Geochronology of the southern Baltic Sea sediments derived from 210Pb dating

Based on the vertical distribution of Pb-210 activity concentrations in bottom sediment, linear accumulation rates (LAR) and mass accumulation rates (MAR) were determined for 31 locations in the southern Baltic Sea region by applying models: Constant Flux Constant Sedimentation Rate (CF:CS) and Constant Rate of Supply (CRS). The dating of sediment layers in selected locations was also carried out. The reliability of the results was verified using radiotracers: Cs-137 and, for the first time, Sr-90. The results obtained were the basis for the development of maps of continuous distributions of LAR and MAR values in the areas where a particular type of bottom sediments were found: silt-clay, sandy silt, silty sand and mixtites covering the region of the southern Baltic. The maps constitute a tool supporting basic and applied research. Data for marine open areas were supplemented with sediment accumulation rate data for the areas of the Szczecin Lagoon and the Vistula Lagoon. The linear accumulation rates of bottom sediments of the southern Baltic varied from 0.61 to 3.54 mm y (-1) while mass accumulation rates ranged from 390 g m(-2) y(-1) to 910 g m(-2) y(-1), largely reflecting the LAR values.