The paper examines the results of long-term monitoring studies of the physicochemical properties of Holocene silts in Kandalaksha Bay of the White Sea. Based on a comprehensive analysis of the ratios of the natural moisture content (Wn), moisture content of the liquid (upper plasticity) limit (WL), and organic carbon content (Corg) for the depth of marine organomineral bottom sediments, it is concluded that the sediments can be separated by physicochemical indicators by introducing the sediment transformation index (Ist). Analysis of the distribution of sediment properties in terms of depth carried out in other water areas (e.g., in the Laptev Sea) suggests the universality of this indicator.