Abstract: Lithological characteristics, sedimentary structure, mass-specific magnetic susceptibility and frequency-dependent magnetic susceptibility studies and correlation to the δ¹⁸O curve of DSDP607 & V30-97 show that loess began to deposit on the terrace of the Yellow River about 1.20 Ma B P, and passed thirteen climatic changes from drier and cooler to warmer and wetter later. The turn of sedimentation from alluvium to loess, an event of transformation from accumulation to down-cut of the Yellow River, indicates a sharp tectonic uplift occurred around 1.2 Ma B P.

Key words: loess-paleosol, susceptibility, climatic changes, tectonic movement, Yellow River, Yangfan section

摘要： 通过对杨范剖面黄土地层岩性特征、沉积结构、质量磁化率和频率磁化率的分析及与深海氧同位素曲线的对比，划分了剖面地层，初步确定了黄土沉积始于1.20 Ma B P,黄土沉积以来该区发生了13次大的干冷-暖湿气候变化；沉积转型指示河流强烈加积转变为河流侵蚀，代表约在1.20 Ma B P发生过一次强烈的构造抬升事件。

关键词: 黄土-古土壤, 磁化率, 气候变化, 构造运动, 黄河, 杨范剖面