| Title | Channel-levee evolution in combined contour current-turbidity current flows from flume-tank experiments |
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| Author | 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  Open Access |
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| Year | 2020 |
| Alt Series | Natural Resources Canada, Contribution Series 20190550 |
| Publisher | Geological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Subjects | marine geology; sedimentology; geophysics; Nature and Environment; Science and Technology; geological evolution; channels; currents; turbidity currents; oceanography; sedimentary environments; marine
environments; continental margins; paleocurrents; bedforms; depositional models |
| Illustrations | location maps; geoscientific sketch maps; geophysical profiles; photographs; profiles; cross-sections |
| Program | Marine Geoscience for Marine Spatial Planning |
| Released | 2020 01 31 |
| Abstract | 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. |
| Summary | (Plain Language Summary, not published)
Turbidity currents and contour currents are common processes in deep-marine settings that affect continental margins worldwide. Their interaction can
form particular sedimentary bodies. Here, we show that contour currents can substantially deflect the direction of turbidity currents, affect the entire gravitational flow and modify the channel-levee system architecture. |
| GEOSCAN ID | 321866 |
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