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Ice scours are formed when the keels of floating icebergs or sea ice hummocks penetrate unlithified seabed sediments. Until now, ice scours have been divided into “relict” and “modern” according to the water depth that corresponds with the possible maximum vertical dimensions of the keels of modern floating icebergs. However, this approach does not consider climatic changes at the present sea level, which affect the maximum depth of ice keels. We present an application of 210Pb dating of the largest ice scour in the Baydaratskaya Bay area (Kara Sea), located at depths of about 28–32 m. Two sediment cores were studied; these were taken on 2 November 2021 from the R/V Akademik Nikolay Strakhov directly in the ice scour and on the “background” seabed surface, not processed via ice scouring. According to the results of 210Pb dating, the studied ice scour was formed no later than the end of the Little Ice Age. Based on the extrapolation of possible sedimentation rates prior to 1917 (0.22–0.38 cm/year), the age of the ice scour is estimated to be 1810 ± 30 AD. The mean rate of ice scour filling with 70 cm thick sediments from the moment of its formation is around 0.33 cm/year.

The paper reviews the study results of sedimentation and formation of geochemical characteristics of glacial Lake Bretjørna sediment – as the example of postglacial process in inner areas of Arctic archipelagos. Field research and sampling were carried out in the winter of 2018. The properties of sediments along the profile of the lake were analyzed. The income and accumulation of heavy metals in sediment were assessed. The lithofacies characteristics of the sediments and their spatial distribution were determined. In the paper the main geochemical characteristics of the lake bottom sediments (granulometric composition, organic matter content, as well as the accumulation of Pb, Zn, Cu, Ni, Fe, Mn, Hg) are considered. The correlation between the lithological composition of sediments and their micro-component content are shown. Correlation between elements and terrigenous sediments income from Northern Scandinavia and the Kola Peninsula accumulated by the glacier and snow cover of the catchment is obtained. Three associations of trace elements in the group of studied elements are distinguished.

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