The article examines the features of the transition zone from the deep-water to the shallow-water part of the Kandalaksha Bay of the White Sea, which is represented by a ridge of heterogeneous (structural, glacial, and water-glacial) origin. The materials are based on new data obtained through continuous seismic-acoustic profiling (CSP). Multi-channel high-frequency modifications of seismic equipment were used. This allowed to execute a more detailed seismic-stratigraphic division of the thicknesses of subglacial (glacio-lacustrine and glacio-marine) and marine nepheloid deposits. In particular, three horizons were distinguished in the thickness of layered supraglacial sediments by textural features. They reflect the evolution of primary glacial-lake basin into glacial-marine. Large ice-proximal fans with high sediment thickness are distinguished in the upper part of the ridge. These fans mainly formed the relief of the studied ridge. These and other obtained data allow us to raise the question of the transformation of the continental glacier into a shelf glacier in a certain period of time within the process of degradation of the Scandinavian glacier. The wide development of modern geodynamic movements, significantly affecting the nature of the bottom relief and the accompanying gravitational processes, is shown. Stepped relief, alternation of local basins of Holocene nepheloid accumulation, separated by relatively steep slopes lacking sedimentary cover, are associated with these movements. Seismotectonic phenomena were a trigger for gravitational processes, which are also clearly visible on seismograms. The obtained materials allow for a substantial detalization of the paleogeographic conditions in the Late Pleistocene-Holocene, in particular, to more fully characterize the stage of environmental evolution from the glacial conditions to the glacial-marine and marine.