Physically-based-dating for pond sediments

池塘沉积物的物理性质分析表明，在1964年发生过暴雨的流域，沉积物的粒度序列中可以追踪到物质运动的残余;由于暴雨而发生物质运动的年份在粒度分布中表现为显著的粗化。用^ Cs浓度估算了时间<137>;三个池塘沉积物序列的浓度峰值（1962年左右）被认为处于同一沉积环境阶段，每个地区池塘的粒度变化趋势相似，具有相似的沉积和/或水侵蚀条件。用~（137）Cs计算的近30年来各采样池中心的平均沉积速率与各流域的地貌背景密切相关。

Analyzes of physical properties in pond sediments show that the remnant of mass movements can be traced in the grain-size sequences of sediments in the drainage areas where there have beeen heavy rainfalls in 1964 ; the years of mass movements due to heavy reinfalls show up as prominent coarsening in the grain-size distribution. The date is estimated with the ^<137>Cs concentration ; the peaks (about 1962) in the concentration of sediment sequences from three ponds are assumed to be in the same phase of sedimentary environment.Grain size variations in the ponds in each area show similar tendency ; there have been similar sedimentary and/or hydro-erosional conditions. Average sedimentation rate during past 30 years in the center of sampling ponds, which can be calculated by the use of 137Cs, is closely related to geomorphological settings in each drainage basin.