摘要
对撒哈拉沙漠东北部苏丹境内东西方向３６个样品粒度分析结果表明：其粒度组成可分为１０种不同的类型；粒度参数具以下特征值：ＭＺ＝１．３４～２．４３；标准偏差δＩ＝０．５１～１．４３；偏度ＳＫＩ有正有负，变化于－０．３～０．４７；峰态ＫＧ＝０．６６～１．０４。同时显示，绝大多数样品的频率曲线为多峰态，具有典型河流沙的粒度特征；不同样品及粒度分布形式在地域上无明显规律性。分析结果说明非洲撒哈拉沙漠东北部沙漠砂的形成与河流作用有关。
The sand sample grain size measurements show that the 36 desert sand samples takenfrom northeastern Sahara Desert,Sudan,in Africa can be divided into 10 different types;the grain size indies are in the range asfollows:median diameter M Z=1.34～2.43,thestand arddeviation δ I=0.51～1.43;skewnessSK I may be either positive or negetive,butranges from-0.30～0.47,K G=0.66～1.04,mostof the grain size frequence curves of the samples have the characteristics of multipeaks or double peaks,which is the typical structure o friver sand;On the other hand,there is noregular regional grain size distribution patterns in the investigation area.The analytical results reveal that the sand grain of northeastern Sahara was formed under the river lacustrine deposition environment during warm humid climatic condition and had been reformed by wind action later.
出处
《中国沙漠》
CSCD
北大核心
1996年第3期241-245,共5页
Journal of Desert Research
基金
国家自然科学基金
甘肃省自然科学基金
关键词
撒哈拉沙漠
粒度分析
成因
环境
沙漠
Sahara Desert Grain size analysis Formation environment
