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TitreLate Quaternary history of contourite drifts and variations in Labrador Current flow, Flemish Pass, offshore eastern Canada
AuteurMarshall, N R; Piper, D J W; Saint-Ange, F; Campbell, D C
SourceGeo-Marine Letters vol. 34, no. 5, 2014 p. 457-470, https://doi.org/10.1007/s00367-014-0377-z
LiensSupplement
Année2014
Séries alt.Secteur des sciences de la Terre, Contribution externe 20130352
ÉditeurSpringer
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1007/s00367-014-0377-z
Mediapapier; en ligne; numérique
Formatspdf; html
ProvinceRégion extracotière de l'est
Lat/Long OENS -48.0000 -46.0000 49.0000 46.0000
Sujetsdébit de sedimentation; sedimentation; interpretations sismiques; bathymétrie; corrélations stratigraphiques; analyses stratigraphiques; carottes; courants de fond; courants; circulation du courant; Néogène; sédimentologie; géophysique; géologie marine; Quaternaire
ProgrammeGéoscience en mer
ProgrammeRisques géo marines, Géoscience pour la sécurité publique
Résumé(disponible en anglais seulement)
Contourite drifts of alternating sand and mud, shaped by the Labrador Current, formed during the late Quaternary in Flemish Pass seaward of the Grand Banks of Newfoundland, Canada. The drifts preserve a record of Labrador Current flow variations through the last glacial maximum. A high-resolution seismic profile and a transect of four cores were collected across Beothuk drift on the southeast side of Flemish Pass. Downcore and lateral trends in grain size and sedimentation rate provide evidence that, between 16 and 13 ka, sediment was partitioned across Beothuk drift and the adjacent Flemish Pass floor by a strong current flow but, from 29 to 16 ka, sedimentation was more of a blanketing style, represented by draped reflections interpreted as being due to a weaker current. The data poorly resolve the low sedimentation rates since 13 ka, but the modern Labrador Current in Flemish Pass is the strongest it has been in at least the past 29 ka. Pre-29 ka current flow is interpreted based on reflection architecture in seismic profiles. A prominent drift on the southwestern side of Flemish Pass formed above a mid-Miocene erosion surface, but was buried by a mass-transport deposit after the penultimate glacial maximum and after drift deposition switched to eastern Flemish Pass. These findings illustrate the temporal complexity of drift sedimentation and provide the first detailed proxy for Labrador Current flow since the last glacial maximum.
Résumé(Résumé en langage clair et simple, non publié)
On reconnaît pour la première fois que les accumulations de sédiments façonnées par le courant du Labrador occupent une place importante dans la géologie peu profonde de la passe Flamande, soit une zone d'exploration et d'exploitation pétrolières actives. La croissance générale des accumulations de sédiments dans le sud de la passe Flamande depuis 5 millions d'années est documentée. La croissance détaillée de ces accumulations au cours des 25 000 dernières années est également documentée.
GEOSCAN ID293390