Engineering-geological and geochemical conditions of polygonal landscapes on the Belyy Island (the Kara Sea)

The article deals with the factors determining engineering-geological peculiarities of the Belyy Island (the Kara Sea) such as wide spread of polygonal landscapes and special geochemical background (salinization of soils and ice wedges, presence of cryopegs). The soil temperature changes over the last 40 years are traced. In 2009 the temperature of soils of the first marine terrace increased by 2,4°С in comparison with 1972. Ice wedges having the salinity of 816-1240 mg/l were investigated within the first terrace, but ultrafresh ice wedges with the salt content of 36-45 mg/l were also found. The high mineralization is explained by local influence of the saline lakes. The ice wedges within the marshes are less mineralized (60-268 mg/l). The most significant mineralization is observed in cryopegs. It is more than 110 g/l that is much more than in the seawater. The authors conclude that the high mineralization and stable sodium-chloride composition indicate ice wedge subaqueous syngenetic accumulation during changing facial and climatic conditions.