Author/Authors :
Matoshko، نويسنده , , Andrei V. and Gozhik، نويسنده , , Piotr F. and Danukalova، نويسنده , , Guzel، نويسنده ,
Abstract :
This paper reviews the occurrence, structure, stratigraphy and development of the principal deposits of the Rivers Dniester, Dnieper, Don and Volga. Such archives occur as alluvial accumulations (infills, ‘sheets’ and fans/deltas), sometimes filling great buried incisions and giving rise, in the modern relief, to plains, valleys and terraces. These accumulations consist of alluvial suites, each with unique lithofacies characteristics. Correlation is based on marker beds from marine transgressions, waste mantles and glaciations, together with mammalian and molluscan biostratigraphy from the fluvial deposits themselves. Overprinted onto a background of predominant incision (typically 160–200 m), within the middle reaches of Dnieper, Don and Volga there are two complete major erosion/aggradation cycles between the Miocene and the late Middle Pleistocene, followed by a younger erosion phase that continues to the present. In contrast, within the Middle Dniester, one such cycle is recorded in the Late Miocene-Early Pliocene, followed by 250–270 m of incision. Most valleys served as arterial channels for intracontinental sediment transport but, where they coincide with ancient rift zones, they represent basins of alluvial accumulation. Neotectonic movements, the dynamics of which have differed between the East European Platform and the transitional zone between this platform and the Carpathian Orogenic Belt, probably controlled the general incision and erosion/aggradation cycles. Climatic oscillations, however, have influenced the structure and composition of the alluvial suites.
Keywords :
Pleistocene , Miocene , fluvial deposits , Quaternary , Pliocene