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本文采用游离铁和全铁的比值，建立了0．220MaB．P．以来长武黄土-古土壤序列的高分辨率古风化强度序列，揭示出0．220MaB．P．以来黄土高原古环境发生了一系列千年尺度的变化，且多数在同一剖面的磁化率记录上没有明显反映或反映较弱。由于该地区冬季土壤温度低于0℃，化学风化的强度主要受控于夏季的温度和降水。据此我们认为，这种千年尺度的波动是东亚古夏季风强度变化的信号。此指标与格陵兰GRIP冰芯δ18O记录对比发现，二者在末次冰期有较好的吻合性，而夏季风在末次间冰期（深海氧同位素阶段5e）及以前的变化要平缓得多。因此，本文的结果显示出：0．220MaB．P．以来，东亚夏季风在千年尺度上的大幅度变化在末次冰期最为显著，此前则表现为一种较为稳定的模式。
In this paper, the ratio of free iron and total iron, established 0.220MaB. P. Since the high-resolution paleo-weathering intensity series of loess-paleosol sequences of Changwu County, the intensity of 0.220MaB was revealed. P. A series of millennial scale changes have taken place in the paleoenvironment of the Loess Plateau, and most of them have no obvious or weak reflection on the susceptibility records of the same section. As the winter soil temperature in this area is below 0 ℃, the intensity of chemical weathering is mainly controlled by the temperature and precipitation in summer. Based on this, we believe that the fluctuation of this millennium scale is the signal of the intensity change of the ancient summer monsoon in East Asia. Compared with the δ18O record of the GRIP ice core in Greenland, this indicator shows a good agreement between the two in the last glacial period, whereas the summer monsoon changed much more slowly in the last interglacial (deep-sea oxygen isotope stage 5e) and earlier. Therefore, the results of this article show: 0.220 MaB. P. Since the last glacial period, the significant change in the East Asian summer monsoon over the millennium scale has been most pronounced, after showing a relatively stable pattern.