Figure 2 Activity concentrations of 210Pbtot, 226Ra, 228Ra and 228Th (Bq kg-1 dw) in sectioned (0-1, 1-3 and 3-6 cm) sediment cores from stations GRA11, GRA15, GRA16 and GRA17. Results below detection limits are shown as open circles. Average depths of each section are plotted. Analytical uncertainties are given as ±2σ .
