Stratigraphy of alluvia and phases of the Holocene floods in the valleys of the Eastern Carpathians foreland

摘要

The studied sequences of alluvia in the catchments of the Upper Dniester, Seret and Prut Rivers record the occurrence of the Late Vistulian terrace and 3-4 levels of the Holocene terraces as well as several series of the alluvial fills and paleochannel systems dated at 11,800-10,700 BP (13,470 +/- 85 -12,600 +/- 40 cal BP), 10,500-9800 BP (12,740 +/- 60-11,220 +/- 15 cal BP), 8700-7500 BP (9625 +/- 65 -8350 +/- 20 cal BP), 5500-5100 BP (6295 +/- 10-5845 +/- 75 cal BP), 3100-2700 BP (3310 +/- 30 -2800 +/- 40 cal BP), 2100-1700 BP (2060 +/- 55-1590 +/- 30 cal BP), Middle Ages, Little Ice Age and the last 150-200 years. The distinguished alluvial fills and flood phases in the valleys of the Eastern Carpathian foreland record, similarly to the valleys of the Upper Vistula River catchment in the Western Carpathian foreland, rhythmic changes in the precipitation (climate humidity) and hydrological regime, as well as an increasing human impact (deforestation and cultivation) during the last two thousand years. These changes are recorded in the sequences of floodplains by an increase in number and deposition rate of the overbank (sand-silt) series. Simultaneously, these changes are visible in pollen diagrams recording deforestation phases in floodplains (Neolithic Period, Roman Period and Middle Ages). (C) 2015 Elsevier Ltd and INQUA. All rights reserved.