Deep water sediment deposition from hybrid contour-turbidity currents

Join the 'online hub for sedimentologists' for FREE at http://sedsonline.com ! If you have any questions from the presentation, please go to the Seds Online Forum (using the link above) and find the dedicated thread! *** Dr. Joris T. Eggenhuisen (speaker), E. Miramontes, R. Silva Jacinto, J. Hernández-Molina, F. Pohl, G. Poneti, and collaborators Utrecht University Two types of currents dominate sediment transport and deposition on continental slopes: sediment gravity flows that travel down the slope through submarine canyons, channels, and gullies; and bottom currents that are part of the ocean circulation and commonly flow along the slope. Continental slope morphologies reported from mixed sediment gravity flow - bottom current systems across the planet reflect various degrees of interaction between sediment gravity flows and bottom currents. Unfortunately, two communities of researchers have historically specialized in either gravity driven sediment transport or bottom current sediment transport. Consequently, the processes governing sediment transport and deposition in mixed systems are not clearly established and interpretations of mixed-system deposits in literature remain hypothetical and sometimes appear contradictory. In this seminar we will present the first measurements of combined contour-current and turbidity-current flows, which were obtained in laboratory experiments. The measurements demonstrate that contour currents flowing at 10 % of the turbidity current speed can pervasively deflect the turbidity current flow and prove for the first time that hybrid bottom-turbidity currents can be at the origin of asymmetric channel-levee systems. These first experiments are the starting point for discussions on the themes that need to be addressed by the deep water community to achieve an integrated understanding of sediment deposition in deep water environments by contour currents and turbidity currents.