陇西盆地段黄河发育时代问题的新认识

The latest advance in the problem of the age of The Yellow River development in Longxi Basin

根据陇西盆地的两个次级盆地阶地即兰州盆地最高级黄河阶地和陇西盆地黄河一级支流大夏河最高级阶地的磁性地层学研究表明，二者的形成时代大致相同，约为１．６ＭａＢ．Ｐ．左右，也即此时黄河才开始在这两个盆地中出现．这一结果修订了黄河在陇西盆地中出现的最早时间．完整的黄河阶地系列实际上是第四纪期间青藏高原阶段性隆升的忠实记录．

Lanzhou and Linxia Basins are two sub-basins of Longxi Basin. The latest geomagnetic studies on thehighest terrace (T_7 ) of the Yellow River in Lanzhou Basin and the Daxiahe river a tributary of Yellow River inLinxia Basin show that they have the same history of development, all were formed at about 1. 6MaB. P..That's to say, the Yellow River tri these two basins appearred at that time. This results have revised the earliest age of the appearance of the Yellow River in Longxi Basin. The complete Lanzhou Yellow River terraceseries are in fact the devoted records of the uplift stages of Xizang-Qinhai (Tibet ) plateau during Quaternary.