沾化凹陷孤岛东部斜坡下第三系层序地层学

/ EVOLUTION OF SEQUENCE STRATIGRAPHY IN LOWER TERTIARY ON THE EASTERN SLOPE OF GUDAO ISLAND IN ZHANHUA DEPRESSION

采用层序地层学的划分与对比方法，将沾化凹陷孤岛东部斜坡下第三系划分出２个层序，又将第Ⅰ层序划分为３个准层序组和７个准层序。由于孤岛东斜坡地形较高，低水位体系域和湖侵体系域在该区不发育，因而仅发育高水位体系域。高水位体系域主要由滨浅湖沉积体系、扇三角洲沉积体系和浊积扇沉积体系组成。其中，扇三角洲和浊积扇砂体构成了本区的主要储层类型。

The lower Tertiary on eastern slope of Gudao island in Zhanhua depression is divided into two sequences based on sequence stratigraphy. The first sequence is subdivided into three parasequence sets and seven parasequences. Because the elevation of eastern slope of Gudao island is high, low stand system tract and transgressive system tract are not developed in this area instead of high stand system tract. High stand system tract is composed of coast and shallow lake sedimentary system, fan delta sedimentary system and turbidite fan sedimentary system. Among them the fan dalta sedimentary system and the turbidite fan sedimentary system are the main sedimentary body in this area. The identification mark, the sedimertary model and the characteristics of sandbody distribution are summarized.