A model of submarine channel-levee evolution based on channel trajectories: Implications for stratigraphic architecture

Sylvester, Zoltán; Pirmez, Carlos; Cantelli, Alessandro

doi:10.1016/j.marpetgeo.2010.05.012

Cited by 186 publications

(145 citation statements)

References 56 publications

Supporting

Mentioning

140

Contrasting

Unclassified

Order By: Relevance

“…This observation is consistent with previous studies, which have shown that valley base is a diachronous surface or a composite erosional surface shaped by multiple erosional events (e.g. Deptuck et al, 2003;Sylvester et al, 2011;Kolla et al, 2012;Thomas and Bodin, 2013;Macauley and Hubbard, 2013;Bain and Hubbard, 2016;Di Celma et al, 2011).…”

Section: Possible Causes For Variations In Channel and Valley Morphologysupporting

confidence: 93%

“…Multiple channel forms are identified at the valley base and show the trajectory of lateral channel migrations (Figs. 13c and d) to be consistent with observations in Deptuck et al (2003) and with models proposed by Sylvester et al (2011). Moderate-to highamplitude, parallel reflections are observed above basal lags (Figs.…”

Section: Variations In Valley Morphologysupporting

confidence: 89%

See 1 more Smart Citation

Quantitative seismic geomorphology of a submarine channel system in SE Brazil (Espírito Santo Basin): Scale comparison with other submarine channel systems

Qin

Alves

Constantine

et al. 2016

Marine and Petroleum Geology

View full text Add to dashboard Cite

Detailed morphological analyses of a Pleistocene-Holocene submarine channel system in terms of its hierarchical framework, were carried out using a 3D seismic volume from offshore Espírito Santo, SE Brazil. The channel morphology shows marked variations, with five segments (Segments a to e) being identified along its full length. For example, the cross-sectional area of the channel decreases by a factor of 70 from Segment a to Segment c, and is then followed by a nearly four-fold increase from Segment c to Segment d. The significant changes in channel morphology relate to temporal and spatial variations in flow volume within the channel. In the same channel system, the valley reveals three distinct segments (Segments A to C), with similar aspect ratios but marked variations in morphology along the valley distance. Valley morphological changes are chiefly affected by erosional processes. Segment B is characterised by the largest valley-base width, valley width, and cross-sectional area compared to the other two segments. Valley enlargement in Segment B results from relatively high degrees of lateral channel migration and associated cut bank erosion, leading to the widening of the valley, especially the valley base. In Segment C, the valley is characterised by inner bank erosion in the form of shallow-seated mass failures, which only enlarged the upper part of the valley wall. The spatial variations in both channel and valley morphology documented here suggest an important role of local factors (e.g. salt diapirs, tributaries, overbank collapse) in the development of channel systems. Hence, the morphological analyses developed in this work provide an effective tool for studying channels and valleys on continental slopes around the world.

show abstract

Section: Possible Causes For Variations In Channel and Valley Morphologysupporting

confidence: 93%

Section: Variations In Valley Morphologysupporting

confidence: 89%

Quantitative seismic geomorphology of a submarine channel system in SE Brazil (Espírito Santo Basin): Scale comparison with other submarine channel systems

Qin

Alves

Constantine

et al. 2016

Marine and Petroleum Geology

View full text Add to dashboard Cite

show abstract

“…Are crescentic bedforms in the field typically associated with cyclic hydraulic jumps, and if so, which is the cause FIG. 8.-A) Schematic summary of patterns of erosion and deposition in a vertical section across a submarine channel, from Sylvester et al (2011). It shows why geomorphic surfaces (i.e., the seafloor at various times) may differ from the stratigraphic surfaces finally preserved in the rock record and subsurface seismic reflectors.…”

Section: (B) Supercritical-flow Dynamics and Depositsmentioning

confidence: 99%

Key Future Directions For Research On Turbidity Currents and Their Deposits

Talling

Allin

Armitage

et al. 2015

Journal of Sedimentary Research

165

117

View full text Add to dashboard Cite

Turbidity currents, and other types of submarine sediment density flow, redistribute more sediment across the surface of the Earth than any other sediment flow process, yet their sediment concentration has never been measured directly in the deep ocean. The deposits of these flows are of societal importance as imperfect records of past earthquakes and tsunamogenic landslides and as the reservoir rocks for many deep-water petroleum accumulations. Key future research directions on these flows and their deposits were identified at an informal workshop in September 2013. This contribution summarizes conclusions from that workshop, and engages the wider community in this debate. International efforts are needed for an initiative to monitor and understand a series of test sites where flows occur frequently, which needs coordination to optimize sharing of equipment and interpretation of data. Direct monitoring observations should be combined with cores and seismic data to link flow and deposit character, whilst experimental and numerical models play a key role in understanding field observations. Such an initiative may be timely and feasible, due to recent technological advances in monitoring sensors, moorings, and autonomous data recovery. This is illustrated here by recently collected data from the Squamish River delta, Monterey Canyon, Congo Canyon, and offshore SE Taiwan. A series of other key topics are then highlighted. Theoretical considerations suggest that supercritical flows may often occur on gradients of greater than , 0.6u. Trains of up-slope-migrating bedforms have recently been mapped in a wide range of marine and freshwater settings. They may result from repeated hydraulic jumps in supercritical flows, and dense (greater than approximately 10% volume) near-bed layers may need to be invoked to explain transport of heavy (25 to 1,000 kg) blocks. Future work needs to understand how sediment is transported in these bedforms, the internal structure and preservation potential of their deposits, and their use in facies prediction. Turbulence damping may be widespread and commonplace in submarine sediment density flows, particularly as flows decelerate, because it can occur at low (, 0.1%) volume concentrations. This could have important implications for flow evolution and deposit geometries. Better quantitative constraints are needed on what controls flow capacity and competence, together with improved constraints on bed erosion and sediment resuspension. Recent advances in understanding dilute or mainly saline flows in submarine channels should be extended to explore how flow behavior changes as sediment concentrations increase. The petroleum industry requires predictive models of longer-term channel system behavior and resulting deposit architecture, and for these purposes it is important to distinguish between geomorphic and stratigraphic surfaces

show abstract

“…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. It also might be one of the reasons why the stratigraphic architecture of submarine channel deposits is significantly more complicated than implied by simple stratigraphic models assuming constant along-chan-nel slope (e.g., Sylvester et al, 2011).…”

Section: Discussionmentioning

confidence: 99%

“…The channel centerlines generated with the HK model provide the framework for our simulations. To examine the resulting geomorphology we created geomorphic surfaces that mimic realistic channel morphologies at each time step (e.g., Sylvester et al, 2011). To simulate erosion, we used a cross section with a quadratic shape; then coarse-grained channel deposition is modeled with partially filling the channel to a fraction of the channel depth (Fig.…”

Section: Numerical Modelingmentioning

confidence: 99%

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

Sylvester¹,

Covault²

2017

Preprint

View full text Add to dashboard Cite

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.

show abstract

A model of submarine channel-levee evolution based on channel trajectories: Implications for stratigraphic architecture

Cited by 186 publications

References 56 publications

Quantitative seismic geomorphology of a submarine channel system in SE Brazil (Espírito Santo Basin): Scale comparison with other submarine channel systems

Quantitative seismic geomorphology of a submarine channel system in SE Brazil (Espírito Santo Basin): Scale comparison with other submarine channel systems

Key Future Directions For Research On Turbidity Currents and Their Deposits

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

Contact Info

Product

Resources

About