Geology, geography and global energy

Scientific and Technical Journal

Neotectonic deformation of the continental shelf near the upper reaches of the Danube canyon

2017. 3, pp. 56-65

Roginskiy Konstantin A. - C.Sc. in Engineering, P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, 36 Nakhimovskiy ave., Moscow, 117997, Russian Federation, roginskiy@list.ru

Yevsyukov Yuriy D. - C.Sc. in Geography, Leading Researcher, P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, 36 Nakhimovskiy ave., Moscow, 117997, Russian Federation, evsgeol@rambler.ru

Rudnev Valeriy I. - Junior Researcher, P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, 36 Nakhimovskiy ave., Moscow, 117997, Russian Federation, evsgeol@rambler.ru

The Southern Branch of the P.P. Shirshov Institute of Oceanology RAS has been organizing studies of the Black Sea bottom relief since 1971. Detailed investigation of bottom topography was carried out in about 50 areas on the continental margin intersected by manifold canyons. It was revealed that bottom relief characteristics in the studied areas demonstrate diversity and heterogeneity. A number of differences were found in canyon morphology in the south-eastern and north-western parts of the Black Sea. In the south-eastern part canyons are related to the young mountain systems (the Greater Caucasus, Pontic mountains), while in the north-western part they are related to the vast river valleys of the Dnieper, Southern Bug, Danube and other rivers, separated by small mountains and hills. It was found out that canyon evolution depends on geological and geographical characteristics of the region where they are located as well as on tectonic activity regime and a ratio between areas of shallow water and adjacent land. These features determine canyon evolution and serve as a base for canyon classification. It is resulted in difficulties for their investigation and a number of contradictions in interpretation of canyon origin and evolution. Researchers facing with these difficulties pay a particular attention to upper parts of canyons to understand their role in interception of suspended sediments moving along the shelf; to investigate sediment material compound resulted from canyon valley erosion; to study origin and evolution both upper canyon parts and canyons themselves. Unique bathymetric data were collected during single channel echo-sounding surveys carried out in two expeditions in the region of the Danube canyon. Cartographic documents and general bathymetric profiles were made on the base of these data. Morphometric characteristics of the upper part of the canyon, projected to a vertical plane clearly demonstrate an evidence of neotectonic deformations of the outer zone of the continental margin.

Key words: , , , , , , , , , polygon, echo sounding, bottom relief, shelf, continental slope, alluvial fan, canyon, neotectonics

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