摘要
东非海岸盆地深水区的研究主要集中在油气富集的深部地层,缺乏对第四系深水沉积的研究。文中利用二维地震资料,对东非坦桑尼亚和鲁伍马盆地第四系深水区的深水沉积开展研究,查明了沉积类型,划分了沉积单元,对深水沉积建立了沉积模式。研究表明:1)研究区发育深水重力流沉积、等深流沉积、等深流与重力流交互作用沉积,分为峡谷、水道、漂积体及块状搬运复合体4种沉积单元。2)研究区深水沉积由北至南差异明显,坦中地区深水沉积规模较大,主要发育重力流水道及丘状漂积体;坦南地区发育峡谷,深水沉积规模整体较小;鲁北地区深水沉积规模较大,发育有峡谷、水道及席状漂积体。3)海底地形的差异导致坦中地区的重力流能量较弱,坦南地区和鲁北地区的重力流能量较强;在海底地貌的限制下,等深流沉积在坦中地区形成丘状漂积体,在鲁北地区形成席状漂积体;坦中南部的等深流与重力流发生交互作用,发育向南迁移的侧向迁移水道。
The reserach on the deep-water area of the East African coastal basins mainly focuses on the deep strata with rich oil and gas ennrichment,and there is a lack of research on the Quaternary deep-water deposition.In this study,2D seismic data is used to study the deep-water deposition in Quaternary deep-water areas of Tanzania and Ruvuma Basin in East Africa.The sedimentary types are identified,the sedimentary units are divided,and the sedimentary model of deep-water deposition is established.The research shows that:(1)Deep-water gravity flow deposition,contour flow deposition and contour-gravity flow interaction deposition are developed in the study area,which are divided into four types of sedimentary units,namely canyon,channel,drifts and mass-transport composites.(2)The deep-water deposition in the study area displays obvious differences from north to south.The deep-water deposition in central Tanzania is large in scale,mainly developing gravity flow channels and mound-shaped drifts.Southern Tanzania has obvious canyon development,and has small-scale deep-water deposition overall.The deep-water deposition in northern Ruvuma is relatively large in scale,with canyons,channels and sheet-shaped drifts developed.(3)Due to the difference of submarine topography,the gravity flow energy of central Tanzania is relatively weak,while the gravity flow energy of southern Tanzania and northern Ruvuma are relatively strong.Limited by submarine geomorphology,contour flow deposition forms mound-shaped drifts in central Tanzania and sheet-shaped drifts in northern Ruvuma.The interaction between contour flow and gravity flow occurs in the south of central Tanzania,and lateral-migrating channels migrating southward are developed.
作者
于星
赵红岩
邱春光
何幼斌
李华
YU Xing;ZHAO Hongyan;QIU Chunguang;HE Youbin;LI Hua(School of Geosciences,Yangtze University,Wuhan 430100,China;CNOOC International Company Limited,Beijing 100028,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2024年第2期257-265,共9页
Fault-Block Oil & Gas Field
基金
国家自然科学基金项目“内蒙古乌海地区奥陶系深水复合型及迁移型重力流水道形成机理”(42272115)、“鄂尔多斯盆地西南缘中—上奥陶统深水斜坡-海槽区等深流-重力流混合沉积形成机理”(42272113)
“十三五”国家科技重大专项专题“东非海岸重点盆地勘探潜力综合评价”(2017ZX05032-002-003)。
关键词
深水沉积
重力流
等深流
交互作用
第四系
东非海岸
deep-water deposition
gravity flow
contour flow
interaction
Quaternary
East Africa coast
作者简介
第一作者:于星,男,1998年生,在读硕士研究生,主要从事深水沉积学方面的研究。E-mail:2816477208@qq.com。;通信作者:李华,男,1984年生,副教授,主要从事沉积学研究。E-mail:501026@yangtzeu.edu.cn。
