Paleogeographic reconstructions of the natural environment on the Karelian coast of the White Sea (Sonostrov island area)

In the area of Sonostrov Island on the Karelian coast of the White Sea, using a complex of methods, including spore-pollen, diatoms, and radiocarbon ( 14 C), new data were obtained on changes in sea level over time. The results are based on a study of 3 lake basins located at absolute elevations from 29, 22 and 10 m above sea level (a. s. l.). During the work, a reconstruction of vegetation from the end of the Boreal period to the present was carried out. Based on lithological and micropaleontological characteristics, three stages of development of lake basins have been established: marine, transitional and lacustrine. New data shows that the sea coastline 6500 calibrated years ago (calibrated years ago) corresponded to an elevation of 29 m a. s. l. Over the next 200 years it dropped to 22 m, and around 1800 cal BP was at 10 m a.s.l. The rate of rise of the territory from 6500 to 6300 cal BP was 35 mm/ year and could be caused by tectonic processes and a decrease in the rate of eustatic rise of the World Ocean level. From 6300 to 1800 years ago the rise of the coastline slowed to 2.7 mm/year, but from 1800 cal. and to date it has increased to 5.6 mm/year.