摘要
用γ分析方法对采自云南滇池沉积孔柱中的天然放射性核素２１０Ｐｂ、２２６Ｒａ和人工放射性核素１３７Ｃｓ、２４１Ａｍ的垂直剖面特征及相应沉积年代进行了研究。并且用２１０Ｐｂ法计算了近百年来该地沉积速率的变化和各采样层位的沉积年代。对计算结果用人工放射性核素１３７Ｃｓ和２４１Ａｍ时标法进行了验证。研究结果表明该地湖泊沉积演化过程受到较强的人类活动的影响。
Sediment samples from Dianchi Lake sediment core were measured by means of the direct γ ray analysis for the sediment-depth profiles of natural radionuclides 210 Pb and 226 Ra and artificial radionuclides 137 Cs and 241 Am. The 226 Ra activity provides a direct measurement of supported 210 Pb activity for each sample analyzed, and the 137 Cs and 241 Am activity may provide independent age markers. The sediment core was dated with 210 Pb by using a constant rate of supply(CRS) model and the results were consistent with additional dating evidences from the artificial fallout nuclides 137 Cs and 241 Am. The study indicates that the sediment accumulation rates of Dianchi Lake were varied significantly during the past 100 years and had an accelerated accumulation rate in recent several years.
出处
《核技术》
EI
CAS
CSCD
北大核心
1997年第2期100-104,共5页
Nuclear Techniques
基金
国家自然科学基金
中国科学院专项支持项目"中国湖沼的系统调查与分类研究"共同资助
