珠三角平原区第四系剖面重金属分布特征及其影响因素

发布时间：2018-05-22 12:21

本文选题：珠江三角洲 + 第四系　；参考：《地球科学进展》2017年08期

【摘要】：选取珠江三角洲冲积平原区4个不同沉积相带的第四系岩心做元素全量分析,并对4种重金属进行了赋存形态分数分析,揭示了珠江三角洲第四系元素地球化学特征主要受物源和沉积环境的控制。不同沉积环境下物源的影响程度不同,物源在三角洲平原相的沉积环境下影响强度最大,在海陆交互强烈的沉积环境下,物源的影响减弱,海陆交互作用的影响增强。不同重金属元素由于自身化学性质的差异,其对沉积环境的敏感程度有所不同。研究区Cd富集显著,且其活性态比例最高、潜在生态风险最大;而As,Hg和Pb的富集程度较弱,且As和Hg主要以残渣态的形式存在,Pb主要以残渣态和铁锰氧化物态为主,它们的生态风险相对较低。不同的沉积环境下p H等理化指标对Cd形态的影响不同,Cd的活动态主要与p H和淋滤系数有关。
[Abstract]:The Quaternary cores of four different sedimentary facies zones in the alluvial plain area of the Pearl River Delta are selected for the total element analysis, and the occurrence fractions of four heavy metals are analyzed. It is revealed that the geochemical characteristics of Quaternary elements in the Pearl River Delta are mainly controlled by the provenance and sedimentary environment. The influence degree of provenance is different in different sedimentary environments. The influence of provenance is the greatest in the sedimentary environment of delta plain facies. In the sedimentary environment with strong interaction between sea and land, the influence of provenance is weakened and the influence of interaction between sea and land is enhanced. The sensitivity of heavy metal elements to sedimentary environment is different due to their own chemical properties. CD enrichment was significant in the study area, and its active state ratio was the highest, and the potential ecological risk was the biggest, while the enrichment degree of Ash Hg and Pb was relatively weak, and as and Hg mainly existed in the form of residuals, such as residual form and ferromanganese oxide state. Their ecological risks are relatively low. The effects of pH and other physical and chemical indexes on CD forms in different sedimentary environments were mainly related to pH and leaching coefficient.
【作者单位】：中国地质大学(北京)地球科学与资源学院;中国地质调查局南京地质调查中心;广东省地质调查院;中国地质科学院地球物理地球化学勘查研究所;
【基金】：中国地质调查局地质大调查项目“珠江三角洲土壤重金属地球化学成因与风险评价”(编号:12120115050401) 痕迹科学与技术公安部重点实验室开放课题(编号:2015FMKFKT03)资助~~
【分类号】：X142

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