Paleogeography and Natural Environment of the Karelian Coast of the White Sea in the Holocene According to the Study of Lake Sediments Near the Mouth of the Keret River

Abstract

The article presents the results of a comprehensive (diatom and spore-pollen analysis and 14C-dating) study of the Holocene bottom sediments of a lake located on the coast of the Kandalaksha Bay of the White Sea near the mouth of the Keret River. Three stages in the development of the lake basin have been identified: marine, transitional, and lacustrine. Diatom assemblages characteristic of each facies are given. The indicator value of pollen, spores and non-pollen palynomorphs for identifying marine, transitional and freshwater sedimentation conditions is noted. A decrease in sea level was established at the turn of 7200 calendar years ago. The change of the marine environment of sedimentation to the lacustrine was recorded approximately at the turn of 6700 calendar years ago. For a given time, the position of the coastline of the sea is shown within the studied coast. The data of spore-pollen analysis were used for relative dating of post-glacial deposits. Vegetation was reconstructed from the end of the early Holocene to the present.