| DOI: | 10.1306/09131110189
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| Scopus记录号: | 2-s2.0-84861619987
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| 论文题名: | Postavulsion channel evolution: Niger Delta continental slope |
| 作者: | Armitage D.A.; McHargue T.; Fildani A.; Graham S.A.
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| 刊名: | AAPG Bulletin
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| ISSN: | 0149-1773
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| EISSN: | 1558-9503
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| 出版年: | 2012
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| 发表日期: | 2012
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| 卷: | 96, 期:5 | | 起始页码: | 823
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| 结束页码: | 843
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| 语种: | 英语
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| Scopus关键词: | Axial channel
; Channel avulsions
; Channel instabilities
; Continental slope
; Cyclic steps
; Downflow
; Entry point
; Hydrocarbon exploration
; Multiple channels
; Niger Delta
; Potential function
; Sea floor
; Shallow subsurface
; Submarine fans
; Subsurface data
; Turbidity current
; Levees
; Ocean currents
; Sediment transport
; Deposits
; aggradation
; avulsion
; backfill
; channel morphology
; coastal evolution
; coastal morphology
; continental slope
; data set
; hydrocarbon exploration
; levee
; seafloor
; seismic reflection
; submarine fan
; Niger Delta
; Nigeria
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| Scopus学科分类: | Energy
; Earth and Planetary Sciences
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| 英文摘要: | Channel avulsion is fundamental in defining submarine fan morphology yet, as a process, is poorly understood. The postavulsion evolution of five channel-levee systems, documented from both the shallow subsurface and the sea floor, is marked in the early stages by relatively wide axial channel belts containing sinuous channel elements. The axial channel belt in each system narrowed through time in association with levee aggradation, which resulted in increased channel confinement. Of the five systems studied, four avulsed from a radial avulsion node at the mouth of the basin feeder-channel complex, which is the entry point to the basin. Only one avulsion occurred at an avulsion node downflow of the mouth of the feeder-channel complex. The degree of channel instability in three of the four systems before an avulsion event was increased by channelfloor aggradation caused by the backfilling of channel-confined turbidity current deposits. Channel-floor aggradation reduced the confinement relief of the systems, thereby increasing the probability of avulsion during an outsized flow event. The backfilled deposits in the channel belts display relatively high seismic-reflection amplitudes inferred to be coarser grained (more sand rich) than their surroundings, that is, out-of-channel deposits. Overbank cyclic steps are exceptionally well preserved on subsurface levees, and their potential function in promoting an avulsion event is discussed. The actual process of avulsion is caused by the flow itself instead of a reduction in confinement relief, and although outsized flows are the likely trigger, depending on the degree of this relief in the channel, multiple small flows could also be responsible for levee breaching, resulting in avulsion. The process of channel-system evolution resulting in avulsion can be applied to other subsurface data where compensating high-amplitude channel belts are recognized. In the context of hydrocarbon exploration, investigating up depositional dip to identify avulsion nodes increases the chance of locating sand-rich deposits, especially where multiple channels converge on one point. Copyright ©2012. The American Association of Petroleum Geologists. All rights reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861619987&doi=10.1306%2f09131110189&partnerID=40&md5=17480e7f5c212656ecd06fbb3eabb5c6
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/13343
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| Appears in Collections: | 过去全球变化的重建
影响、适应和脆弱性
科学计划与规划
气候变化与战略
全球变化的国际研究计划
气候减缓与适应
气候变化事实与影响
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| Recommended Citation: | |
Armitage D.A.,McHargue T.,Fildani A.,et al. Postavulsion channel evolution: Niger Delta continental slope[J]. AAPG Bulletin,2012-01-01,96(5)
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