The Architecture of Turbidite Slope Channels

Mayall, Mike; Stewart, Ian

doi:10.5724/gcs.00.15.0578

Cited by 107 publications

(121 citation statements)

References 0 publications

Supporting

Mentioning

108

Contrasting

Order By: Relevance

“…Meander cut-offs are a common phenomenon in highly sinuous, laterally migrating channel belts and erosional channel belts (or erosional channel fairways) (Cronin et al, 2013Deptuck et al, 2003;Janocko et al, 2013;Kolla et al, 2001;Mayall and Stewart, 2000;McHargue, 1991;O'Connell et al, 1995;Samuel et al, 2003). Meander cut-offs in fluvial systems are formed where the progressive accentuation of bend curvature results in neck or chute cut-offs during river floods and the formation of oxbow lakes.…”

Section: Meander Cut-offsmentioning

confidence: 97%

See 1 more Smart Citation

Genesis and character of thin-bedded turbidites associated with submarine channels

Hansen

Callow

Kane

et al. 2015

Marine and Petroleum Geology

112

129

View full text Add to dashboard Cite

Submarine channel related thin-bedded turbidites are deposited in environments such as external levees, internal levees, depositional terraces and at times of channel abandonment.Thin-bedded turbidites are defined as beds that are less than 10cm thick, but the described environments can at times contain beds up to 50cm thick which would be classified as medium or thick-bedded (Boggs, 2006). This paper addresses many examples of these environments from the modern seafloor, outcrop and the subsurface to suggest criteria that assist in the differentiation of levees and terraces from an architectural, sedimentological, M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 ichnological and hydrocarbon reservoir perspective. External levees confine channel belts and are elongate sedimentary deposits that are a product of over-spill of turbidity currents from the channel belt they confine. External levees often have predictable vertical, lateral and downstream changes but can commonly be modified by collapse of the inner external levee into the channel, collapse on the outer external levee, sediment waves, and interaction of external levees with topographic features such as other channels, other external levees, basin margins or previous slump/slide blocks, which can greatly modify the sand distribution within them.A combination of internal levees, depositional terraces and slide blocks of external levee sediment make up thin-bedded turbidites within channel belts. We differentiate between wedge shaped internal levees and topographically flat or subdued depositional terraces whose differing geometries and sand distribution reflect the fact that the flow processes involved in the formation of these deposits are different. The characteristic wedge shape of an internal levee requires sufficient space within the channel belt for the over-spilling current to decelerate and deposit the majority of its suspended sediment before reaching the bounding topography of the channel belt. In the case of depositional terraces the space available in the channel belt is insufficient for the current to deposit the majority of its sediment before reaching the bounding topography of the channel belt, creating confined sheet-like deposits.External levees, internal levees and depositional terraces have distinct sedimentological characteristics such as sand bed thickness trends and sedimentary structures that can be used to distinguish them. Together with sedimentological characteristics, in some systems these thin-bedded turbidite deposits contain distinctive trace fossil assemblages, where channel proximal deposits such as proximal external levees, internal levees and depositional terraces M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 3 can have much higher biodiversity than sand-rich channel axes and more mud-dominated outer external levees.The depositional sites for internal levees and depositional terraces within channel belts can be formed by various processes such as entrenchment, point bar accretion, meander bend cutoff, ...

show abstract

Section: Meander Cut-offsmentioning

confidence: 97%

“…resulting in a variety of aggradational channel-fills (Kneller, 2003;Mayall and Stewart, 2000;McHargue et al, 2010;Samuel et al, 2003).…”

Section: Allogenic Controlsmentioning

confidence: 99%

Genesis and character of thin-bedded turbidites associated with submarine channels

Hansen

Callow

Kane

et al. 2015

Marine and Petroleum Geology

112

129

View full text Add to dashboard Cite

show abstract

“…Submarine channels are major conduits for sediment transported from continental shelves to abyssal plains, and their deposits comprise important reservoirs in deep-water basins when filled with sand-or silt-prone sequences (Mayall and Stewart, 2000;Mayall et al, 2006;Wynn et al, 2007). To better organize and compare architectural elements associated with submarine channels, several hierarchical frameworks have been proposed in the literature (Gardner and Borer, 2000;Campion et al, 2000;Sprague et al, 2002Sprague et al, , 2005.…”

Section: Introductionmentioning

confidence: 99%

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

“…Sandy, bedded deposits overlie the MTC, with a general tendency for increasingly meandering internal channel-fills in the upper section. A similar channel-fill succession is reported from offshore West Africa (Mayall & Stewart 2000). However the high-resolution internal fill style also reflects sequence hierarchy and the type of sediment available at the shelf edge.…”

Section: Canyons and Channelsmentioning

confidence: 69%

Submarine slope systems: processes and products

Flint

Hodgson

2005

View full text Add to dashboard Cite

Abstract:Understanding of the processes operating on submarine slopes, the preserved depositional products and post-depositional modifications to sediment body geometries through instability and remobilization requires integration of data from modern slopes with information derived from seismic and outcrop studies of ancient slope successions. Although local factors are important, key generic concepts that aid in predicting submarine slope processes and products include: (1) shelf accommodation/lateral sediment supply variations on sediment delivery; (2) the spatial/temporal distribution of characteristic styles/intensities of sediment instability and remobilization; and (3) a generalized model for the stratigraphic development of slope channel complexes, slope fans and the temporal relationships between these major components of slope stratigraphy.Key remaining problems include bridging the gap between the timescales sampled by Recent to late Quaternary studies and those represented by ancient slope successions. Moreover, present-day highstand conditions may not provide a good analogue for lowstand slope settings. Future research efforts will also concentrate on better calibration of seismic facies to rock facies and linking of physical and numerical (process and forward) modelling techniques at different scales to observational datasets. The future lies in integration of these complementary research directions.Our understanding of the erosion, bypass, deposition and remobilization processes that operate on submarine slopes and the stratigraphic record of these 'processes and products' has increased enormously over the last decade. The main driving forces have been the continued development and deployment of stateof-the-art seabed sonar and other imaging systems in Quaternary slope and basin floor settings (e.g. Klaucke

show abstract

The Architecture of Turbidite Slope Channels

Cited by 107 publications

References 0 publications

Genesis and character of thin-bedded turbidites associated with submarine channels

Genesis and character of thin-bedded turbidites associated with submarine channels

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

Submarine slope systems: processes and products

Contact Info

Product

Resources

About