天山黄土粒度特征及粉尘来源

Characteristics of Loess Grain Size and Source of Dust in Tian Shan,China

天山北坡和伊犁盆地晚更新世典型黄土剖面粒度分析表明,天山黄土以粉砂为主,占60-70%左右,粘粒含量一般在15-20%之间。天山北坡黄土物质主要来源于其北部的准噶尔盆地中的沙漠,伊犁盆地黄土粉尘则来自中亚荒漠和伊犁河下游沙漠地区。形成黄土的粉尘主要是以尘暴方式搬运,且冰期和间冰期都有尘暴堆积。

The analysis of grain size of later Pleistocene loess covering on the northern slop of Tian Shan Mountains and Ili Basin shows that the Tian Shan Loess is composed mainly of silt, accounting for 60 - 70%, and some clay, accounting for 15 -20%. The loess covering on the northern slop of Tian Shan Mountains derives from the desert in Junggar Basin but the loess depositing in Ili Basin may come from the desert of Central Aisa and the lower reach of Ili River. The substances making up of loess on the northern slop of Tian Shan Mountains and Ili Basin are carried by dust storm not only in glacial but in interglacial.