东海西湖凹陷花港组层序划分

大部分学者将东海西湖凹陷花港组划分为两个三级层序,但其层序界面与构造运动、古气候等重大地质事件之间在时间上不十分协调。本文以经典层序地层学、地震地层学为理论指导,在岩电特征、古生物特征、地震相分析等方面研究的基础上,结合全球性构造运动、海平面变化及古气候研究,重新厘定了东海西湖凹陷古近系花港组层序。在花港组识别出两个二级层序界面和两个三级层序界面,将花港组划分为3个三级层序。本研究对东海西湖凹陷层序地层的研究具有重要意义,同时对精细刻画层序格架内有利储层,指导生产具有积极意义。

Sequence stratigraphic division of the Huagang Formation in the Xihu depression, East China Sea

The Xihu depression lies as a major petroleum depossion in the northwestern part of the East China Sea shelf basin. According to electrical properties,palaeontological fossils,seismic facies,global seal-level changes and palaeoclimatic responses,the Palaeogene Huagang Formation in the Xihu depression,East China Sea may be redivided into two second-order sequence boundaries including SSB4 and SSB5 ,and two third-order sequence boundaries including SB6 and SB5. Correspondingly,three third-order sequences have been distinguished in the Formation,including SQ4,SQ5 and SQ6. This study helps improve our knowledge of the sequence stratigraphic division and the redelineation of favourable hydrocarbon reservoirs within the sequence stratigraphic framework in the study area.