Younger Dryas–Preboreal transition documented in the fluvial environment of Polish rivers

The rapid climatic change at the Younger Dryas–Preboreal transition has been documented in the sequence of annually laminated sediments of Lake Go ci in the middle course of the Vistula Valley. The author correlates this key profile with about 50 localities of alluvial sediments and abandoned channels in the Vistula and Warta catchments. Discussed deposits have been radiocarbon-dated. The interpretation is supported by pollen diagrams. It is concluded that in most cases, either abundance of large paleochannels or a change from channel to overbank facies or to organic sedimentation took place just at the transition time. Also, in the fills of the Late glacial paleochannels, a decline in fluvial activity is observed that is evidenced by a change in grain size composition. However, an exact dating of this rapid transition is difficult as it coincides with the radiocarbon plateau at 10 ka BP.