辽中凹陷东营组高精度层序地层及沉积体系

应用高精度层序地层学的理论和方法，以岩芯、测井资料、孢粉和地震资料为基础建立了辽中凹陷古近系东营组高精度层序地层格架，划分出 3 个三级层序和 6 个四级层序。四级层序内识别出冲积扇、扇三角洲、曲流河三角洲、辫状河三角洲、下切水道、滨浅湖、深湖浊积、重力流等多种沉积体系。在高精度的四级层序编图基础上识别出有利于岩性圈闭勘探的浊积体系和水下扇体系的层序发育部位，SQd2 上部的四级层序和 SQd3 上部的四级层序底部均是隐蔽圈闭发育的有利部位。通过层序格架内各沉积体系的发育特征和位置，总结出沉积体系的发育类型和在凹陷中的位置明显受到古构造和古气候双重因素地控制。

THE CHARACTERISTICS OF SEQUENCE STRATIGRAPHY AND DEPOSITIONAL SYS-TEMS OF THE PALAEOGENE DONGYING FORMATION IN LIAOZHONG SAG

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 integratedstudy 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.