| Titre | Channel-levee evolution in combined contour current-turbidity current flows from flume-tank experiments |
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| Auteur | Miramontes, E; Eggenhuisen, J T; Silva Jacinto, R; Poneti, G; Pohl, F; Normandeau, A ; Campbell, D C; Hernández-Molina, F J |
| Source | Geology vol. 48, 2020 p. 1-5, https://doi.org/10.1130/G47111.1  Accès ouvert |
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| Année | 2020 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190550 |
| Éditeur | Geological Society of America |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1130/G47111.1 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Sujets | évolution géologique; chenaux; courants; courants de turbidite; océanographie; milieux sédimentaires; milieux marins; marges continentales; paléocourants; configurations lit; modèles sédimentaires;
géologie marine; sédimentologie; géophysique; Nature et environnement; Sciences et technologie |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; profils géophysiques; photographies; profils; coupes transversales |
| Programme | Géosciences marines pour la planification spatiale marine |
| Diffusé | 2020 01 31 |
| Résumé | (disponible en anglais seulement)
Turbidity currents and contour currents are common sedimentary and oceanographic processes in deep-marine settings that affect continental margins worldwide.
Their simultaneous interaction can form asymmetric and unidirectionally migrating channels, which can lead to opposite interpretations of paleocontour current direction: channels migrating against the contour current or in the direction of the
contour current. In this study, we performed three-dimensional flume-tank experiments of the synchronous interaction between contour currents and turbidity currents to understand the effect of these combined currents on channel architecture and
evolution. Our results show that contour currents with a velocity of 10-19 cm/s can substantially deflect the direction of turbidity currents with a maximum velocity of 76-96 cm/s, and modify the channel-levee system architecture. A lateral and
nearly stationary front formed on the levee located upstream of the contour current, reduced overspill and thus restrained the development of a levee on this side of the channel. Sediment was preferentially carried out of the channel at the flank
located downstream of the contour current. An increase in contour-current velocity resulted in an increase in channel-levee asymmetry, with the development of a wider levee and more abundant bedforms downstream of the contour current. This asymmetric
deposition along the channel suggests that the direction of long-term migration of the channel form should go against the direction of the contour current due to levee growth downstream of the contour current, in agreement with one of the previously
proposed conceptual models. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Les courants de turbidité et les courants de contour sont communs sur les marges continentales. Ici, nous démontrons que les courants de contour
peuvent considérablement affecter la direction des courants de turbidité ainsi que l'architecture des systèmes de chenaux sous-marins. |
| GEOSCAN ID | 321866 |
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