GEOSCAN, résultats de la recherche

Menu GEOSCAN


TitreSubmarine mass-transport facies: new perspectives on flow processes from cores on the eastern North American margin
AuteurTripsanas, E K; Piper, D J W; Jenner, K A; Bryant, W R
SourceSedimentology vol. 55, 2008 p. 97-136, https://doi.org/10.1111/j.1365-3091.2007.00894.x
Année2008
Séries alt.Secteur des sciences de la Terre, Contribution externe 2005607
ÉditeurWiley-Blackwell
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1111/j.1365-3091.2007.00894.x
Mediapapier; en ligne; numérique
Formatshtml; pdf
ProvinceRégion extracotière de l'est
Lat/Long OENS-95.0000 -88.0000 30.0000 26.0000
Lat/Long OENS-50.0000 -47.0000 50.0000 48.0000
Sujetscaractéristiques sous-marines; transport des sediments; transport sous-marin; faciès; faciès sédimentaires; milieu sédimentaire; coulées de débris; sables; graviers; roches clastiques; dépôts de pentes; stabilité des pentes; glissements de terrain; dépôts de glissement de terrain; glissements; turbidite; courants de turbidite; levés géophysiques; interpretations sismiques; levés sismiques; levés de reflexion sismiques; profils sismiques; profils sismiques marins; viscosité; géologie marine; géologie des dépôts meubles/géomorphologie; géophysique; Quaternaire; Cénozoïque
Illustrationslocation maps; cross-sections; seismic profiles; stratigraphic columns; tables
ProgrammeLes géosciences à l'appui de la gestion des océans
ProgrammeCRSNG Conseil de recherches en sciences naturelles et en génie du Canada
ProgrammeCOSTA-CANADA - Stabilité du talus continental
ProgrammeLe Programme de recherche et de développement énergétiques (PRDE)
Diffusé2007 09 14
Résumé(disponible en anglais seulement)
No comprehensive scheme yet exists to describe the depositional products of submarine sediment failures at the scale of piston cores, resulting in misinterpretation of failure deposits and overuse of the genetic term 'debris flow'. Ninety-nine sediment cores (0Æ5 to 20 m in length), from offshore eastern Canada and the Gulf of Mexico, are used to propose a descriptive sedimentary facies scheme with genetic implications for mass-transport deposits. Seven facies are distinguished: (i) allochthonous stratified sediment; (ii) distorted stratified sediment; (iii) clast-supported hard-mud-clast conglomerate; (iv) matrix-supported mud-clast conglomerate; (v) thin mud-clast conglomerate (<0.8 m thick); (vi) diamicton; and (vii) sorted sand-gravel deposits (greater or equal 0.05 m thick). Seven genetic types of deposits are recognized. (i) Slumping of coherent sediment blocks (facies I). (ii) Slump and slide deposits (facies I and II). (iii) Debris-avalanche deposits (hard sediment of facies I and II overlain by facies III). (iv) Low-viscosity or large-scale, high-viscosity, cohesive debris flow deposits (facies IV, may have I, II, and III). (v) Very low-viscosity debris flow deposits (facies V). (vi) Cohesionless debris flow deposits (facies VI). (vii) High-density turbidity currents (facies VII). Vertical transitions between the genetic types were analysed by Markov chain analysis. Although sedimentological transitions are inferred between deposits of slides and cohesive debris flows, their spatial distribution indicates that a cohesive debris flow forms principally in the initial stages of a sediment failure, suggesting that transformation depends mostly on the strength of the sediments. A genetic link is suggested for cohesionless debris flow deposits, which originate from the disintegration of sandy sediment on the upper continental slope, and the closely related turbidity current deposits. Debris avalanches are common in sedimentary marine environments with steep slopes (>10°). In many cases, geometrical and seismic characteristics of debris avalanche, slide and debris flow are similar, requiring core data to verify transport process.
GEOSCAN ID221626