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	巴丹吉林沙漠典型高大沙山迎风坡粒度特征
其他题名	Grain size distribution of the aeolian sediments on the stoss slope of a typical mega-dune in the Badain Jaran Desert
	李恩菊 1; 董治宝1 ; 赵景波 2
来源期刊	干旱区地理
ISSN	1000-6060
出版年	2011
卷号	34 期号:3 页码:471-478
中文摘要	风沙地貌形态与地表风动力的互馈机制研究是近年来风沙地貌学研究的热点问题。以巴丹吉林沙漠高大沙山为研究对象，选取巴丹吉林沙漠东南部苏木巴润吉林以西高度约400 m的高大沙山，对其迎风坡沉积物粒度特征进行系统采样分析，研究了高大沙山迎风坡沙物质粒度由坡脚至丘顶以及表层和下层的变化规律。结果表明，沙山迎风坡表层沉积物的粒度组分较下层粗。表层沉积物的中、细沙含量相差不大，分别为48．25％和47．91％，而下层沉积物的细沙含量 (58．05％)明显高于中沙(40．14％)。两层沉积物的粗沙、极细沙和粗粉沙含量均很少，且不含极粗沙和粘粒。上下层的粒度组分差异主要是由于表层风蚀和细粒向下分选所致。随着沙山高度和坡度逐渐增加，沙面发生风蚀，沙山迎风坡沉积物粒径总体上由坡脚至丘顶变细，分选变好，偏度趋于负偏，峰态没有明显的变化趋势。但由于局部地形和气流的影响，在高大沙山迎风坡中部偏上，出现粒径变粗，分选变差的异常现象。这一结论表明巴丹吉林沙漠的复合型高大沙山相比简单沙丘经历更为复杂的风沙动力过程，其风沙沉积物的粒度分析更为复杂。因此，必须综合考虑多种因素来探讨其风沙动力学机制。
英文摘要	Grain size distribution of aeolian sediments which bear rich information about the dynamics of dunes is an important aspect in sand dune geomorphology.The Badain Jaran Desert of China has the tallest mega-dunes in the world,whose formation dynamics is an open question.A 400 m tall mega-dune located in west of the Southern Badain Lake in the southeast Badain Jaran Desert was selected to study the grain size distribution of the aeolian sediments on the stoss slope.42 sediment samples were collected at 21 sites on the stoss slope with an elevation interval about 20 m.They were analyzed by a Malvern Mastersize 2000 laser particle size analyzer in laboratory.The variation with height of mega-dunes in grain size distribution was discussed and the difference between surface sediments and sub-surface (below 50 mm)sediments was compared.It is indicated that the fractions of medium and fine sands does not differ significantly in the surface sediments,being 48.25% and 47.91% respectively.However,the sub-surface sediments contains significantly more fraction of fine sand than medium sand,being 58.05% and 40.14% respectively.Little coarse,very fine sand,silt and clay is contained in both surface and sub-surface sediments.It is suggested that wind sorting and downward movement of fine sand are repsobible for the difference in size distribution between surface and sub-surface sediments.Finer particles are easier to be blown away by wind and move downward between coarser particles.With an increase in mega-dune height,sediments generally tend to become finer,better sorted and negatively skewed,but Kurtosis does not show apparent change trend.This implies that sedimets are moved by wind from the foot to the top of the stoss slope and current wind action is ative in shaping the mega-dunes in the Badain Jaran Desert.However,local relief and airlflow can cause irregular variation in grain size distribution.This explains coarser and poorer-sorted sediments occur at a few sites located on the upper stoss slope.The relaionships between grain distribution parameters are very scattered and do not show regular change with mega-dune height; It is suggested that mega-dunes in the Badain Jaran Desert,which are compound types have been experiencing more complex processes than simple dunes although wind is the dominant factor.Consequently,the relationship between grain size distribution of sediments and dune dynamics is more complex.The gain size properties must be combined with other factors to explain the dynamics of mega-dunes.
中文关键词	风沙地貌 ; 高大沙山 ; 粒度组成 ; 粒度参数 ; 巴丹吉林沙漠
英文关键词	Aeolian geomorphology mega-dunes grain size composition grain size parameters Badain Jaran Desert
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOSCIENCES MULTIDISCIPLINARY
WOS研究方向	Geology
CSCD记录号	CSCD:4219576
来源机构	陕西师范大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/226459
作者单位	1.陕西师范大学旅游与环境学院, 西安, 陕西 710062, 中国; 2.陕西师范大学旅游与环境学院, 黄土与第四纪地质国家重点实验室, 西安, 陕西 710075, 中国
推荐引用方式 GB/T 7714	李恩菊,董治宝,赵景波. 巴丹吉林沙漠典型高大沙山迎风坡粒度特征[J]. 陕西师范大学,2011,34(3):471-478.
APA	李恩菊,董治宝,&赵景波.(2011).巴丹吉林沙漠典型高大沙山迎风坡粒度特征.干旱区地理,34(3),471-478.
MLA	李恩菊,et al."巴丹吉林沙漠典型高大沙山迎风坡粒度特征".干旱区地理 34.3(2011):471-478.