Paleolimnological research at the Institute of Limnology RAS in the last decade – the lithostratigraphic aspect

The article presents the results of studies on the dynamics and features of late- and post-glacial sedimentation in lakes of a number of geographical regions of the north-west and north of European Russia: in Lake Ladoga, in small lakes of the Ladoga region, the Karelian Isthmus and the White Sea region. The identified features of sedimentation in these lakes made it possible to advance in solving such important paleogeographic problems as detailing the chronology of the Baltic-Ladoga Holocene connection, establishing the maximum level of the Ladoga transgression, establishing the time of maximum biological productivity in lake ecosystems in the Holocene, the chronology of the relative sea level changes in the White Sea region in the Holocene. The time when organic accumulation began in small lakes in the northern part of the Karelian Isthmus, located in the path of the Heinjoki paleo-strait, was determined as 3000– 3500 cal. BP. It was revealed that the establishment of lacustrine sedimentation environments in the basins of these lakes proceeded gradually. The structure of sediments in small lakes in the Ladoga region was found to have fundamental differences depending on their altitude and spatial position. The stages of Holocene organic matter accumulation in the sediments of Lake Ladoga were identified. The time period of maximum accumulation of organic matter was determined in the range of 5200–9500 cal. BP. The White Sea shoreline displacements in the Holocene in various areas of the coast have been reconstructed. It has been established that in lakes of the Solovetsky archipelago, located at 22–35 m above sea level, lacustrine sedimentation started at 10 500–11 000 cal. BP.