Three decades of dating recent sediments by fallout radionuclides: a review
Three decades of dating recent sediments by fallout radionuclides: a review
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DOI：
10.1177/0959683607085598
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发表时间：
2008-01-01
期刊：
影响因子：
2.4
通讯作者：
Appleby, P. G.
中科院分区：
文献类型：
--
作者：
Appleby, P. G.
本文回顾了自20世纪70年代中期弗兰克·奥德菲尔德在利物浦大学开展的铅-210测年计划以来的30年时间。利物浦的工作包括研究控制向各种自然档案供应铅-210的基本程序，以及制定详细和系统的方法来确定这些档案中的环境记录的年代。使用英国40多年来雨水中铅-210浓度的数据和一个简单的大气模型来检验这一假设，即在任何给定地点测量一年或更长时间的时间尺度时，铅-210降落物是恒定的，并开发了一个简单的大气模型，以解释在大片陆块上观测到的通量的空间变化。CRS测年模型的基本假设已通过对流域/湖泊系统中放射性沉降物的质量平衡研究以及一般情况下使用大量单独研究的数据进行了详细的检验。用利物浦的数据库说明了铅-210测年方法的广泛适用性。结果显示，湖泊的大小从很小到很大不等，沉积速度从很快到很慢不等。讨论了沙漠湖泊和极地大气通量很低地区的沉积物记录测年的特殊困难，在某些情况下得出了意想不到的结果。
This paper reviews the Pb-210 dating programme carried out at the University of Liverpool over a period of three decades since its inception by Frank Oldfield in the mid-1970s. The work at Liverpool has included studies of the basic processes controlling the supply of Pb-210 to the various natural archives, as well as the development of a detailed and systematic methodology for dating the environmental records in these archives. The assumption that Pb-210 fallout at any given location is constant when measured on timescales of a year or more has been tested using data on Pb-210 concentrations in UK rainwater spanning more than 40 years, and a simple atmospheric model developed to account for observed spatial variations in the flux over large land masses. The basic assumptions of the CRS dating model have been tested in detail using mass balance studies of fallout radionuclides in catchment/lake systems, and in general using data from a large number of separate studies. The Liverpool data base is used to illustrate the wide ranging applicability of the Pb-210 dating method. Results are shown from lakes varying in size from the very small to the very large, and with sedimentation rates ranging from the very fast to the very slow. The particular difficulties of dating sediment records from Desert Lakes and Polar Regions with very low atmospheric fluxes are discussed, with unexpected results in some cases.