in the Lake Bafa, Mugla, Turkey

The sediment chronology was determined using Lead-210 ( 210 Pb) and Cesium-137 ( 137 Cs) dating method. Profile distributions of Polonium-210 ( 210 Po) and 210 Pb were evaluated with regarding to sediment porosity, core location, bottom currents and prevalent winds. Max. 210 Po and 210 Pb activity concentrations are found as 193.83 ± 4.43 and 187.84 ± 4.84 Bq kg -1 respectively. According to vertical radionuclide ( 210 Po/ 210 Pb) ratios, sediments especially in east part of the lake are rich with respect to the fecal pellets. Residence time of the 210 Pb is calculated as 1.9 months in the lake. Average sedimenta- tion rate (0.359 ± 0.012 cm year -1 ) in central area is higher than the near shore (0.137 ± 0.006 cm year -1 ) one in Lake Bafa.