沿84°E线附近横穿塔克拉玛干沙漠,采集了沙丘、丘间地、冲积及洪积沙样品进行粒度分析,着重研究风成沙的粒度特征。结果表明沙丘沙以极细沙为主,0.1—0.05mm含量占60—80％。粉沙(<0.05mm)含量0—5％。无粘粒组分。平均粒径区间3.15—3.6ф,总体平均3.53ф(0.087mm)。分选好(δ_I值0.27—0.39,平均0.35)。负偏为主(SK值—0.67—0.47,平均-0.15)。单众数为主,众数粒径4.0ф,少数样品为双众数。累积概率曲线主为三段或二段式。地面滚动组含量<5％,斜率<63°;跃移组分含量90％左右,斜率60—85°,二者截点2.64ф。少数含悬移组分的样品中,悬移与跃移组分截点4.32ф,含量<5％。作为对照,文中对丘间地、冲积、洪积物的粒度参数及粒度分布曲线特征也进行了讨论。

Sands are mainly from the dunes, interdunes, and alluvial and pluvial sediments in the vicinity of the longitude 84癊. The samples in Taklamakan desert, which has simple barchan dunes, longitudinal dunes, asnd drifts, compound barchan dunes and complex transvers bar-chanoid dunes and longitudinal ridges, were collected from sites with areas of approximately 20 X 20 cm and to a depth of 5-lOcm. 100 grams of the material were sieved. The material which is finer than O.lmm was analyzed using the sedimentation method.