RECENT SEDIMENTATION OF THS CORE IN SOUTHERN TAIHU LAKE INFERRED FROM ¹³⁷Cs AND ²¹⁰Pb MEASUREMENTS

THS core was collected from southern Taihu Lake. Three distinct peaks of ¹³⁷Cs are observed in the core. Results of ¹³⁷Cs analyses indicate disturbance in the top surface. Up-core transference of ¹³⁷Cs peak of Chernobyl disaster is partially caused by high water content and organic matter in the sediment. Using depths recorded in 1963 and 1975 as the datum levels, the average sedimentation rate is calculated to be 0.34 cm/a. Corrected ²¹⁰Pb dates and sedimentation rates are calculated based on CRS model using the ¹³⁷Cs date in 1963 as a reference point. The results show that sedimentation flux rates are very high, reaching 0.6 g/cm·a around 1990s. The combination of these radionuclide dating methods is useful for us to understand the sedimentation process of the lake where sedimentation rates changed.