中文摘要：

本文以江苏省南京市雨花台红土作为研究对象，进行野外形态观察及室内磁化率、游离氧化铁和颗粒组成的测定，结果表明，土壤剖面按形态可自上而下依次划分为黄棕色土层、红棕色土层和网纹红土层3大层段；低频磁化率呈黄棕色土层〉红棕色土层〉网纹红土层的特点，网纹红土层和红棕色土层的游离氧化铁和游离度均高于上部黄棕色土层，指示红色土层有更强的风化成土作用；网纹红土层〈10μm细颗粒和〉100μm颗粒的增加，进一步表明其经历了更强烈的风化成土作用。因此，雨花台红土剖面自下而上低频磁化率逐渐升高，反映的是气候由湿热向温凉转变的总体特征。

英文摘要：

Soil morphology, magnetism, iron oxides and particle size distribution of the red earth at Yuhuatai, Nanjing was determined and analyzed. Results indicated that： 1） the profile can be divided into yellow brown earth layer, red brown earth layer and reticulate red earth layer; 2） the low frequency susceptibility of soil layers followed the sequence of yellow brown earth layer 〉 red brown earth layer 〉 reticulate red earth layer; 3） free iron oxide （Fed） content and Fed/Fet ratio of the reticulate red earth was higher than that of the yellow brown earth, indicating that the red earth layer experienced a more intensive soil forming process. The higher contents of 〈 10 μm and 〉 100 μm particles in the reticulate red earth also indicated that this layer of soil experienced a more intensive weathering process than the red brown earth. The profile reflected the process of climate change from warm and humid to cooler condition since the Pliocene.