临汾盆地褐土剖面磁化率与粒度垂直变化特征及相关性研究

Study on Vertical Variation Characteristics of Magnetic Susceptibility and Grain Grade of Brown Soil Profile in Linfen Basin and Their Correlation

[目的]研究临汾盆地褐土剖面磁化率与粒度垂直变化特征及相关性。[方法]在临汾市尧都区农田取120 cm深的土壤剖面,每5 cm连续采样,对所取的24个土样进行磁化率和粒度的分析。[结果]磁化率随土壤深度增加而递减,>50μm粒级含量随着土壤深度的增加而递减,10～50、1～10、<1μm粒级含量随着土壤深度的增加而递增。地表以下0～30 cm为砂土,30～120 cm为粉土。磁化率与1～10、<1μm粒级含量均呈极显著负相关,与>50μm粒级含量呈极显著正相关,与10～50μm粒级含量不相关。频率依赖系数XFD1.0与>50μm粒级含量呈负相关,与10～50、1～10、<1μm的粒级含量呈正相关;XFD0.1与10～50μm粒级含量呈极显著负相关,与>50μm粒级含量呈显著负相关。[结论]磁性颗粒主要赋存于粗颗粒物质中;磁化率及粒度对沉积环境和古气候的变化有一定的响应。

[Objective]The aim was to study vertical variation characteristics of magnetic susceptibility and grain grade of brown soil profile in Linfen Basin and their correlation.[Method]Soil profile with the depth of 120 cm from Yaodu farmland of Linfen was sampled,then,successive sampling was carried out for each 5 cm,finally,the analysis on magnetic susceptibility and grain grade of 24 obtained soil samples were carried out.[Result]Magnetic susceptibility negatively correlated with the increase of soil depth,the content of 50 μm grain size negatively correlated with the increase of soil depth,the content of 10-50,1-10 and 1 μm grain size positively correlated with the increase of soil depth.The soil texture under the surface 0-30 cm was sandy soil,under the surface 30-120 cm was floury soil.Magnetic susceptibility and the content of 50 μm grain size were extremely significant positive correlation,and had a significant negative correlation with the content of 1-10 and 1 μm grain size.Magnetic susceptibility and the content of 10-50 μm grain size were relevant.Frequency dependent susceptibility XFD 1.0 and the content of 50 μm grain size were negative correlation,and had a positive correlation with the content of 10-50,1-10 and 1 μm grain size.Frequency dependent susceptibility XFD 0.1 was extremely significant negative correlation with the content of 10-50 μm grain size and significant negative correlation with the content of 50 μm grain size.[Conclusion]Magnetic particles were mainly occurred in coarse-grained materials;magnetic susceptibility and grain size had certain response to the variation of depositional environment and paleoclimate.