The210Pb and137Cs profiles in sediment cores from Bay of Quinte, Lake Ontario

Abstract

210Pb,226Ra and137Cs profiles have been measured for sediment cores from three locations in Bay of Quinte, Lake Ontario, Canada. Compaction of the sediment with depth of burial is taken into account in calculating recent sedimentation rates and age profiles at these locations from the excess210Pb profiles. The rates are 1.803+0.592 cm·y−1 (0.254±0.083 g·cm−2·y−1), 0.101±0.017 cm·y−1 (0.036+0.006 g·cm−2·y−1), and 0.795±0.218 cm·y−1 (0.076±0.021 g·cm−2·y−1). The corresponding fluxes of excess210Pb to sediment/water interface are determined to be 1.652, 0.253, and 1.123 pCi·cm−2·y−1, respectively. The anomalies observed in the radionuclide concentration profiles are attributed to physical mixing. It is postulated that the significantly higher flux of210Pb observed at one of the locations is due to inputs from Trent River which joins the Bay near this location.