Geochronology of sediment cores from the Vefsnfjord, Norway

The sedimentary environment is a repository and carrier for a variety of pollutants, and sediment transport from land to coastal areas is an important environmental process. In the present study, we use ²¹⁰Pb/²²⁶Ra and ¹³⁷Cs in sediment cores to assess sediment supply rates at four sites within the Vefsnfjord in Nordland county, Norway. This area was highly affected by fallout from the Chernobyl accident in 1986 and inventories of ¹³⁷Cs in the fjord are much higher than in many other Norwegian fjords. Sedimentation rates between 0.042 and 0.25 g cm^-2 y^-1 (0.060 and 0.38 cm y^-1) were determined using a combination of the Constant Rate of Supply (CRS) and Constant Flux:Constant Sedimentation rate (CF:CS) models. Well-defined ¹³⁷Cs concentration peaks were used as a supplementary tool to the ²¹⁰Pb dating methods.