The interplay between turbidity and contour current processes on the Columbia Channel fan drift, Southern Brazil Basin
Massé, L.; Faugeres, J.-C.; Hrovatin, V. (1998). The interplay between turbidity and contour current processes on the Columbia Channel fan drift, Southern Brazil Basin. Sediment. Geol. 115(1-4): 111-132. https://dx.doi.org/10.1016/s0037-0738(97)00089-4
In: Sedimentary Geology. Elsevier: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0037-0738; e-ISSN 1879-0968, meer
|  |
| Trefwoorden |
Sediments > Clastics > Contourites
Sediments > Clastics > Turbidites
|
| Author keywords |
Brazil Basin; AABW; echofacies; contour currents |
| Auteurs | | Top | Datasets |
- Massé, L.
- Faugeres, J.-C.
- Hrovatin, V.
|
|
|
| Abstract |
Channel fan drift system (Southern Brazil Basin), were investigated on the basis of 3.5-kHz echosounding profiles and core lithology. This system is composed of a sediment levee elongated downslope with a W-E then SW-NE trend, bounded to the south by the Columbia Channel and to the north by the Vitoria-Trindade seamounts. Turbidites are widespread on the shallowest part of the system: (1) thick turbidite sequences composed of quartz-rich sandy material originating from the upper continental margin are found in the axis of the channel; the turbidity currents do not significantly overflow the northern levee, where only sparse and thin silty-muddy turbidites, occur close to the axis of the channel; (2) the major part of the levee shows quartz-poor, mica- and foram-rich turbidite material originating from the Vitoria-Trindade seamounts. The abundance of this material decreases southwards and eastwards. The whole area is swept by the northward flowing Antarctic Bottom Water. Contour-current deposited muds are dominant on the southern flank of the Columbia Channel, free of any turbidite supply as a consequence of the Coriolis effect, and on the deepest part of the northern levee, remote from turbidite source areas. However, the contour currents interplay with the turbidity currents on the shallowest part of the levee. Contour-current deposited muds are interbedded with silty-sandy turbidite sequences, and a part of the muddy material has probably been pirated from the finer tails of the turbidity flows, the other part being transported from southernmost areas by the bottom currents. The interplay of both processes is also responsible for the deposition of silty turbidite beds, top-truncated by contour currents and overlain by bioturbated muddy contourites. |
| Datasets (2) |
- Flanders Marine Institute; Renard Centre of Marine Geology - Ugent (2018). Global contourite distribution database, version 2. Available online at https://www.marineregions.org, meer
- Flanders Marine Institute; Renard Centre of Marine Geology - Ugent (2019). Global contourite distribution database, version 3. Available online at https://www.marineregions.org, meer
|
|
