同位素在风成沉积物物源判别中的运用

The Application of Isotopic Composition in Aeolian Sediments Provenance Discriminance

同位素示踪方法在风成沉积物物源研究领域应用较广泛,由于风成物质在风化、传输和沉降过程中其同位素地化特性不会发生变化,因此通过物源区和沉积区风成沉积物同位素组成的对比,相似同位素组成的地区可确定为物源区。同位素物源示踪的主要方法有石英颗粒的δ18O、硅酸盐部分的Sr-Nd组成、沉积物的Hf和Pb组成特征等。这些方法在中国西部盆地(如塔里木盆地)沙漠砂来源、黄土高原黄土物源(如柴达木盆地对黄土高原的物源贡献)等领域得到了广泛应用,取得了众多成果。

As an effective detecter of provenance in the provenance-researching realm of aeolian sediments, the isotopic tracer technique is applied extensively. And the principle of which is： because of the geochemical characteristic of aeolian sediments will not change in the course of weathering, transportation and precipitation, so by the comparison, if they bear the similarity on the isotopic compositions between the provenance area and trap area, we can generally ascertain the origin of the aeolian sediments. The iso- topic tracer technique mainly includes the 8~SO of quartz grains, Sr-Nd isotopic composition of silicate fraction and other isotopes such as Hf and Pb. The above technique was used widely on the phases which were to trace the origin of sand in Chinese western basins （such as the Tarim Basin） ,to certain the prove- nance of Chinese Loess Plateau （ e. g. the provenance contribution of Qaidam Basin to the loess plateau）, and it got tremendous progress on the above researching realm in recent years.