New high-resolution acoustic data from the `braided system' of the Orinoco deep-sea fan

Ercilla, Gemma; Alonso, Belén; Baraza, J.; Casas, David; Chiocci, Francesco Latino; Estrada, Ferrán; Farran, Marcel-lí; Gonthier, E.; Pérez-Belzuz, Fernando; Pirmez, Carlos; Reeder, Michael S.; Torres, Joan Ramón; Úrgeles, Roger

doi:10.1016/s0025-3227(97)00134-5

Cited by 29 publications

(17 citation statements)

References 10 publications

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“…The diffuse return obtained from TOPAS records along the channel floor implies a relatively sandy substrate and deposition by sandy turbidity currents, and this is also supported by the bstreakedQ appearance of the surface of the lobe with its elongate zones of low and medium backscatter (cf. Ercilla et al, 1998;Klaucke et al, 2004). In contrast, the finer acoustic stratification in the channel levees points to Fig.…”

Section: Discussionmentioning

confidence: 90%

“…5A) is interpreted to reflect the role of the Coriolis force on turbidity currents travelling through the channel, which results in deflection to the right (in the Northern Hemisphere) and increased sand overspill (Clark and Pickering, 1996). Braiding has been reported from some high-and low-latitude submarine channel systems, generally from the channel-mouth lobes (e.g., Beldersen et al, 1984;Kenyon and Millington, 1995;Ercilla et al, 1998;Klaucke et al, 2004;Ó Cofaigh et al, 2004). Both Ercilla et al (1998) and Hesse et al (2001) have suggested that the development of braiding relates to changes in flow power, which, in turn, are associated with increases in sediment and/or flow discharge.…”

Section: Discussionmentioning

confidence: 99%

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Geophysical investigations of a high-latitude submarine channel system and associated channel-mouth lobe in the Lofoten Basin, Polar North Atlantic

2006

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Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Geophysical investigations of a high-latitude submarine channel system and associated channel-mouth lobe in the Lofoten Basin, Polar North Atlantic

2006

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“…Like fluvial channels, meandering is perhaps the most commonly observed planform among submarine channels. Although not common, straight (Klaucke et al, 1998) and braided (Ercilla et al, 1998) channel patterns have also been observed in the submarine environment. The length of submarine channels varies from a few kilometres to several thousand kilometres.…”

Section: Channelization and Channel Processesmentioning

confidence: 99%

The Mechanics of Marine Sediment Gravity Flows

Parsons

Friedrichs

Traykovski

et al. 2007

Continental Margin Sedimentation

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Sediment gravity flows, particularly those in the marine environment, are dynamically interesting because of the non-linear interaction of mixing, sediment entrainment/suspension and water-column stratification. Turbidity currents, which are strongly controlled by mixing at their fronts, are the best understood mode of sediment gravity flows. The type of mixing not only controls flow and deposition near the front, but also changes the dynamics of turbidity currents flowing in self-formed channels. Debris flows, on the other hand, mix little with ambient fluid. In fact, they have been shown to hydroplane, i.e. glide on a thin film of water. Hydroplaning enables marine debris flows to runout much farther than their subaerial equivalents. Some sediment gravity flows require external energy, from sources such as surface waves. When these flows are considered as stratification-limited turbidity currents, models are able to predict observed downslope sediment fluxes. Most marine sediment gravity flows are supercritical and thus controlled by sediment supply to the water column. Therefore, the genesis of the flows is the key to their understanding and prediction. Virtually every subaqueous failure produces a turbidity current, but they engage only a small percentage of the initially failed material. Wave-induced resuspension can produce and sustain sediment gravity flows. Flooding rivers can also do this, but the complex interactions of settling and turbulence need to be better understood and measured to quantify this effect and document its occurrence. Ultimately, only integrative numerical models can connect these related phenomena, and supply realistic predictions of the marine record.

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“…These suggest that the LSC submarine channels were similar in geomorphology to terrestrial, gravelly braided rivers. The morphologic similarity between submarine channels and terrestrial rivers has been increasingly documented from recent deep-sea studies (e.g., Klaucke and Hesse 1996;Ercilla et al 1998;Abreu et al 2003;Posamentier 2003). Most of the studies are, however, concerned with mud-and sand-rich, sinuous deep-sea channels.…”

Section: Depositional Model Of the Lsc Submarine Channel Systemmentioning

confidence: 99%

Sedimentary Facies and Architecture of a Gigantic Gravelly Submarine Channel System in a Cretaceous Foredeep Trough (the Magallanes Basin, Southern Chile)

Cheo¹,

Kim²,

Jo³

et al. 2017

Ocean and Polar Research

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: The Lago Sofia conglomerate in southern Chile is a deep-marine gravelly deposit, which is hundreds of meters thick and kilometers wide and extends laterally for more than 100 km, filling the foredeep trough of the Cretaceous Magallanes Basin. For understanding the depositional processes and environments of this gigantic deep-sea conglomerate, detailed analyses on sedimentary facies, architecture and paleoflow patterns were carried out, highlighting the differences between the northern (Lago Pehoe and Lago Goic areas) and southern (Lago Sofia area) parts of the study area. The conglomerate bodies in the northern part occur as relatively thin (< 100 m thick), multiple units intervened by thick mudstone-dominated sequences. They show paleoflows toward ENE and S to SW, displaying a converging drainage pattern. In the southern part, the conglomerate bodies are vertically interconnected and form a thick (> 400 m thick) conglomerate sequence with rare intervening fine-grained deposits. Paleoflows are toward SW. The north-to-south variations are also distinct in sedimentary facies. The conglomerate bodies in the southern part are mainly composed of clast-supported conglomerate with sandy matrix, which is interpreted to be deposited from highly concentrated bedload layers under turbidity currents. Those in the northern part are dominated by matrix-to clast-supported conglomerate with muddy matrix, which is interpreted as the products of composite mass flows comprising a turbidity current, a gravelly hyperconcentrated flow and a mud-rich debris flow. All these characteristics suggest that the Lago Sofia conglomerate was formed in centripetally converging submarine channels, not in centrifugally diverging channels of submarine fans. The tributaries in the north were dominated by mass flows, probably affected by channel-bank failures or basin-marginal slope instability processes. In contrast, the trunk channel in the south was mostly filled by tractive processes, which resulted in the vertical and lateral accretion of gravel bars, deposition of gravel dunes and filling of scours and channels, similar to deposits of terrestrial gravel-bed rivers. The trunk channel developed along the axis of foredeep trough and its confinement within the trough is probably responsible for the thick, interconnected channel fills. The large-scale architecture of the trunk-channel fills shows an eastward offset stacking pattern, suggesting that the channel migrated eastwards most likely due to the uplift of the Andean Cordillera.

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New high-resolution acoustic data from the `braided system' of the Orinoco deep-sea fan

Cited by 29 publications

References 10 publications

Geophysical investigations of a high-latitude submarine channel system and associated channel-mouth lobe in the Lofoten Basin, Polar North Atlantic

Geophysical investigations of a high-latitude submarine channel system and associated channel-mouth lobe in the Lofoten Basin, Polar North Atlantic

The Mechanics of Marine Sediment Gravity Flows

Sedimentary Facies and Architecture of a Gigantic Gravelly Submarine Channel System in a Cretaceous Foredeep Trough (the Magallanes Basin, Southern Chile)

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