Characters of Two-Component Constitution of Deep-Water Deposit and Classification of Sequence Stratigraphy in the Niger Delta Basin
详细信息
- 责任者：Wang Zhenqi (College of Geoscience ; Yangtze University ; Wuhan 430100 ; China) ; Li Shitao
- 刊名：Acta Geologica Sinica
- 出版年：2013
- 卷期：87(8)
- 关键词：沉积体系域 ; depositional system tract ; 沉积序列 ; sedimentary sequence ; 几内亚湾 ; Guinea Gulf
- 页码：p.1149-1157
- 图表：9 illus., 27 refs.
- 分类号：0803
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
Based on bore logs and seismic facies characters,the article establishes five criteria for judging sequence boundary of deep-water setting.The strata of middle-upper Miocene in the Nigeria deep-water setting areas were divided into six third-order sequences,two second-order sequences.According to two-component constitution feature of deep-water depositional cycle,the relation between the deltas and the relative sea-level change in shelf area,this study modified classic threefold division of system tracts into twofold division of system tracts:allogenetic system tract and autogenetic system tract.Allogenetic system tract starts from base level descending to early stage of transgression,and it mainly has gravity current deposits that are composed of mass transport deposits and turbidite fans.Autogenetic systems tract starts from middle-late stage of transgression to base level rising to the highest position,and it mainly deposits pelagic and hemipelagic argillaceous sediments.This study also analyzed controlling factors of sequence stratigraphy development.Comprehensive study shows that many factors such weather condition,seal level change,tectonic lifting,sediments supply,and width of continental shelf jointly determine sequence development of deep-water deposit sequences.