In the report, on the basis of studies of the Quaternary cover of the Ladoga and Onega lakes and the White Sea carried out in the last decade, the question of the peculiarities of the formation of the first glacial lakes on the eastern periphery of the Baltic crystalline shield, the time of their deposition, and the peculiarities of sedimentogenesis is discussed. It is concluded that sediments of a specific type of sedimentation, which are formed everywhere in inland basins (seas and lakes) can be identified as a glacial-water formation specific to the glacial regions of the Earth.