| Titre | New evidence for a major late Quaternary submarine landslide on the external western levee of Laurentian Fan |
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| Auteur | Normandeau, A ;
Campbell, D C; Piper, D J W; Jenner, K A |
| Source | Subaqueous Mass Movements; par Lintern, D G (éd.); Mosher, D C (éd.);
Moscardelli, L G (éd.); Borrowsky, P T (éd.); Campbell, C
(éd.); Chaytor, J D (éd.); Clague, J J (éd.); Georgiopoulou, A (éd.); Lajeunesse, P (éd.); Normandeau, A (éd.); Piper, D J W (éd.); Scherwath, M (éd.); Stacey, C (éd.); Turmel, D (éd.); Geological Society, Special Publication no. 477, 2018, 11p., https://doi.org/10.1144/SP477.14  Accès ouvert |
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| Année | 2018 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20170184 |
| Éditeur | Geological Society of London |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1144/SP477.14 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Région extracotière de l'est |
| Région | Laurentian Fan; eastern Canadian continental margin |
| Lat/Long OENS | -59.0000 -54.0000 44.5000 41.0000 |
| Sujets | dépôts de glissement de terrain; glissements de terrain; caractéristiques sous-marines; fosses abyssales; bathymétrie; dorsales sous-marines; dépôts de coulée de débris; cônes de déjection; levés de
reflexion sismiques; levés sismiques marins; géologie marine; géologie des dépôts meubles/géomorphologie |
| Illustrations | cartes de localisation; profils sismiques |
| Programme | Délimitation du plateau continental du Canada en vertu de la Convention des Nations Unies sur le droit de la mer (UNCLOS) |
| Diffusé | 2018 03 28 |
| Résumé | (disponible en anglais seulement)
The Laurentian Fan is one of the largest submarine fans on the western margin of the North Atlantic. Recently acquired high-resolution multibeam bathymetric
data (60 m horizontal resolution) reveal a major mass-transport deposit (MTD) on the Western Levee of Western Valley (WLWV), covering >14 000 km2 in water depths from 3900 to >5000 m. Typical submarine landslide features are observed such as
headscarps that in places reach the crest of the levee, crown cracks, extensional ridges, blocky debris and flow lineations. Multiple headwalls are observed on 3.5 kHz sub-bottom profiles, indicating that the landslide retrogressed upslope. While the
upper parts of the MTD consist of intact blocks that were displaced downslope as ridges and troughs, the lower parts exhibit a c. 30 m thick incoherent to transparent acoustic facies, typical of debris flows. Landslide geomorphology therefore
suggests that it was generated as a retrogressive spread and that slide blocks disintegrated downslope to become a blocky landslide with a surficial debris flow. The blocky landslide/
debris flow extends downslope c. 90 km and partially fills a
submarine channel. The superposition of the MTD filling the channel and its location at the top of the stratigraphic succession in the levee suggests that it is late Quaternary in age, possibly Holocene. Deeper seismic reflection data also show that
this is a rare event during the Quaternary; it is the largest MTD observed in the upper c. 375 m of the levee succession and among the largest and deepest in the western North Atlantic. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Nous documentons l'un des plus grands glissements de terrain sous-marins au Canada qui a récemment été cartographié sur le Fan de la
Laurentienne. L'importance de ce glissement de terrain était auparavant inconnue et a été tout récemment découverte. |
| GEOSCAN ID | 305900 |
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