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Submarine canyon morphologies and evolution in modern carbonate settings: The northern slope of Little Bahama Bank, Bahamas

dc.rights.licenseopenen_US
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorTOURNADOUR, Elsa
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorMULDER, Thierry
hal.structure.identifierCentre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
dc.contributor.authorBORGOMANO, Jean
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorGILLET, Herve
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorCHABAUD, Ludivine
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorDUCASSOU, Emmanuelle
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorHANQUIEZ, Vincent
dc.contributor.authorETIENNE, Samuel
dc.date.accessioned2024-10-07T09:25:53Z
dc.date.available2024-10-07T09:25:53Z
dc.date.issued2017-09-01
dc.identifier.issn0025-3227en_US
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/202275
dc.description.abstractEnThe recent high-quality multibeam echosounder swath bathymetry data and very high-resolution seismic profiles collected along the northern slope of Little Bahama Bank (LBB, Bahamas) constitute a unique dataset that can be used to investigate submarine canyon morphologies in modern carbonate settings. This region represents one of the few examples of submarine canyons that have developed in a purely carbonate system around the world. Our study reveals that there are 18 submarine canyons within the survey area that incise the slope between water depths of 450 m and 1000 m. Morpho-sedimentary analyses allow us to characterise their geometry and spatial distribution and to interpret their formation and control parameters. Among these canyons we distinguish four types: the amphitheatre-shaped canyons (1), canyons with up-dip linear incisions (2), canyons with internal recent depositional geometries, including levees and aggrading terraces on the side of their talweg (3) and canyons that are partially to completely filled (4). Based on these new morphological and geometrical classifications, the distributions of canyon morphologies and the integration of the full dataset, we propose a model for the formation and evolution of carbonate canyons. The latter emphasises that canyon initiation is solely the result of slope failures, which subsequently evolve into proper canyons through two successive phases of retrogressive erosion processes that are controlled by a downslope submarine cementation gradient. The first phase of retrogressive erosion produces widened canyon shapes at water depths of up to 600 m, whereas the second phase forms up dip-propagating linear incisions at water depths of up to 450 m. These linear incisions, which are located 5 to 10 km away from the platform edge, favour the funnelling of sediment fluxes originating from the platform. Subsequently or contemporaneously with this retrogressive erosion, muddy gravity flows are responsible for canyon-fills and the formation of levees and aggrading terraces, which will eventually lead to the complete infill of the canyons, marking the end of an ``erosion-fill'' cycle. On a larger scale, the persistence of such canyons on the slope of LBB is of particular interest, as these are considered to be an exception along the present-day accretionary Bahamian slopes. Although similar canyons have been identified along the western slope of Great Bahama Bank (GBB), today these are totally buried, unlike those of LBB. We therefore suggest that the persistence of LBB canyons may be the result of relatively low sedimentation rates linked with the windward orientation of the platform. This low sedimentation rate has prevented the burial of these canyons since the Pliocene.
dc.language.isoENen_US
dc.title.enSubmarine canyon morphologies and evolution in modern carbonate settings: The northern slope of Little Bahama Bank, Bahamas
dc.typeArticle de revueen_US
dc.identifier.doi10.1016/j.margeo.2017.07.014en_US
dc.subject.halPlanète et Univers [physics]/Sciences de la Terreen_US
bordeaux.journalMarine Geologyen_US
bordeaux.page76-97en_US
bordeaux.volume391en_US
bordeaux.hal.laboratoriesEPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805en_US
bordeaux.institutionUniversité de Bordeauxen_US
bordeaux.institutionCNRSen_US
bordeaux.teamGEOLSEDen_US
bordeaux.peerReviewedouien_US
bordeaux.inpressnonen_US
bordeaux.import.sourcehal
hal.identifierhal-01765624
hal.version1
hal.popularnonen_US
hal.audienceInternationaleen_US
hal.exportfalse
workflow.import.sourcehal
dc.rights.ccPas de Licence CCen_US
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Marine%20Geology&rft.date=2017-09-01&rft.volume=391&rft.spage=76-97&rft.epage=76-97&rft.eissn=0025-3227&rft.issn=0025-3227&rft.au=TOURNADOUR,%20Elsa&MULDER,%20Thierry&BORGOMANO,%20Jean&GILLET,%20Herve&CHABAUD,%20Ludivine&rft.genre=article


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