毛乌素沙漠西南部,在内蒙古自治区伊克昭盟鄂克托旗布拉格公社至城川公社一带(简称布城区),在长约一百公里范围内,有固定型、半固定型和流动型等各种沙丘,呈西北一东南向断续分布。该区砂样是从西北向东南约以间距10—15公里依次取得(图1),在各取样点分别采有风砂样和下伏第四系土样,共采样17块。风砂样采自沙丘顶部迎风坡(坡角10°—20°)与背风坡(坡角30°)交界附近,深约20公分处。

This article studies the grain size distribution curves of the eolian sands and thechief features of the grain size parameters in southwestern part of the Maowusu Desert.The following conclusions are obtained.1. The eolian sands in this area are chiefly shaped by winds of two contrasting direc-tion, the Northwestern and the Southeastern, of which the former being dominate.2. The chief characteristics of the eolian sands are: sorting is excellent; transpor-tation process is uniform, with saltation dominating; and hence they can be identifiedand differentiated from the fluvial sands.3. The grain size distribution curves might be used for investigating the materialsource of the eolian sands.