准噶尔盆地沙物质粒度特征研究

Study on the Grain Size's Characteristics of the Sand Materials in the Jungger Basin

准噶尔盆地系统采集样品的机械组成分析揭示了该盆地中多种自然因素作用下的沙物质粒度分布状况。该盆地沙漠沙物质组成主要为细沙和中沙 ,比塔里木盆地的要粗。对比盆地内部沙物质粒级发现 ,中部最粗 ,北部中等 ,南部偏细。分析结果表明 ,盆地沙物质粒度总体特征首先受物源这一大背景制约 ,其次在区域构造、沙漠地貌、植被气候条件影响下 ,不同小区和不同产状的沙物质间粒度特征存有差异。

The analysis of the mechanical composition on the sand materials, sampling from the Jungger Basin in systematic way, reveals the grain size's distribution of the sand materials in the basin under many kinds of natural factor actions. The composition of the sand materials from the desert areas in the basin mainly consists of fine sand and middle sand, which is coarser than that in the Taklimagan Desert. Comparing the arithmetic mean diameters of the sand materials in the basin, it is seen that sand of the middle part of the basin is coarser, the north part medium and the south finer. The results of the analysis show, generally, the grain size's characteristics of the sand materials in the basin are first restricted by the material sources. Secondly, under the effects of regional tectonics, sandy desert landform, vegetation cover and climatic condition, there are the differences of the grain size's characteristics between the sand materials from different small areas and types.