| 引用本文: | 徐经意,万国江,王长生,黄荣贵,陈敬安.云南省泸沽湖、洱海现代沉积物中210Pb,137Cs的垂直分布及其计年.湖泊科学,1999,11(2):110-116. DOI:10.18307/1999.0204 |
| XU Jin-yi,WAN Guo-jiang,WANG Chang-sheng,HUANG Rong-gui,CHEN Jing-an.Vertical Distribution of 210Pb and 137Cs and Their Dating in Recent Sediments of Lugu Lake and Erhai Lake, Yunnan Province. J. Lake Sci.1999,11(2):110-116. DOI:10.18307/1999.0204 |
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| 摘要: |
| 云南省沪沽湖、洱海210Pbex的垂直分布受 Fe、Mn循环下210Po和210Pb沉积后再迁移的影响,分别表现为三种不同的剖面分布特征.210Pbex计年的沉积物堆积速率分别为0.050-0.051g·cm-2a-1和0.044-0.045g·cm-2a-1,反映百年时间尺度上的堆积结果.沪沽湖、洱海137Cs的垂直剖面分布虽然受分子扩散作用的影响,但并没有改变其峰值位置.沪沽湖深水湖区137Cs计年的沉积物堆积速率为0.045 ± 0 004g·cm-2a-1(1964年时标).按不同时标,洱海137Cs计年的沉积物堆积速率为对.048±0.0039·cm-2a-1(1964年时标),0.047 ± 0.0029·cm-2a-1(1975年时标),0.046±0 005g·cm-2a-1(1986年时标).三种时标给出的沉积物堆积速率一致,其平均值为0.047±0.0029·cm-2a-1,与210Pbex计年方法获得的数值吻合. |
| 关键词: 210Pb 137Cs 沉积物堆积速率 泸沽湖 洱海 |
| DOI：10.18307/1999.0204 |
| 分类号: |
| 基金项目:国家自然科学基金(49773207,49894170,49333040) |
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| Vertical Distribution of 210Pb and 137Cs and Their Dating in Recent Sediments of Lugu Lake and Erhai Lake, Yunnan Province |
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XU Jin-yi, WAN Guo-jiang, WANG Chang-sheng, HUANG Rong-gui, CHEN Jing-an
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state Key Lob. of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002
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| Abstract: |
| Two plateau lakes (Lugu Lake and Erhai Lake) with different conditions are selected to show 210Pb geochemical behavior. 210Pb and 137Cs vertical profiles in sediments are measured by the Multichannel Analysis System (Caberra 100) in order to attain creditable sediment accumulation rates. By the Fe-Mn circulation, 210Pbex vertical distribution in the sediments of Lugu Lake and Erhai Lake shows three types of distribution characteristics. But this has no influence on the 210Pbex dating result. Sediment accumulation rates of Lugu Lake and Erhai Lake are 0. 050 -0.051 g·cm a and 0.044 -0.045 g· cm-2a-1 respectively by 210Pbex method which repsents the average sediment accumulation result on 100-year scale. The discrepancy between the 137Cs vertical distribution characteristics and the depositional fluxes is probably caused by the Cs diffusion in early-diagenesis process. However, the Cs diffusion does not change the location of Cs peaks. Sediment accumulation rate of Lugu Lake is 0. 045 土 0. 004g · cm-2a-1 by 137Cs time marker (1964), and that of Erhai Lake is 0. 048 ± 0. 003g·cm-2a-1 (1964), 0. 047 ± 0. 002g-cm-2a-1(1975), and 0. 046 ± 0. 005g· cm-2a-1(1986) respectively which reflects the average sediment accumulation result. |
| Key words: 2l0Pb 137Cs Sediment accumulation rate Lugu Lake Erhai Lake |
