Luminescence ages of sediments from the margin of the penultimate glaciation in the north-eastern East European plain

Abstract

In this study we apply optically stimulated luminescence and infra-red stimulated luminescence to the sediments from the interfluve dividing three river basins: the Pechora, the Kama and the Severnaya Dvina, hoping to gather new age data on glaciofluvial sediment. We also studied the valley of the Berezovka, a medium-scale river cutting through this interfluve. We obtained a chronology from 17 quartz and 15 feldspar ages. Sedimentological analyses and luminescence dating show that most of the sediments examined here are water-transported (gully alluvium, slopewash deposits), and their ages mark a period of accumulation during MIS 2. Some of these sediments were reworked by aeolian processes; these took place over a time span consistent with such processes in other parts of the East European Plain (19-12 ka). The Berezovka river experienced incision before ∼22 ka and another erosion event with extremely high floods at 15–16 ka. Its terrace formed in MIS 5, constraining the minimum age of the valley. In the bottom part of the sections, much older, possible MIS 8, glaciofluvial sediments were found; the apparent absence of MIS 6 sediments may argue for moving the MIS 6 ice sheet limit further to the north of the study area.