黄土高原黄土和太平洋沉积物Nd，Sr同位素变化的比较

A Comparison of Variations in Nd and Sr Isotopic Compositions between the Loess Plateau and the Pacific Sediments

东亚季风环流引起的风尘物质的搬运和堆积，形成了我国的黄土高原。最近几年发表了一些对太平洋沉积物Nd和Sr同位素的研究结果（Asahara，1999；Asahara等，1995；Pettke等，2000）。由于亚洲大陆是太平洋沉积物中风尘物质的主要来源之一，所以将黄土高原研究结果和太平洋沉积物的研究结果相比较，可以得出一些有益的结论。

^143Nd/^144Nd and ^87Sr/^86Sr ratios of acid - washed residues of red clay and overlying loess- paleosols from the Lingtai profile in the loess plateau of China were determined. Sediments in central North Pacific Ocean have different fluctuations of ^87Sr/^86Sr ratios from the Lingtai profile over the last 7.0 Ma. Nevertheless, fluctuations of εNd（0） in the Lingtai Profile from 7.0 Ma B P to the present are very similar to those of central North Pacific Ocean, which reflects the loess of the loess plateau in China and sediments of central North Pacific Ocean are derived from the same source regions, and the source regions have been basically unchanged since 7.0 Ma B P. Red clay and the overlying loess- paleosol have very identical εNd（0）. It can be inferred that both the red clay in the Loess Plateau and the overlying loess- paleoaols are probably of eolian origin and have the same source region. The phenomenon that most of the residues of red clay have higher ^87Sr/^86Sr ratios than the overlying loess- paleosols implies a climate of relatively high temperature and strong rainfall during the formation of red clay.