磁性地层研究表明，发生在约78万年前，即第四纪以来最近的一次布容/松山(B/M)地磁场极性倒转事件，在海洋和黄土的记录中存在不同步现象，使得基于地磁极性转换界线年龄的黄土古气候记录与全球的对比存在不确定性。针对这一科学问题，本项目采用宇宙成因核素10Be作为古地磁场变化的示踪计，在黄土高原中部、南部和西部选择3个剖面65-90万年的黄土地层序列为研究对象，对含有B/M极性转换记录的段落开展10Be示踪地磁场变化的研究，在获取高分辨率10Be浓度基础上，应用数理方法提取地磁场强度调制的10Be信号，重建B/M极性转换期间地磁场相对强度变化过程，并与同步研究的高分辨率古地磁结果相比较；将相对地磁场强度、磁学参数与气候代用指标序列相结合，并与海洋记录对比，明确中国黄土中B/M界线的确切位置，转换时间和气候意义，为中国黄土序列提供关键年代标记，服务于亚洲季风-干旱环境变迁与全球环境变化联系的研究。

Magnetostratigraphy studies have revealed that the records of the most recent Brunhes/Matuyama (B/M) polarity reversal event since Quaternary which happened about 780 ka BP from Chinese loess were not synchronous with that in marine sediment. This has resulted in the uncertainties of the climatic correlation between loess and marine sediments on the basis of the age of polarity reversals. Aiming at this problem, we shall choose 3 loess profiles for this project, consisting of 650-900 ka BP sequences at the middle, south and west parts of the Chinese Loess Plateau, using 10Be as a tracing tool to mark the geomagnetic B/M polarity reversal. Based on obtaining the 10Be concentration, we shall try to extract the signal of geomagnetic modulation of the 10Be concentration, reconstruct the relative geomagnetic paleointensity, and finally compare the reconstructed 10Be paleointensity with the paleogeomagnetic results to find the "offset". Combined the 10Be paleointensity with the magnetic parameters and climate proxies in our study, we shall then compare them with marine records, and attempt to determine the exact location of B/M boundary in Chinese loess, reversal process and its climate significance. This can provide an accurate time marker for the Chinese loess sequence and contribute to the study of the Asian monsoon-arid climate variations and its connection to the global change.