Titre | Near-surface geology and sediment-failure geohazards of the central Scotian Slope |
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Auteur | Mosher, D C ;
Piper, D J W ; Campbell, D C ; Jenner, K A |
Source | American Association of Petroleum Geologists Bulletin vol. 88, no. 6, 2004 p. 703-723 |
Liens | Online - En ligne
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Année | 2004 |
Séries alt. | Commission géologique du Canada, Contributions aux publications extérieures 2003054 |
Éditeur | American Association of Petroleum Geologists |
Document | publication en série |
Lang. | anglais |
Media | papier; en ligne; numérique |
Formats | pdf |
Province | Région extracotière de l'est |
SNRC | 10N |
Région | Scotian Slope; Logan Canyon; Mohican Canyon; Verrill Canyon; Dawson Canyon |
Lat/Long OENS | -62.5000 -58.6667 44.2500 42.3333 |
Sujets | talus continental; glissements de pentes; stabilité des pentes; structures de glissement; levés au sonar; profils sismiques marins; coulées de débris; boues; sables; diapirs de sel; courants de turbidite;
âges relatifs; glaciation; mécanismes d'écoulement; géologie de l'ingénieur; géologie marine; géologie des dépôts meubles/géomorphologie; Quaternaire; Cénozoïque |
Illustrations | cartes de localisation; tableaux; profils; coupes stratigraphiques; profils bathymétriques; corrélations stratigraphiques |
Programme | Le Programme de recherche et de développement énergétiques (PRDE) |
Diffusé | 2004 01 01 |
Résumé | (disponible en anglais seulement) The central Scotian Slope demonstrates a complex seafloor morphology super-imposed on a regional gradient of 2-4degrees across the margin. The west-central
Scotian Slope is characterized by a relatively smooth seafloor, but with numerous 10-80-m (33-260-ft) high escarpments representing slide failure scars. In the east, the seafloor is highly dissected by canyons. Throughout the region are scars and
deposits of sediment mass failures, including retrogressive headwalls, rotational slumps, slides, creep, debris-flow deposits, and turbidites. The complexity of failure styles and triggering mechanisms identified underscores the need for
comprehensive site assessments for situating seabed facilities. Critical factors that need to be taken into account include local terrain analysis and shallow subbottom stratigraphy. Slope-stability analysis has shown the surface sediment to be
statically stable, except on steep escarpments and canyon walls. There is evidence, however, of sediment failures that approximately correlate to glacial advances (25-12, similar to 75, and similar to 130 ka), providing some clue as to potential
triggering mechanisms. Sparse, passive-margin, tectonic earthquakes, however, are the likely cause for large-scale, regionally correlated failures and failure escarpments. |
GEOSCAN ID | 214430 |
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