Knickpoint migration in submarine channels in response to fold growth, western Niger Delta

Heiniö, Päivi; Davies, Richard J.

doi:10.1016/j.marpetgeo.2006.09.002

Cited by 110 publications

(84 citation statements)

References 38 publications

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“…For example, a channel on the steeper, down-dip side of an anticline will undergo upstream-propagating incision until equilibrium is achieved. Knickpoints probably play an important role in submarine channel incision (Heiniö and Davies, 2007;Sylvester and Covault, 2016). Channel segments affected by ongoing subsidence are likely to respond with deposition.…”

Section: Submarine-channel Stratigraphic Evolutionmentioning

confidence: 99%

The Stratigraphic Record of Submarine-Channel Evolution

Covault¹,

Sylvester²,

Hubbard³

et al. 2016

TSR

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Section: Submarine-channel Stratigraphic Evolutionmentioning

confidence: 99%

The Stratigraphic Record of Submarine-Channel Evolution

Covault¹,

Sylvester²,

Hubbard³

et al. 2016

TSR

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“…Our modeling and field observations suggest that (1) development of sinuosity during incision results in poorly preserved inner bend deposits and hanging cutoffs that are disconnected from the most recent channel thalweg; and (2) steep cutoff-related knickpoints with gradients of 40-100 m/km lead to a significant variability of otherwise smooth submarine channel gradients. In addition to the previously documented knickpoint-generating processes of avulsion (Pirmez et al, 2000) and structural deformation (Heinio and Davies, 2007), cutoff-related knickpoints are probably common features of most submarine channels with high sinuosities. This is a process that is likely to affect both the mor-phology and stratigraphy of submarine channel deposits, without any influence of external fac-tors, as it has the potential to result in incisions several tens of meters deep into already deposited channel sediments.…”

Section: Resultsmentioning

confidence: 87%

“…However, channel slope variability and knickpoint dynamics are likely to be important factors in the long-term evolution of submarine channels (Pirmez et al, 2000;Mitchell, 2006;Heinio and Davies, 2007). Therefore, in a manner similar to that of Finnegan and Dietrich (2011), we track the vertical coordinate of the channel centerline.…”

Section: Numerical Modelingmentioning

confidence: 99%

Development of cutoff-related knickpoints during early evolution of submarine channels

Sylvester¹,

Covault²

2017

Preprint

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Submarine channels are often thought of as having relatively simple geometries, with significant alongchannel morphologic and stratigraphic continuity. Using high-resolution seismic reflection data from offshore Angola and a kinematic model of channel evolution, we present evidence that channels on the seafloor can develop slope variability as a result of meander cutoff events. When cutoffs develop, the shortened flow paths produce locally steep gradients, thus initiating knickpoints. Waves of knickpoint retreat and the related channel incision explain the occurrence of terraces and associated remnant channel deposits above the youngest channel thalweg. The simple processes of meander cutoff followed by knickpoint retreat are intrinsic to submarine channels and result in significant morphologic variability, erosion, and stratigraphic complexity, without any external forcing. These insights highlight the early evolution of submarine channels, a phase with a record that is commonly fragmented or completely absent as a result of subsequent erosion, and allow a better understanding of the autogenic controls on deep-marine stratigraphy.

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“…However, a more likely explanation is that all the knickpoints in the floors of Hatteras Transverse Canyon and lower Hatteras Canyon, which are all up-channel from the large landslide deposits, represent a disruption of the equilibrium profiles of both canyon channels by the landslide deposits, thus elevating the distal-most canyon channels, and that the two channels are presently headward-eroding to re-establish new equilibrium profiles. The flat, featureless nature of the channel floors of both Hatteras Transverse Canyon and lower Hatteras Canyon suggests channel entrenchment during knickpoint retreat has yet to begin (Pirmez et al, 2000;Kneller, 2003;Mitchell, 2004Mitchell, , 2006Holland and Pickup, 1976;Heiniö and Davies, 2007). In addition to the knickpoints in the channel, the head of Hatteras Transverse Canyon and the side channel of upper Hatteras Transverse Canyon also appear to be eroding headward.…”

Section: Discussionmentioning

confidence: 99%

Hatteras Transverse Canyon, Hatteras Outer Ridge and environs of the U.S. Atlantic margin: A view from multibeam bathymetry and backscatter

2016

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Previously unknown features in Hatteras Transverse Canyon and environs were recently mapped during multibeam surveys of almost the entire eastern U.S. Atlantic continental margin. The newly identified features include (1) extensive landslide scarps on the walls of Hatteras Transverse and Hatteras Canyons, (2) an area of multiple landslide deposits that block lower Hatteras Transverse Canyon, (3) a large depositional feature down-canyon from the landslide deposits that rises 100 m above the uppermost Hatteras Fan and has buried the transition from the mouth of Hatteras Transverse Canyon to uppermost Hatteras Fan, (4) a zone of cyclic steps on upper Hatteras Fan that suggests supercritical turbidity currents performed a series of hydraulic jumps and formed large upstream-migrating bedforms, (5) several knickpoints in the channel thalwegs of both Hatteras Transverse Canyon and Hatteras Canyon, one 40 m high, that suggest both canyon channels are out of equilibrium and are in the process of readjusting, either to the channel blockage by the extensive landslide deposits or by a readjustments to increased sedimentation during the last eustatic lowstand, (6) a large area of outcrop on the lower margin between Pamlico and Hatteras Canyons that previously was interpreted as an area of slumps, blocky slide debris and mud waves, (7) headward erosion in the head region of Hatteras Transverse Canyon where it has intercepted the lowest reaches of Albemarle Canyon channel as well as headward erosion in a small side channel that has eroded into Hatteras Outer Ridge and (8) sections of bedforms on Hatteras Outer Ridge that are partially buried by sediment from Washington-Norfolk Canyon channel as well as by sediment transported from Hatteras Abyssal Plain. The newly discovered features add a new level of detail to understand the recent processes that have profoundly affected Hatteras Transverse Canyon, Hatteras Canyon and, to a lesser degree, Hatteras Outer Ridge.

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Knickpoint migration in submarine channels in response to fold growth, western Niger Delta

Cited by 110 publications

References 38 publications

The Stratigraphic Record of Submarine-Channel Evolution

The Stratigraphic Record of Submarine-Channel Evolution

Development of cutoff-related knickpoints during early evolution of submarine channels

Hatteras Transverse Canyon, Hatteras Outer Ridge and environs of the U.S. Atlantic margin: A view from multibeam bathymetry and backscatter

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