This paper deals with the processes of recent sedimentation within the major depression of the Arctic continental margin-the St. Anna Trough. Based on detailed studies of the surface layer of the bottom sediments (0-3 cm), the dynamics of the sedimentation is assessed and the fine features of the transformation of the grain-size structure of the sediment in the course of its migration and burial are shown. Four dynamical zones are distinguished: zones of abrasion, transit, accumulation, and transit/accumulation. Sources of the recent sedimentary matter are determined. The above-mentioned dynamical zones are important for forecasting the sites of possible pollutant accumulation, which is especially urgent in relation to the exploration of the hydrocarbon fields discovered on the West Arctic shelf of Russia.