磁铁矿区河流沉积剖面中磁化率与重金属含量相关性分析

Correlation Analysis on Magnetic Susceptibility and Heavy Metal Content in Fluvial Sedimentary Profile around Magnetite Mine

选择广东省铁帽顶铁矿区下游一河流沉积剖面为研究对象,测定沉积物的磁化率与元素含量并作相关性分析,以考察磁铁矿床周边沉积物磁化率指标对重金属富集程度的指示作用。结果显示,该剖面中低频质量磁化率χlf为0. 87×10-6m^3/kg～184. 93×10-6m^3/kg,频率磁化率χfd为0. 5%～7%。χlf仅与Fe2O3呈现极显著的正相关关系,与其他重金属元素相关性差;χfd与Mn、Pb、Cd及REE均呈正相关;元素Cu、Zn、As等与χlf、χfd的相关性都很差。表明在该种磁化率和重金属元素含量背景值均高的特殊地区,简单地利用磁化率指标指示重金属污染水平需谨慎。

A dowmstream sedimentary profile in Guangdong Tiemaoding mining area was selected as the research objective, the correlation between magnetic susceptibility and heavy metal content in the sediment was studied on magnetic susceptibility indicating the enrichment of heavy metal in the surroundings of the magnetite deposit. The results showed that the low frequency magnetic susceptibility (χ lf ) ranged from 0.87×10^-6 m^3 /kg to 184.93×10^-6 m^3 /kg, and the frequency magnetic susceptibility (χfd ) ranged from 0.5% to 7%.χ lf had only a significant positive correlation with Fe2O3 , and was poorly correlated with other heavy metals. Mn, Pb, Cd and REE had significant positive correlations with χfd . Cu, Zn and As had poor correlation with χlf or χfd . Caution is needed when simply using magnetic susceptibility index indicating heavy metal pollution in the special area with high background of magnetic susceptibility and heavy metal content.