金华高村红土剖面的粒度与磁化率特征研究

Characteristics of Grain Size and Magnetic Susceptibility of Red Clay Profile in Gaocun

对浙江省金华市高村(GC)红土剖面的粒度组成、剖面磁化率特征及总碳(TOC)含量变化进行了研究,探讨其对第四纪红土形成环境的指示意义。结果表明,GC红土剖面粒度组成的频率曲线主要呈现多峰特征,表明了其形成环境的复杂性;GC红土剖面结构与AB型相似,呈二元结构,上部与下蜀黄土、加积型红土形成相似,系风成成因,下部具明显的冲积相特征,应为河流冲积形成;从磁化率曲线也可反映其形成环境经历了数次的冷暖交替;土壤样品中TOC值总体不高,从地表向下,其值大致呈波动下降趋势。

The paper studied the size composition, magnetic susceptibility characteristic of red clay cutaway and the changes of TOC content, and explored its implications for red clay in Quaternary period to forming environment. The results indicated that the grain size frequency curve mainly present multimodal features, which means the complexity of the forming environment. The GC profile is similar to AB profile, both presents dual structure. The formation reason of upper is eolian deposit, the same with that of Xiashu Loess and aggraded red earth. The lower apparent obvious alluvial traits, so its soil should be made of river alluvions. According to the magnetisability curve, it can be concluded that the environment got through changes in temperature at many times. TOC value of soil sample was not high in total,down from the surface, there roughly was a downtrend of fluctuation.