Sedimentary features and processes in deep-water systems: Examples from Iberian margin and Congo submarine fans
Speaker: Shih-Lin Tseng
Abstract
Deep-water sedimentary systems are highly complex. The influence includes sediment supply, climate change, water flow regime, geohazard events, and the distribution of ecosystems. This research respectively examines the sedimentary features and processes in the Nazare, Setubal submarine canyons, and Congo submarine turbitite channel. The Nazare and Setubal canyons are two largest canyons of the west Iberian continental margin. The Congo submarine channel is locates on the Congo-Angolan margin. This study to present part of the complete sidescan sonar dataset, which, in combination with multibeam bathymetry, shallow seismic profiles and precise piston core. Then, they use all of the data to characterize the sedimentary dynamics of these deep-water settings. They display a range of sedimentary features and processes that reflect changes in downslope channel geometry and a transition from erosive proximal to more depositional distal sections. Results show turbidity currents are the dominant process of sediment transport, erosion and deposition in Nazare and Setubal canyons (the proximal sections), and recognize two main types of turbidity current and their deposits that occur in the canyon . In the distal section shows the evolution of the channel path is very similar to fluvial meandering systems with (1) lateral meander extension or growing, (2) downstream translation of the thalweg, and (3) meander cutoff.
Reference
Arzola, R.G., Wynn, R.B., Lastras, G., Masson, D.G., and Weaver, P.P.E., 2008. Sedimentary features and processes in the Nazare and Setubal submarine canyons, west Iberian margin. Marine Geology, 250, 64-88.
Babonneau, N., Savoye, B., Cremer, M., and Bez, M., 2010. Sedimentary architecture in meanders of a submarine channel: detailed study of the present Congo turbidite channel (ZAIANGO project). Journal of Sedimentary Research, 80, 852-866.