宇宙线散落核素~7Be在山区表土层中的分布特征及侵蚀示踪原理  

DISTRIBUTION OF COSMOGENIC ~7Be IN SURFACE SOILS OF MOUNTAIN REGION AND THE PRINCIPLES FOR EROSION TRACE

作　　者：白占国[1] 万国江[2] P.H.Santschi M.Baskaran 

机构地区：[1]中国农业科学院土壤肥料研究所 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002 [3]DepartmentofMarineSciences,TexasA&MUniversity,Galveston

出　　处：《土壤学报》1998年第2期266-275,共10页Acta Pedologica Sinica

基　　金：国家自然科学青年基金!49503049;国家自然科学重点基金!49333040;美国国家科学基金!US 82-50

摘　　要：宇宙线散落核素7Be具稳定的物质来源和53．3天的半衰期，提供了示踪环境微粒季节性迁移的必要条件；其在土粒中主要存在于Fe—Mn氧化物及有机质结合相，适应于季节性微粒迁移示踪；它在表土层中的垂直分布特征提供了示踪微粒季节性迁移的充分条件。7Be在表土层中的累计值、表观比活度、最大渗透深度及相对侵蚀（或堆积）速率是土粒迁移的示踪参数。Beryllium-7, a cosmogenic nuclide, has stable sources in origin and half-life of53.3 days, which provide essential conditions as a geochemical tracer for seasonalparticle transport in the environment. A major poition of 7Be (about 95%) in the soilsis bound to organic, Fe-Mn oxides and residual fractions. It can be removed with soilparticle transport and be used to trace soil erosion. The characteristics of 7Be verticaldistribution in the soil profiles provide sufficient evidence for trace of seasonal particletrsnsport. 7Be inventory, aPParent activity and maximum Penetrative depth in soil coresas well as relative erosion or accumulation rate can be taken as trace parameters forsoil erosion.

关 键 词：地球化学相 土层分布 示踪模型 土壤侵蚀 

分 类 号：S157[农业科学—土壤学]