Black Sea Basin: Sediment Types and Distribution, Sedimentation Processes

The paper presents a part of the scientific activity of GEOECOMAR team during the IAEA project RER 2/003 Marine Environmental Assessment of the Black Sea Region, on board of R/V “Prof. Vodyanitskyi” and in laboratories. The Black Sea presents different sedimentological and geochemical characteristics in the eastern and western sub-basins. Whole sections of the Upper and Middle Holocene sediments were revealed in most cores recovered from the whole Black Sea basin. Scientific methods (grain size, X ray investigations, rate of sedimentation and radiogenic measurements, geochemistry characteristics of water and sediments) showed the general distribution of the bottom sediments, at the surface and downward, synand postdepositional sedimentary structures, lithological and geochemical compositions. As a result of detailed sedimentological studies in the whole Black Sea basin, for the first time a complete picture of the current grain size composition in the Upper Holocene sediment sections, was obtained. The data show that the deposits were accumulated in rather variable lithodynamic conditions (e.g. shelf, continental rise, abyssal plain). Processes of redeposition (e.g. turbiditic currents) have played an important role. At some stages "zero sedimentation" dominated, and during other periods scanty terrigenous material was accumulated.