【摘要】 太湖THS沉积物柱状岩心中存在3个明显的137Cs蓄积峰,高含水率和有机质含量是前苏联切尔诺贝利核电站核泄漏对应的137Cs蓄积峰向表层迁移的一个可能的原因。利用137Cs核素1963年和1975年对应的蓄积峰计算出沉积速率为0.34 cm/a。利用137Cs核素1963年对应的蓄积峰进行校正,采用210Pb计年的CRS模式获得不同时段的沉积速率,发现在80年代末沉积物堆积通量最高,达到0.6 g/(cm2.a)。两种计年方法的结合有助于认识沉积速率的变化情况。更多还原

【Abstract】 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.更多还原