济阳坳陷下第三系湖相沉积的层序地层学分析

本文按照层序地层学原理,应用多种资料,分析了济阳坳陷地震T2,T6际准层的层序地层学意义,将济阳坳陷下第三系划分成3个二级层序,其中又可以划分出多个三级层序。每个二级层序都可以分成3个体系域:低水位体系域（LST）以盐（膏）岩或灰色泥岩,碳酸盐岩沉积为主;水进体系域（TST）以大套暗色泥岩沉积为特征;高水位体系域（HST）对应于河流 三角洲沉积。湖水面升降与构造运动,古气候及全球性海平面变化有关。3次大的水进期形成的暗色泥岩是主要生油层。低水位近岸（水下）扇、斜坡碳酸盐岩、与三角洲有关的各类砂体是良好的油气储层。层序地层学原理可以应用于湖相沉积。

SEQUENCE STRATIGRAPHIC ANALYSIS OF EOGENE SYSTEM LACUSTRINE DEPOSIT IN JIYANG DEPRESSION

According to the principle of sequence stratigraphy and usable data, the sequence stratigraphic significations of the T2, T, reflection marker-beds in Jiyang depression are discussed in this paper. The lower Tertiary in Jiyang depression may be divided into three second-order sequences, and also be subdivided further into several third-order sequences. Every second-order sequence can be divided into three system tract. Lowstand system tract (LST) mostly consists of salt (gypsum) rock or grey mudstone and carbonate deposition, the strata of the Transgressive system tract (TST) are characterized by the large dark mudstone. The strata of the highstand system tract (HST) correspond to the fluvial-deltaic deposit. The change of the water level in the lake is considered to have close relationship with the tectonic movement, paleoclimate and eustatic cycle. Dark mudstone deposited in three periods of transgression is major source rock. A coastal sand body of submerged fan, a carbonate deposited on the slope on LST, and every sandstone related to the delta deposit is a good reservoir. The principle of sequence stratigraphy can be used in lacustrine deposit.