宇宙成因核素^(10)Be的地球化学行为及其在黄土示踪研究中的应用  

Studies on the geochemistry behaviors of cosmogenic nuclide ^(10)Be and its applications in loess tracing

作　　者：胡苗[1,2,3] 鲜锋[1,2] 武振坤[1,2] 周晓龙[1,2,3] 

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075 [2]陕西省加速器质谱技术及应用重点实验室,西安710061 [3]中国科学院大学,北京100049

出　　处：《地球环境学报》2013年第1期1197-1207,共11页Journal of Earth Environment

基　　金：国家自然科学基金项目(41230525;41203019);中国科学院重点部署项目(KZZD-EW-04)

摘　　要：^(10)Be是一种典型的长寿命宇宙成因核素,对其在自然界中的分布规律、迁移形式和赋存状态等地球化学行为特征的研究,是利用沉积物^(10)Be记录进行定年和环境示踪研究的理论基础。其中明确^(10)Be在不同沉积物中的赋存状态是研究^(10)Be保存性的基础,而^(10)Be在固相和液相介质中的分配系数Kd则主要反映了^(10)Be在固相和液相中的迁移能力,对研究自然界不同沉积物中^(10)Be的迁移性至关重要,直接影响到沉积物中^(10)Be环境示踪研究的有效性。本文尝试总结了大气成因^(10)Be在海洋、河流沉积物和土壤中的赋存状态,分析了^(10)Be分配系数Kd的分布范围及其主要控制因素。在此基础上以土壤中^(10)Be的分布特征、迁移规律及影响因素研究为参考实例,对比分析了目前已有对黄土-古土壤序列中^(10)Be地球化学行为研究取得的主要成果,建议未来应从地球化学机制方面进一步加强对黄土地层序列^(10)Be分布特征、浓度变化规律及可能影响因素的综合研究,为黄土^(10)Be示踪研究提供更全面的理论依据。The geochemical study of ^10Be, a typical long-lived cosmogenic distribution, migration and speciation, is the theoretical basis of ^10Be dating radioactive nuclide, such as and environment tracing. To determine the chemical states of ^10Be in different sediments is the foundation of the study of ^10Be preservation, and the partition coefficient of ^10Be is essential in the study of mobility of ^10Be in different sediments, which directly affects the validity of ^10Be environmental tracing. In this article, we summarized the study of the chemical states and distribution of the cosmogenic nuclide ^10Be in marine sediments, fluvial sediments and soils. We also analyzed the main factors that affect the ^10Be partition coefficient. On the basis of the above analysis, we introduced the study of the distribution characteristics and the migration laws of ^10Be as well as the controlling factors behind those laws in soil as a concrete example. Compared with that in soil, major achievements of geochemical behavior study of ^10Be in loess-paleosol sequence were also introduced. To provide more comprehensive theoretical support for the study of loess^10Be tracing, we should improve the research in geochemistry mechanisms of ^10Be distribution characteristics, concentration variation and influencing factors in loess stratigraphic sequence in future work.

关 键 词：宇宙成因核素^10Be 地球化学行为 黄土 示踪 

分 类 号：P597[天文地球—地球化学]