关键词: 新生沙丘, 原始沙丘, 粒度, 风沙流, 腾格里沙漠

Abstract: Sand samples are selected from two different kinds of sand dunes, the transverse neonatal sand dune and the transverse untouched sand dune, in southeast margin of the Tengger Desert. The transverse neonatal sand dunes were newly formed on the flat floating sand where sand dunes are bulldozed in a sandstorm observation field. The transverse untouched sand dune is out of the sand storm observation field and never be affected by human. Samples are taken from the near-surface to analyze grain size distribution. The goal of our work is to explore the spatial differences of the composition of particle size on the sediment surface between the two kinds of sand dunes, and between the different parts of the same kind of sand dunes, which reflect the process of the sand movement around the surface. The results have shown that the main sand of the transverse dunes in the southeast edge of the Tengger Desert was thin sand (53.87%),the subsequent part is medium sand (42.57%), but the coarse sand and the more subtle sand are all scarce. The average diameter of the neonatal sand dune was bigger than the untouched sand dune, and both of the two types of sand dunes have good separation characteristic. The gradient of them is characterized by symmetrical type, and the kurtosis of them is belong to medium type; Because of the difference of two types of sand dunes in developmental stages and scales, even in the same wind conditions, there are obvious difference about the particle size distribution on the surface and these two kinds of sand dunes at different position.

Key words: neonatal sand dune, untouched sand dune, particle size, sand flow, Tengger Desert