【作者】 李振宁；

【导师】 栾文楼；

【作者基本信息】 石家庄经济学院 ， 矿产普查与勘探， 2010， 硕士

【摘要】 硒是人类生命活动所必需的微量元素。河北平原1/25万地质调查显示,河北平原土壤硒资源缺乏,但部分地区存在的硒元素异常。本文以河北省平原硒异常区为研究对象,进行了硒元素异常源的追踪和生态效应评价,为当地农业结构调整提供地球化学依据。《河北省农业地质调查》项目对河北省平原地区农田土壤进行了采样测试。根据土壤样品分析结果,作者对河北平原地质背景、土壤、地貌等各种因素进行综合分析,将河北平原划分为两大分区,11个土壤形成沉积环境区域。另外对各子区表层和深层土壤中硒元素的含量进行对比分析,并利用统计方法研究各分区中硒含量的分布特征,分析结果表明：河北省平原地区土壤硒元素整体含量低,分布差异较大,存在硒富集带,主要表现在唐山、保定、石家庄-邯郸的城市及周边地区。通过对该区域的深、浅层土壤样品分析数据的对比、利用X±nS(n=1.5-3)将数据进行迭代处理后,确定该地区的硒元素的异常下限。根据浅、深层土壤含量差异,Se元素地球化学背景,异常区剖面分析以及聚类分析进行了异常成因的分析,认为表层硒元素异常源主要与人为源关系密切,且主要为大气降尘,并估算出人为源于自然源输入比例为3：1。通过对研究区内岩石样品、土壤样品、灌溉水样、大气降尘、化肥样品中硒元素含量的分析,对硒异常来源作了初步的判断。研究认为河北平原深层土壤硒元素含量未受人为因素影响,主要受区域地质背景控制；表层土壤硒含量是在原有硒元素地球化学背景的基础上,经人为活动的影响在表层富集,并运用通量研究计算出河北平原硒元素主要的人为来源。通过讨论研究小麦、玉米籽实中硒元素与对应根系土硒元素全量及土壤理化性质的相关关系,并以此建立响应关系方程。依据建立的响应关系方程,利用研究区多目标地球化学调查数据,估算研究区每个点位上小麦、玉米籽实中的硒元素含量,从而对研究区内大宗农作物的安全性进行系统评价。根据土壤硒元素分级标准,对河北平原土壤进行分级,确定各级别土壤面积和比例,为河北省农业结构调整提供科学依据。更多还原

【Abstract】 As a kind of mecroelement,Selenium is necessary for human life and activities. 1/250000 geological survey in Hebei Plain shows that the content of Se in soil is low but it exists Se anomalous zone in some research areas. This Se anomalous zone in Hebei Plain is our research object. We carry out tracing of anomalous sources of Se and ecological effects evaluating and the purpose is to provide geochemical evidence for local agricultural structure adjustment.The program of "Hebei province agriculture geological investigation" carried on sampling test to farmland soil in plain area of Hebei province. According to the analytical result of soil samples, the author divides plain area of Hebei province into two big districts and eleven soil-forming sedimentary evironment subranges by analyzing geological background, soil, landform, hydrology and other factors synthetically. Comparative analyses of contents of Se in surface and deep soil of each subrange show that the content of Se in Hebei Plain is low and uneven distribution, and exists Se enrichment zone in Tangshan,Banding, Shijiazhuang -Handan.The research delimits the Se anomalous scope and the anomalous lower limit of this local through contrastive analyses between deep and shallow layer soil and data processing utilizing X±nS(n=1.5～3). According to the content difference between deep and shallow layer soil, Se geochemical background, transect analysis of anomalous zone and cluster analysis, we carried out the analysis of anomalous cause and the result shows that the anomalous sources in shallow layer soil are relative to man-made factor mainly and estimates the propotion of man-made fator and natural fator is 3:1.Based on the content of Se in rock samples, soil samples, irragating water, atmosphetic dust and fertilizers, the research estimate the anomalous sources and point out the anomalous sources in deep layer soil are not relative to man-made factor but controlled by regional geological background; the content of Se in shallow layer soil is affected by geological background and man-made fator. In addition, the author points out the main man-made factors of Se utilizing flux research in Hebei Plain.Response relation equation is established through studying the corelation between Se in wheat seed and corn seed and in root soil. Based on the response relation equation and multiple target geochemical data, we estimate the content of Se in wheat seed and corn seed and evaluate the safety of crops systematically in research areas. According to grading standards of Se in soil, the research grade the soil in Hebei Plain and determine the area and proportion of each grade, and provide scientific evidence for agricultural structure adjustment of Hebei province.更多还原