摘要
本文通过对采自海南岛洋浦港、福建厦门外港、浙江象山港三个河口港湾的六个沉积柱样的１３７Ｃｓ分析，分别用１３７Ｃｓ剖面的最大峰值层及１３７Ｃｓ剖面的起始值层位估算了该六个站位的现代沉积速率，结果表明：在河口港湾沉积环境条件下，用１３７Ｃｓ剖面来估算沉积物的平均沉积速率是可行的，由１３７Ｃｓ最大值法，这六个站位的平均沉积速率分别为１．１４ｃｍ／ａ、１．５６ｃｍ／ａ、０．８２ｃｍ／ａ、０．７５ｃｍ／ａ、１．２６ｃｍ／ａ、１．６６ｃｍ／ａ，由１３７Ｃｓ最大值法得出的平均沉积速率其精确度与可信度要好于１３７Ｃｓ起始值得出的平均沉积速率。与２１０Ｐｂ法所得的结果符合的很好。１３７Ｃｓ起始值层位与预期值偏离的大小可以为我们提供有关该站位沉积环境、扰动作用强弱的信息。在应用１３７Ｃｓ剖面估算沉积速率时，还要注意沉积结构变化的影响。
Six sediment cores ,collected in Yangpu Harbour on Hainan Island ,Out of Xiamen Harbour in Fujian Province and Xiangshan Harbour in Zhejiang Province,were analyzed for Cs-137 activity,both the position of the peak (corresponding to the period of maximum deposition) and the position of the horizon(corresponding to the first appearance of Cs-137 in the environment)were been used to determine sedimentation rates.The results showed that it is possiable to use the Cs-137 profile to determine sedimentation rate in estuaries,Rates for these cores based on the position of peak of Cs-137 profile were 1.14cm/a,1.56cm/a,0.82cm/a,0.75cm/a,1.26cm/a,respectively.1.66cm/a,which are in good agreement with that based on Pb-210 dating and rates based on the occurrence of the horizon were larger than that based on Pb-210 dating,Nhieh this indicates physical mixing or reworking of seidments in estuaryies.
出处
《沉积学报》
CAS
CSCD
北大核心
1997年第4期67-71,共5页
Acta Sedimentologica Sinica
基金
南京大学海岸与海岛开发国家试点实验室资助项目
