Les processus sédimentaires, depuis la pente continentale jusqu'au bassin, en contexte de tectonique active : analyse comparée entre la Marge Calabro-Ionienne et la Marge Ligure durant les derniers 5 Ma

摘要

Sediment transfer from the continental shelf to the deep basin is of great interest as it partially controls the morphological and architectural evolution of continental margins. Transfer of particles on the continental slope associates with processes of erosion and deposition that control the construction of typical features such as submarine canyons. Because they strongly erode the continental slope, canyons contribute significantly to its morphological evolution through time. However, a number of studies have evidenced submarine canyons that do not connect with sub‐aerial channelized systems, questioning their processes of formation and evolution. This study aims to better understand the processes of formation and evolution of six submarine canyons identified on the western margin of the Ligurian Basin and ten canyons systems on the Calabro-Ionian margin. From morphometric and structural analyses based respectively on bathymetric, seismic‐reflexion (24‐channel profiles) data, Chirp and SAR profiles we constrained the main morphometric characteristics (length, width, depth, slope gradient, sinuosity index), morphologic (architectural elements and configuration) of canyons, their downward evolution and we analyzed their internal structure in order to better understand their origin, construction mechanisms and evolution in relation with the regional geological context and their potentials subaerial systems.