High-resolution seismo-acoustic studies of alongslope and downslope sediment transport processes shaping depositional patterns at continental margins

Abstract

Downslope and alongslope sediment transports represent important processes during the evolution of continental margins. This thesis reveals the impact of both transport processes on slope architecture in highly dynamic oceanographic settings and assesses their interaction using seismo- and hydroacoustic data. The study area covers the northern Argentine continental slope, where a contourite depositional system is located beneath the Brazil-Malvinas Confluence. The most prominent sedimentary features are represented by contourite terraces and the Mar del Plata canyon (MdP). Analysis of the slope architecture revealed the major influence of North Atlantic Deep Water production on the margin evolution since the Middle Miocene. The variability of morphosedimentary features with respect to the oceanographic regime indicates that contourite terraces are linked to water mass interfaces. The lack of sediments north of the MdP is the result of the disturbance of the current regime caused by the canyon. The importance of alongslope transport processes is shown in a novel study off Mozambique using hydroacoustic data imaging particles in water depth >200 m.