Contour current imprints and contourite drifts in the Bahamian archipelago

Thierry Mulder, Emmanuelle Ducassou, Vincent Hanquiez, Mélanie Principaud, Kelly Fauquembergue, Elsa Tournadour, Ludivine Chabaud, John Reijmer, Audrey Recouvreur, Hervé Gillet, Jean Borgomano, Anais Schmitt, Paul Moal

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

New data collected along the slopes of Little and Great Bahama Bank and the abyssal plain of the Bahama Escarpment provides new insights about contour current-related erosive structures and associated deposits. The Bahamian slope shows abundant evidence of bottom current activity such as furrows, comet-like structures, sediment waves and drifts. At a seismic scale, large erosion surfaces and main periods of drift growth resulted from current acceleration related to plate tectonic processes and progressive opening and closure of gateways and long-term palaeoclimate evolution. At present-day, erosion features and contourite drifts are either related to relatively shallow currents (<1000 m water depth) or to deep currents (>2500 m water depth). It appears that the carbonate nature of the drifts does not impact the drift morphology at the resolution addressed in the present study. Classical drift morphologies defined in siliciclastic environments are found, such as mounded, plastered and separated drifts. In core, contourite sequences show a bi-gradational trend that resembles classical contourite sequences in siliciclastic deposits showing a direct relationship with a change in current velocity at the sea floor. However, in a carbonate system the peak in grain size is associated with increased winnowing rather than increased sediment supply as in siliciclastic environments. In addition, the carbonate contourite sequence is usually thinner than in siliciclastics because of lower sediment supply rates. Little Bahama Bank and Great Bahama Bank contourites contain open-ocean input and slope-derived debris from glacial episodes. Inner platform, platform edge and open ocean pelagic input characterize the classical periplatform ooze during interglacials. In all studied examples, the drift composition depends on the sea floor topography surrounding the drift location and the type of sediment supply. Carbonate particles are derived from either the slope or the platform in slope and toe of slope drifts, very deep contourites have distant siliciclastic sources of sediment supply. The recent discovery of the importance of a large downslope gravitary system along Bahamian slopes suggests frequent interactions between downslope and along-slope (contour currents) processes. The interlayering of mass flow deposits and contourites at a seismic scale or the presence of surface structures associated with both contour currents and mass flow processes shows that both processes act at the same location. Finally, contour currents have an important impact on the repartition of deep-water coral mounds. Currents can actively interact with mounds as a nutrient and oxygen supplier or have a passive interaction, with mounds solely being obstacles orienting erosion and deposition.

Original languageEnglish
Pages (from-to)1192-1221
Number of pages30
JournalSedimentology
Volume66
Issue number4
Early online date3 Feb 2019
DOIs
Publication statusPublished - Jun 2019

Fingerprint

contourite
archipelago
open ocean
carbonate
sediment
seafloor
erosion feature
siliciclastic deposit
sediment wave
erosion
ooze
carbonate system
abyssal plain
bottom current
escarpment
plate tectonics
paleoclimate
comet
coral
water depth

Keywords

  • Bahamas
  • contour currents
  • contourites
  • drifts

Cite this

Mulder, T., Ducassou, E., Hanquiez, V., Principaud, M., Fauquembergue, K., Tournadour, E., ... Moal, P. (2019). Contour current imprints and contourite drifts in the Bahamian archipelago. Sedimentology, 66(4), 1192-1221. https://doi.org/10.1111/sed.12587
Mulder, Thierry ; Ducassou, Emmanuelle ; Hanquiez, Vincent ; Principaud, Mélanie ; Fauquembergue, Kelly ; Tournadour, Elsa ; Chabaud, Ludivine ; Reijmer, John ; Recouvreur, Audrey ; Gillet, Hervé ; Borgomano, Jean ; Schmitt, Anais ; Moal, Paul. / Contour current imprints and contourite drifts in the Bahamian archipelago. In: Sedimentology. 2019 ; Vol. 66, No. 4. pp. 1192-1221.
@article{4fadc7c940d945b0a08d641a46790771,
title = "Contour current imprints and contourite drifts in the Bahamian archipelago",
abstract = "New data collected along the slopes of Little and Great Bahama Bank and the abyssal plain of the Bahama Escarpment provides new insights about contour current-related erosive structures and associated deposits. The Bahamian slope shows abundant evidence of bottom current activity such as furrows, comet-like structures, sediment waves and drifts. At a seismic scale, large erosion surfaces and main periods of drift growth resulted from current acceleration related to plate tectonic processes and progressive opening and closure of gateways and long-term palaeoclimate evolution. At present-day, erosion features and contourite drifts are either related to relatively shallow currents (<1000 m water depth) or to deep currents (>2500 m water depth). It appears that the carbonate nature of the drifts does not impact the drift morphology at the resolution addressed in the present study. Classical drift morphologies defined in siliciclastic environments are found, such as mounded, plastered and separated drifts. In core, contourite sequences show a bi-gradational trend that resembles classical contourite sequences in siliciclastic deposits showing a direct relationship with a change in current velocity at the sea floor. However, in a carbonate system the peak in grain size is associated with increased winnowing rather than increased sediment supply as in siliciclastic environments. In addition, the carbonate contourite sequence is usually thinner than in siliciclastics because of lower sediment supply rates. Little Bahama Bank and Great Bahama Bank contourites contain open-ocean input and slope-derived debris from glacial episodes. Inner platform, platform edge and open ocean pelagic input characterize the classical periplatform ooze during interglacials. In all studied examples, the drift composition depends on the sea floor topography surrounding the drift location and the type of sediment supply. Carbonate particles are derived from either the slope or the platform in slope and toe of slope drifts, very deep contourites have distant siliciclastic sources of sediment supply. The recent discovery of the importance of a large downslope gravitary system along Bahamian slopes suggests frequent interactions between downslope and along-slope (contour currents) processes. The interlayering of mass flow deposits and contourites at a seismic scale or the presence of surface structures associated with both contour currents and mass flow processes shows that both processes act at the same location. Finally, contour currents have an important impact on the repartition of deep-water coral mounds. Currents can actively interact with mounds as a nutrient and oxygen supplier or have a passive interaction, with mounds solely being obstacles orienting erosion and deposition.",
keywords = "Bahamas, contour currents, contourites, drifts",
author = "Thierry Mulder and Emmanuelle Ducassou and Vincent Hanquiez and M{\'e}lanie Principaud and Kelly Fauquembergue and Elsa Tournadour and Ludivine Chabaud and John Reijmer and Audrey Recouvreur and Herv{\'e} Gillet and Jean Borgomano and Anais Schmitt and Paul Moal",
year = "2019",
month = "6",
doi = "10.1111/sed.12587",
language = "English",
volume = "66",
pages = "1192--1221",
journal = "Sedimentology",
issn = "0037-0746",
publisher = "Wiley-Blackwell",
number = "4",

}

Mulder, T, Ducassou, E, Hanquiez, V, Principaud, M, Fauquembergue, K, Tournadour, E, Chabaud, L, Reijmer, J, Recouvreur, A, Gillet, H, Borgomano, J, Schmitt, A & Moal, P 2019, 'Contour current imprints and contourite drifts in the Bahamian archipelago' Sedimentology, vol. 66, no. 4, pp. 1192-1221. https://doi.org/10.1111/sed.12587

Contour current imprints and contourite drifts in the Bahamian archipelago. / Mulder, Thierry; Ducassou, Emmanuelle; Hanquiez, Vincent; Principaud, Mélanie; Fauquembergue, Kelly; Tournadour, Elsa; Chabaud, Ludivine; Reijmer, John; Recouvreur, Audrey; Gillet, Hervé; Borgomano, Jean; Schmitt, Anais; Moal, Paul.

In: Sedimentology, Vol. 66, No. 4, 06.2019, p. 1192-1221.

Research output: Contribution to JournalArticleAcademicpeer-review

TY - JOUR

T1 - Contour current imprints and contourite drifts in the Bahamian archipelago

AU - Mulder, Thierry

AU - Ducassou, Emmanuelle

AU - Hanquiez, Vincent

AU - Principaud, Mélanie

AU - Fauquembergue, Kelly

AU - Tournadour, Elsa

AU - Chabaud, Ludivine

AU - Reijmer, John

AU - Recouvreur, Audrey

AU - Gillet, Hervé

AU - Borgomano, Jean

AU - Schmitt, Anais

AU - Moal, Paul

PY - 2019/6

Y1 - 2019/6

N2 - New data collected along the slopes of Little and Great Bahama Bank and the abyssal plain of the Bahama Escarpment provides new insights about contour current-related erosive structures and associated deposits. The Bahamian slope shows abundant evidence of bottom current activity such as furrows, comet-like structures, sediment waves and drifts. At a seismic scale, large erosion surfaces and main periods of drift growth resulted from current acceleration related to plate tectonic processes and progressive opening and closure of gateways and long-term palaeoclimate evolution. At present-day, erosion features and contourite drifts are either related to relatively shallow currents (<1000 m water depth) or to deep currents (>2500 m water depth). It appears that the carbonate nature of the drifts does not impact the drift morphology at the resolution addressed in the present study. Classical drift morphologies defined in siliciclastic environments are found, such as mounded, plastered and separated drifts. In core, contourite sequences show a bi-gradational trend that resembles classical contourite sequences in siliciclastic deposits showing a direct relationship with a change in current velocity at the sea floor. However, in a carbonate system the peak in grain size is associated with increased winnowing rather than increased sediment supply as in siliciclastic environments. In addition, the carbonate contourite sequence is usually thinner than in siliciclastics because of lower sediment supply rates. Little Bahama Bank and Great Bahama Bank contourites contain open-ocean input and slope-derived debris from glacial episodes. Inner platform, platform edge and open ocean pelagic input characterize the classical periplatform ooze during interglacials. In all studied examples, the drift composition depends on the sea floor topography surrounding the drift location and the type of sediment supply. Carbonate particles are derived from either the slope or the platform in slope and toe of slope drifts, very deep contourites have distant siliciclastic sources of sediment supply. The recent discovery of the importance of a large downslope gravitary system along Bahamian slopes suggests frequent interactions between downslope and along-slope (contour currents) processes. The interlayering of mass flow deposits and contourites at a seismic scale or the presence of surface structures associated with both contour currents and mass flow processes shows that both processes act at the same location. Finally, contour currents have an important impact on the repartition of deep-water coral mounds. Currents can actively interact with mounds as a nutrient and oxygen supplier or have a passive interaction, with mounds solely being obstacles orienting erosion and deposition.

AB - New data collected along the slopes of Little and Great Bahama Bank and the abyssal plain of the Bahama Escarpment provides new insights about contour current-related erosive structures and associated deposits. The Bahamian slope shows abundant evidence of bottom current activity such as furrows, comet-like structures, sediment waves and drifts. At a seismic scale, large erosion surfaces and main periods of drift growth resulted from current acceleration related to plate tectonic processes and progressive opening and closure of gateways and long-term palaeoclimate evolution. At present-day, erosion features and contourite drifts are either related to relatively shallow currents (<1000 m water depth) or to deep currents (>2500 m water depth). It appears that the carbonate nature of the drifts does not impact the drift morphology at the resolution addressed in the present study. Classical drift morphologies defined in siliciclastic environments are found, such as mounded, plastered and separated drifts. In core, contourite sequences show a bi-gradational trend that resembles classical contourite sequences in siliciclastic deposits showing a direct relationship with a change in current velocity at the sea floor. However, in a carbonate system the peak in grain size is associated with increased winnowing rather than increased sediment supply as in siliciclastic environments. In addition, the carbonate contourite sequence is usually thinner than in siliciclastics because of lower sediment supply rates. Little Bahama Bank and Great Bahama Bank contourites contain open-ocean input and slope-derived debris from glacial episodes. Inner platform, platform edge and open ocean pelagic input characterize the classical periplatform ooze during interglacials. In all studied examples, the drift composition depends on the sea floor topography surrounding the drift location and the type of sediment supply. Carbonate particles are derived from either the slope or the platform in slope and toe of slope drifts, very deep contourites have distant siliciclastic sources of sediment supply. The recent discovery of the importance of a large downslope gravitary system along Bahamian slopes suggests frequent interactions between downslope and along-slope (contour currents) processes. The interlayering of mass flow deposits and contourites at a seismic scale or the presence of surface structures associated with both contour currents and mass flow processes shows that both processes act at the same location. Finally, contour currents have an important impact on the repartition of deep-water coral mounds. Currents can actively interact with mounds as a nutrient and oxygen supplier or have a passive interaction, with mounds solely being obstacles orienting erosion and deposition.

KW - Bahamas

KW - contour currents

KW - contourites

KW - drifts

UR - http://www.scopus.com/inward/record.url?scp=85061778957&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85061778957&partnerID=8YFLogxK

U2 - 10.1111/sed.12587

DO - 10.1111/sed.12587

M3 - Article

VL - 66

SP - 1192

EP - 1221

JO - Sedimentology

JF - Sedimentology

SN - 0037-0746

IS - 4

ER -

Mulder T, Ducassou E, Hanquiez V, Principaud M, Fauquembergue K, Tournadour E et al. Contour current imprints and contourite drifts in the Bahamian archipelago. Sedimentology. 2019 Jun;66(4):1192-1221. https://doi.org/10.1111/sed.12587