Description of a contourite depositional system on the Demerara Plateau: Results from geophysical data and sediment cores

Tallobre, Cédric; Loncke, Lies; Bassetti, Maria‐Angela; Giresse, Pierre; Bayon, Germain; Buscail, Roselyne; Madron, Xavier Durrieu de; Bourrin, François; Vanhaesebroucke, Marc; Sotin, C.

doi:10.1016/j.margeo.2016.01.003

Cited by 31 publications

(50 citation statements)

References 78 publications

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“…The structure and history of the Demerara Plateau is quite well known due to the availability of industry and ODP drill cores (Gouyet, 1988;ODP leg 159, Mosher et al, 2007), long offset deep-penetrating reflection and refraction seismic data (Greenroyd et al, 2007(Greenroyd et al, , 2008Mercier de Lépinay, 2016, Reuber et al, 2016Klingelhoefer et al, 2017), as well as academic exploration and sampling cruises (Loncke et al, 2009, 20162015;Tallobre et al, 2016). The basins hosted by this plateau have been particularly well described in comparison with those of other TMPs.…”

Section: Demeraramentioning

confidence: 99%

“…along the continental shelf and upper marginal plateau ( Figure 6) and decreases towards the ocean. The outer marginal plateau, at a distance of nearly 200 km from the shoreline, is considered to be nearly sediment starved at present (Mosher et al, 2007), except along a contourite drift that parallels the edges of the plateau (Tallobre et al, 2016;Fanget et al, submitted). The contourite drift is shown in Figure 6C (labelled CDS for Contourite Depositional System).…”

Section: Demeraramentioning

confidence: 99%

“…along the continental margins". This is especially the case along outstanding TMPs where they are accelerated and build important contourite depositional systems (Tallobre et al, 2016).…”

Section: Tmp Sedimentary Archivesmentioning

confidence: 99%

“…(2) During a second transitional middle Miocene to early Pliocene stage, regional erosion and slope destabilization marked major changes in oceanic circulation that led to the permanent establishment of modern thermohaline circulation (Niemi et al, 2000;Pfuhl and McCave, 2005;Hernandez-Molina et al, 2009;Herold et al, 2012;Uenzelmann-Neben et al, 2016). At this time, a first contourite terrace shapes the plateau, (3) Finally, during a Plio-Quaternary contourite stage the plateau is dominantly shaped by bottom-currents, respectively the north-flowing AAIW (Antarctic Intermediate Water) in the upper plateau, the south-flowing North Atlantic Deep Water (NADW) on the outer plateau and the deeper north-flowing Antarctic Bottom Water at the foot of the plateau on the Demerara abyssal plain (Tallobre et al, 2016;Fanget et al, 2017).…”

Section: Tmps: Their Role On Oceanic Circulationmentioning

confidence: 99%

“…This observation is not conclusive, since Rebesco et al (2014) underline that those bottom-current controlled features are ubiquitous in marine basins. Loncke et al (2016) and Tallobre et al (2016) propose that the presence of transform marginal plateaus that extend the continental shelf seaward and reach important depths could affect deep current dynamics in constraining and accelerating deep current flows. TMPs may therefore be considered as key domains able to record slight variations in current intensity especially in transitional periods of climatic-related current intensification or reduction.…”

Section: Tmps: Their Role On Oceanic Circulationmentioning

confidence: 99%

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Transform Marginal Plateaus

Loncke

Roest

Klingelhoëfer

et al. 2020

Earth-Science Reviews

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Numerous submarine plateaus form highstanding bathymetric highs at continent to ocean transitions. Due to their proximity to continents, they have been frequently labelled "marginal plateaus", although this term has not been clearly defined or associated with a specific geology or geodynamic process. Until now, these elevations have been interpreted as submerged thinned continental fragments detached from continents, basaltic buildups formed by hotspots, volcanic margins or oceanic plateaus. Many of these plateaus formed at transform margins connecting oceanic basins of contrasted ages. We propose for the first time to define and review a class of marginal plateaus related to a specific tectonic setting: "Transform Marginal Plateaus" (TMPs). Based on a compilation of 20 TMPs around the world, we show that most of them have a polyphased history and have undergone at least one major volcanic phase. Our review highlights in particular a hitherto unrecognized close link between hotspots, volcanic activity and transform margins. We also propose that, due to their polyphased history, TMPs may contain several successive basins and overlooked long-lived sedimentary archives. We finally highlight that, because these TMPs were transform plate boundaries perpendicular or oblique to surrounding rifts, many of them were close to lastcontact points during final continental breakup and may have formed land bridges or bathymetric highs between continents. Therefore, we discuss broader scientific issues, such as the interest of TMPs in recording and studying the onset and variations of oceanic currents or past biodiversity growth, bioconnectivity and lineage evolution.

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Section: Demeraramentioning

confidence: 99%

Section: Demeraramentioning

confidence: 99%

“…along the continental margins". This is especially the case along outstanding TMPs where they are accelerated and build important contourite depositional systems (Tallobre et al, 2016).…”

Section: Tmp Sedimentary Archivesmentioning

confidence: 99%

Section: Tmps: Their Role On Oceanic Circulationmentioning

confidence: 99%

Section: Tmps: Their Role On Oceanic Circulationmentioning

confidence: 99%

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Transform Marginal Plateaus

Loncke

Roest

Klingelhoëfer

et al. 2020

Earth-Science Reviews

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Palaeoceanographic and hydrodynamic variability for the last 47 kyr in the southern Gulf of Cádiz (Atlantic Moroccan margin): Sedimentary and climatic implications

Vandorpe

Delivet

Blamart

et al. 2022

The Depositional Record

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X-ray fluorescence, grain-size and oxygen and carbon stable isotope measurements of a 33 m long piston core, recovered from the Pen Duick drift located at the foot of the prominent Pen Duick Escarpment (Atlantic Moroccan margin), are combined to decipher past oceanographic conditions. The data indicate that, similar to the northern Gulf of Cádiz, the Azores Front exerts a major control on the palaeoclimatology of the region. Contrasting to the northern Gulf of Cádiz, where Mediterranean Outflow Water is the main water mass at similar water depths, the palaeoceanography of the studied area is mostly influenced by the amount of Antarctic Intermediate Water advected from the south. The density contrast between the Antarctic Intermediate Water and the overlying North Atlantic Central Water determined the strength of the prevailing internal tides and corresponding high current speeds, which drastically impacted the sedimentary record. The most notable impact is the presence of a 7.8 kyr condensed section (30.5-22.7 ka BP). The formation of the Pen Duick sediment drift was not just controlled by the strength of the bottom currents and the intensity of the internal tides, but also by the amount of (aeolian) sediment supplied to the region. Although variable, drift-growth phases seem to mainly occur during colder periods of the last glacial, i.e. Heinrich and Dansgaard-Oeschger events during the Marine Isotope Stage 3 and the late Marine Isotope Stage 2. These periods, characterised by increased aeolian dust supply and higher bottom currents, coincide with a phase of prolific cold-water coral growth and enhanced coral mound formation as recorded in numerous cores obtained from the southern Gulf of Cádiz. This implies that both records (on and off mound cores) are pivotal to provide the complete picture of the palaeo-climatic and palaeooceanographic conditions in the region.

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Pockmarks on the South Aquitaine Margin continental slope: The seabed expression of past fluid circulation and former bottom currents

Michel

Dupré

Baltzer

et al. 2017

Comptes Rendus. Géoscience

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Inactive and mostly elongated pockmarks of 100-200 m in dimension were recently discovered on the South Aquitaine Margin continental slope. They are distributed at water depths greater than 350 m in both interfluve and sediment-wave areas, and are strongly controlled by the sedimentary morphology and architecture. Water column and seafloor backscatter and sub-bottom profiler data do not exhibit present-day or past gas evidence, e.g., massive and continuous gas releases at the seabed and fossil methane-derived authigenic carbonates. It is thus proposed that the pockmarks originated from a shallow source and result from relatively recent and short-duration gas or water expulsion events. Former near-bottom currents may have contributed to the elongation of these WNW-ESEoriented pockmarks, whereas present-day weaker near-bottom currents may induce upwelling, contributing to the maintenance of the elongated shapes of the pockmarks.

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Description of a contourite depositional system on the Demerara Plateau: Results from geophysical data and sediment cores

Abstract: Highlights ► A Contourite Depositional System (CDS) is present on the Demerara Plateau. ► The marginal plateau forms a bathymetry high promoting the formation of contourite. ► The formation of longitudinal waves seems to be associated to this contourite.

Cited by 31 publications

References 78 publications

Transform Marginal Plateaus

Transform Marginal Plateaus

Palaeoceanographic and hydrodynamic variability for the last 47 kyr in the southern Gulf of Cádiz (Atlantic Moroccan margin): Sedimentary and climatic implications

Pockmarks on the South Aquitaine Margin continental slope: The seabed expression of past fluid circulation and former bottom currents

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