| 利用210Pb、137Cs和241Am计年法测算云南抚仙湖现代沉积速率 |
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| 引用本文： | 王小雷,杨浩,赵其国,魏荣菲.利用210Pb、137Cs和241Am计年法测算云南抚仙湖现代沉积速率[J].湖泊科学,2010,22(1):136-142. |
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| 作者姓名： | 王小雷 杨浩 赵其国 魏荣菲 |
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| 作者单位： | 南京师范大学地理科学学院, 南京 210046,南京师范大学地理科学学院, 南京 210046,南京师范大学地理科学学院, 南京 210046;中国科学院南京土壤研究所, 南京 210008,南京师范大学地理科学学院, 南京 210046 |
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| 基金项目： | 国家自然科学基金项目(40873071);博士学科点专项基金项目(2007105SBJ0150);南京师范大学优秀博士学位论文培育基金项目(1243211601039)联合资助 |
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| 摘 要： | 通过对云南抚仙湖沉积物柱芯样品的210Pb、137Cs和241Am测试表明，柱芯剖面上有明显的1963年和1986年137Cs蓄积峰，验证了1975年次级蓄积峰存在的可能性，这些峰形完好的蓄积峰对抚仙湖的现代沉积环境有明显的时标意义。利用137Cs计年法得到抚仙湖沉积物自1963年、1975年及1986年以来到2007年的平均沉积速率分别为0.063g/(cm2·a)、0.052g/(cm2·a)和0.039g/(cm2·a)，说明了过去近五十年抚仙湖沉积速率整体上经历了一个由快到慢的过程。借助于241Am 的1963年蓄积峰可以提高137Cs计年的准确性。根据210PbCRS计年模式，计算出每个样品深度所对应的年代，与137Cs计年法比较存在一定的偏差，分析了两种计年方法存在差异性的原因。通过质量深度和年代分析，抚仙湖的沉积速率变化幅度比较大，表明抚仙湖近129年来的沉积环境不稳定，可能与相应历史时期的人类活动有密切的关系。
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| 关 键 词： | 环境放射性核素( class="?ùê?1"> class="?ùê?1 210Pb、137Cs和241Am)" target="_blank">">210Pb、137Cs和241Am) 抚仙湖 沉积速率 人类活动 |
| 收稿时间： | 2009/3/26 0:00:00 |
| 修稿时间： | 5/7/2009 12:00:00 AM |
Radionuclide dating(210Pb,137Cs,241Am)and modern sedimentation rate in Lake Fuxian |
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| WANG Xiaolei,YANG Hao,ZHAO Qiguo and WEI Rongfei.Radionuclide dating(210Pb,137Cs,241Am)and modern sedimentation rate in Lake Fuxian[J].Journal of Lake Science,2010,22(1):136-142. |
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| Authors: | WANG Xiaolei YANG Hao ZHAO Qiguo and WEI Rongfei |
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| Institution: | College of Geography Science,Nanjing Normal University,Nanjing 210046,P.R.China,College of Geography Science,Nanjing Normal University,Nanjing 210046,P.R.China,College of Geography Science,Nanjing Normal University,Nanjing 210046,P.R.China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,P.R.China and College of Geography Science,Nanjing Normal University,Nanjing 210046,P.R.China |
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| Abstract: | 210Pb, 137Cs and 241Am were used to analyze the sediment core of Lake Fuxian. In the core, there were obvious peakscorresponding to 1963 and 1986, verifying the existence of peak recorded in 1975,which was important age mark for the Lake Fux-ian sediment. The sedimentation rate of the Lake Fuxian was 0.063g/cm2.a by 137Cs time marker(1963),0.052g/cm2.a by137Cs time marker(1975)and 0.039/cm2.a by 137Csyears. 241Am dating can improve the accuracy of peak in 1time marker(1986),which indicated a slower process in the past 50auPh(CRS) dating showed a little deviation from 137Csexplaining the reasons in different viewsThe limit mass depth was 7.366g/cm2.a,which corresponded to the age of 1878 dating The average sedimentation rate from 1878 to 2007 was 0.057/cm2.a,which was changeable in the Lakc h'uxian by analyzing the massages, which showed that the sedimentation environment was related to human disturbance in the depth and past 129 years. |
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| Keywords: | Radionuclide(210Pb 137Cs 241Am) Lake Fuxian sedimentation rate human disturbanr e |
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