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TitreNew evidence for widespread mass transport on the Northeast Newfoundland Shelf revealed by Olex single-beam echo sounding
AuteurShaw, J; Piper, D J W; Skulski, T; Lamplugh, M J; Craft, A; Roy, A
SourceGeo-Marine Letters vol. 32, no. 1, 2012 p. 5-15,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100466
ÉditeurSpringer Nature
Documentpublication en série
Mediapapier; en ligne; numérique
Formatspdf; html
ProvinceRégion extracotière
Lat/Long OENS-56.0000 -52.0000 52.0000 50.0000
Sujetstransport sous-marin; caractéristiques sous-marines; transport des sediments; bathymétrie; topographie du fond océanique; topographie du fond océanique; levés de reflexion sismiques; géologie marine; géophysique
Illustrationsimages; profiles
ProgrammeGéoscience en mer, La géoscience pour les développements extracôtiers de la côte est
Diffusé2011 05 21
Résumé(disponible en anglais seulement)
Based on Olex single-beam sounder data, multibeam sonar surveys, and sparse seismic reflection profiles, we recognize a large area of anomalous bathymetry on the Northeast Newfoundland Shelf as having formed as a result of mass-transport processes. Transported masses include (1) an arcuate ridge of deformed material with an area of 430 km2, which has moved distances of ~20 km; (2) a 70-km2 mass of deformed material displaced 50 km along a nearly horizontal track flanked by 90-m-high berms. The movement of these and other sediment bodies has created a 150-m-high headwall escarpment extending 110 km along the north flank of the Notre Dame glacial trough. In addition, a 35-km2 block of undeformed material has moved 5 km to the southeast, away from the headwall, creating a gap of the same dimensions, while a smaller block of material originating in this vicinity has been displaced 24 km in the opposite direction, creating a 20-m-deep groove on the seafloor. There is evidence for mass transport and headwall formation elsewhere on the Northeast Newfoundland Shelf. Analysis of seismic reflection data indicates that the transported material most likely consists of stacked Quaternary till sheets that overlie Cenozoic, Mesozoic and older sedimentary rocks. Given the very low gradients involved, glaciotectonism is the most likely process to account for transport and deformation of the large sediment masses. However, some mass transport may have resulted from submarine sliding away from the headwalls that were created by the glacial transport