Continental margin topography at the South-East of the Black Sea

Abstract

At the continental margin of the south-eastern Black Sea (near Georgian coasts) the continental shelf, continental slope and continental rise are highly dissected with submarine canyons and valleys. Some bathygraphic systems can be outlined where submarine canyons change into submarine valleys and further into deep sea channels of turbidity currents. Some morphometric data are given for largest submarine canyons and valleys, topography of their deep-sea parts being discussed. The presence of sand and gravel in the cores at the submarine valleys thalwegs (against the background of prevailing mud) confirms the conclusion about significance of turbidity current in the process of debris transport and modeling of continental rise topography in the region studied. The double nature of submarine canyons and valleys is emphasized-first, they are large erosional forms, second, and they are ways of debris transport to lower levels. The continental rise at the South-East of the Black Sea is proved to be an individual morphological unit, representing an accumulative apron formed with many coalesced fans of submarine canyons.