QUATERNARY DEPOSITS AND GEOMORPHOLOGICAL FEATURES OF LAKE ONEGA

Many publications have been devoted to the geological and geomorphological study of both Lake Ladoga and Lake Onega – the largest lakes of Northwest Russia and Europe. The last comprehensive geological studies of Lake Onega were carried out by Polar Marine Geosurvey Expedition as part of a geological survey at a scale of 1: 500,000 [12] and by Finnish researchers [19] at the beginning of the 21st century. Subsequently, these data were included in the third-generation State Geological Map at a scale of 1:1 000 000 [13]. Study of the basin’s geological structure was resumed in 2016 by researchers from the Northern Water Problems Institute of the Karelian Research Center of the Russian Academy of Sciences, St. Petersburg State University, Lomonosov Moscow State University and Herzen State Pedagogical University of Russia, as well as representatives of other scientific organizations. The works included geological sampling, drilling from ice platform, seismoacoustic profiling and side-scan sonar. The aim of the works was to clarify data on the structural features of the Upper Pleistocene and Holocene deposits of Lake Onega and the genesis of the lake basin relief. Based on the data obtained in the course of field studies, a new distribution scheme of the Lake Onega Quaternary deposits was drawn up. Comparison of the scheme with the data on the bottom topography made it possible to characterize its genesis and draw up a geomorphological scheme. The data presented in this article can be used to update and supplement the State Geological Map of the Northwest Russia, as well as to solve other problems of Quaternary geology and paleogeography.