Migration-aggradation history and 3-D seismic geomorphology of submarine channels in the Pleistocene Benin-major Canyon, western Niger Delta slope

doi:10.1016/j.marpetgeo.2007.01.005

	Migration-aggradation history and 3-D seismic geomorphology of submarine channels in the Pleistocene Benin-major Canyon, western Niger Delta slope
	Deptuck, Mark E.; Sylvester, Zoltan; Pirmez, Carlos; O'Byrne, Ciaran
刊名	MARINE AND PETROLEUM GEOLOGY
	2007-06-01
卷号	24 期号:6-9 页码:406-433
关键词	submarine channels parameterization geomorphology evolution channel migration aggradation 3-D seismic
ISSN号	0264-8172
DOI	10.1016/j.marpetgeo.2007.01.005
英文摘要	Several laterally offset and aggradational sinuous submarine channels are contained within a 54 km long segment of the Benin-major Canyon. Axial channel deposits produce high amplitude reflections on three-dimensional (3-D) seismic profiles. Some seismic reflections have U- or V-shaped cross-sectional motifs that were correlated with confidence along linear to meandering paths for distances up to 70 km. They are referred to here as channel-forms (CFs), and are believed to be the axial parts of submarine channels preserved during overall channel floor aggradation. A total of 15 separate CFs were mapped allowing thalweg-gradients, dimensions, and morphology to be studied spatially and through time, providing insight into how submarine canyons fill. Their planform geometry evolved predominantly in a stepwise fashion through alternating periods of cut-and-fill, but more gradual channel migrations are also observed. The largest offsets in successive channel floor position occur after periods of significant vertical CF fill (thalweg plugging'-with deposits commonly consisting of lower amplitude, transparent to chaotic seismic reflections). The passage of erosive flows after such periods of fill caused abrupt shifts in channel position, particularly at meander bends, with increased potential for the formation of pseudo meander loop cut-offs. Significant spatial differences in the stacking architecture of CFs are attributed to local slope deformation and perhaps also to a recent channel avulsion just west of the study area. Abrupt channel straightening in the western study area coincides with a period of increased valley-gradient associated with amplification of an underlying anticlinal fold. The youngest CFs in this area show limited aggradation and are characterized by repeated episodes of headward erosion causing knickpoint migration as the recent channel floor tried, unsuccessfully, to establish a smooth graded depth profile. This is in stark contrast to the time-equivalent predominantly aggradational CFs in the eastern study area that show a progressive increase in sinuosity through time. (C) 2007 Elsevier Ltd. All rights reserved.
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000250432100003
内容类型	期刊论文
源URL	[http://ir.fio.com.cn/handle/2SI8HI0U/4568]
专题	自然资源部第一海洋研究所
作者单位	Shell Int Explorat & Prod BV, Turbidite Res Team, Houston, TX USA
推荐引用方式 GB/T 7714	Deptuck, Mark E.,Sylvester, Zoltan,Pirmez, Carlos,et al. Migration-aggradation history and 3-D seismic geomorphology of submarine channels in the Pleistocene Benin-major Canyon, western Niger Delta slope[J]. MARINE AND PETROLEUM GEOLOGY,2007,24(6-9):406-433.
APA	Deptuck, Mark E.,Sylvester, Zoltan,Pirmez, Carlos,&O'Byrne, Ciaran.(2007).Migration-aggradation history and 3-D seismic geomorphology of submarine channels in the Pleistocene Benin-major Canyon, western Niger Delta slope.MARINE AND PETROLEUM GEOLOGY,24(6-9),406-433.
MLA	Deptuck, Mark E.,et al."Migration-aggradation history and 3-D seismic geomorphology of submarine channels in the Pleistocene Benin-major Canyon, western Niger Delta slope".MARINE AND PETROLEUM GEOLOGY 24.6-9(2007):406-433.