Characterization of 210Pb and 137Cs radionuclides in sediment from Lake Shinji, Shimane Prefecture, western Japan

By using the sequential extraction technique, most of 214Pb, 137Cs and 40K were proved to be contained in silicate fraction. A part of 210Pbex presumably existed as carbonate and iron manganese oxides for coarser grains, and as iron manganese oxides for finer grains, in addition to silicate fraction. Although 210Pb and 137Cs may occupy the different sites and exist in different chemical phases, the bulk contents in the samples from a variety of locations within the same lake showed a generally good correlation. This result suggests their similar depositional process within a lake in a macroscopic view, being one of the evidences for the validity of sedimentation chronology in the field.