Migrated hybrid turbidite-contourite channel-lobe complex of the late Eocene Rovuma Basin, East Africa

IOCAS-IR

	Migrated hybrid turbidite-contourite channel-lobe complex of the late Eocene Rovuma Basin, East Africa
	Yintao Lu; Xiwu Luan ; Boqing Shi ; Weimin Ran ; Fuliang Lü ; Xiujuan Wang ; Quanbin Cao ; Xiaoyong Xu ; Hui Sun; Genshun Yao
发表期刊	Acta Oceanologica Sinica
ISSN	0253-505X
	2021-02-15
出版年	2021
卷号	v.40 期号:02 页码:85-98
文献类型	CNKI期刊论文
摘要	Analysis of 3 D seismic data and well log data from the Rovuma Basin in East Africa reveals the presence of a late Eocene channel-lobe complex on its slope. The first two channels, denoted as channel-1 and channel-2, are initiated within a topographic low on the slope but come to a premature end when they are blocked by a topographic high in the northwest region of the basin. New channels migrate southeastward from channel-1 to channel-6 due to the region's sufficient sediment supply and stripping caused by bottom currents. The primary factors controlling the development of the channel complex include its initial paleo-topographic of seafloor, the property of gravity flows, the direction of the bottom current, and the stacking and expansion of its levees. The transition zone from channel to lobe can also be clearly identified from seismic sections by its pond-shaped structure. At a certain point, thest systems record a transiton from erosive features to sedimentary features, and record a transition from a confined environment to an open environment. Channels and lobes can be differentiated by their morphologies: thick slump-debris flows are partly developed under channel sand sheets,whereas these slump-debris flows are not very well developed in lobes. Well log responses also record different characteristics between channels and lobes. The interpreted shale volume throughout the main channel records a box-shaped curve, thereby implying that confined channel complexes record high energy currents and abundant sand supply, whereas the interpreted shale volume throughout the lobe records an upward-fining shape curve,thereby indicating the presence of a reduced-energy current in a relatively open environment. Within the Rovuma Basin of East Africa, the average width of the Rovuma shelf is less than 10 km, the width of the slope is only approximately 40 km, and the slope gradient is 2°–4°. Due to this steep slope gradient, the sand-rich top sheet within the channel also likely contributes to the straight feature of the channel system. It is currently unclear whether the bottom current has any effect on its sinuosity.
关键词	East Africa Rovuma Basin deep-water sediment channel-lobe complex
CNKI专辑号	A;
CNKI专辑名称	基础科学;
CNKI专题号	A010;A011;
CNKI专题名称	海洋学;地质学;
分类号	P736.21
收录类别	中科院核心 ; 中科院扩展
语种	英文;
资助项目(基金）	The China-ASEAN Maritime Cooperation Fund Project under contract No. 12120100500017001 ; the National Natural Science Foundation of China under contract Nos 42076219, 92055211 and 42006067
文献类型	CNKI期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/187864
专题	中国科学院海洋研究所
作者单位	1.PetroChinaHangzhouResearchInstituteofGeology 2.QingdaoInstituteofMarineGeology,ChinaGeologicalSurvey 3.LaboratoryofMarineMineralResources,PilotNationalLaboratoryforMarineScienceandTechnology(Qingdao) 4.ChinaNationalOilandGasExplorationandDevelopmentCorporation 5.InstituteofOceanology,ChineseAcademyofSciences
推荐引用方式 GB/T 7714	Yintao Lu,Xiwu Luan,Boqing Shi,et al. Migrated hybrid turbidite-contourite channel-lobe complex of the late Eocene Rovuma Basin, East Africa. 2021.