Abstract:

According to the high-resolusion sequence stratigraphy theory and method, the Dongying strata in the Liaozhong Sag has been divided into three 3rd order sequences and six 4th order sequences based on the integrated
study on cores, well logs, cryptogam and seismic data. Several kinds of depositional systems have been identified,such as alluvial fan /fan delta deposits, fluvial and delta deposits, incised valley filling, sea-gull deposit, floodingm basin deposit, lacustrine deposit, gravity or turbidity flow deposit, and so on. The best favorable sequence place for lithology exploration such as turbidity system and subsea apron are identified based on the complication of the 4th order sequence. The position is the bottom of the 4th order sequence and the top of the 3rd order sequence of SQd2 and SQd3. Through the analysis of the characteristics and positions of the depositional system, it can be concluded that the types and position of the depositional system are controlled by palaeostructure and palaeoclimate.

Key words: palaeogeomorphology, high resolution sequence stratigraphy, depositional system, Dongying Formation, Palaeogene