成都盆地浅层土壤中砷来源的多元统计分析

对成都盆地3 061个浅层土壤样品以元素为变量进行砷回归分析,在回归模型的基础上进行R型因子分析,并选取因子载荷较大的元素作为特征元素组合。在结合元素地球化学性质、区域地质背景和因子得分等值线图的基础上,根据特征元素组合来研究砷的来源。研究结果表明:成都盆地浅层土壤中砷的来源有6种,其中龙门山一带晚三叠纪、侏罗纪、白垩纪沉积岩系和酸性岩浆岩及基性岩、超基性岩是成都盆地浅层土壤的主要来源。相对于后期人类作用而言,自然作用对成都盆地土壤中砷分布特征的影响占主导地位。

Multi-Analysis of Sources of Arsenic in the Surface Soil of Chengdu Basin

Factor analysis is applied to 3,061 samples of the surface soil of Chengdu basin after a progress of regression analysis,in which arsenic is used as dependent variable while other elements are used as independent variables.Elements with higher factor loading are selected to compose characteristic groups.On the basis of taking account of geochemical properties of elements,regional geology and factor score isopleth maps,the subsequent study is based on characteristic groups of elements to explore the sources of arsenic.Results of the study demonstrate that arsenic in the surface soil of Chengdu basin has approximately six kinds of sources,among which sedimentary series of post-Triassic,Jurassic and Cretaceous systems along Longmen orogenic belt and acid magmatic and basic-ultrabasic rocks in the area are three main sources.It is indicated that,compared with that of subsequent human activities,the influence of natural progress on the distribution of arsenic in surface soil of Chengdu basin is dominant.