lake system.The fluctuation of lake levels show obvious controls on the formation and development of these depositional systems.