Late Pleistocene stratigraphy and sedimentary environments of the Severnaya Dvina‐ Vychegda region in northwestern Russia

• Published in: Boreas
• Main Authors: Lyså, Astrid, Larsen, Eiliv, Buylaert, Jan‐Pieter, Fredin, Ola, Jensen, Maria A., Kuznetsov, Denis, Murray, Andrew S., Subetto, Dmitry A., van Welden, Aurelien
• Other Authors: Geological Survey of Norway
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Dammed Lake; Severnaya Dvina; Vina; dvina; Ice; permafrost
• Online Access: http://dx.doi.org/10.1111/bor.12080; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12080; https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12080

The L ate P leistocene stratigraphy from the S evernaya D vina‐ V ychegda region of northwestern R ussia is revised based on investigations of new localities, revisiting earlier localities, introduction of about 110 new OSL dates and burial depth corrections of earlier published OSL dates, in addition to six new radiocarbon dates. Most of the OSL samples studied here are from fluvial and subaquaeous sediments, which we found to be well bleached. Six chronostratigraphical units and their sedimentary environment are described, with the oldest unit consisting of pre‐ E emian glacial beds. For the first time, Early W eichselian sediments are documented from the region and a fluvial environment with some vegetation and permafrost conditions is suggested to have persisted from the end of the E emian until at least about 92 ka ago. The period in which a M iddle W eichselian W hite S ea L ake could have existed is constrained to 67−62 ka, but as the lake level never reached the thresholds of the drainage basin, the lake probably existed only for a short interval within this time‐span. Blocking and reversal of fluvial drainage started again around 21−20 ka ago when the F ennoscandian I ce S heet advanced into the area, reaching its maximum 17−15 ka ago. At that time, an ice‐dammed lake reached its maximum water level, which was around 135 m above present sea level. Drainage of the lake started shortly after 15 ka ago, and the lake was emptied within 700 years. Severe periglacial conditions, with permafrost and aeolian activity, prevailed in the area until about 10.7 ka.