额济纳盆地戈壁纵剖面沉积物粒度参数分析  

Particle Size Characteristics of Sediment Profile in Gobi of Ejina Basin

作　　者：王丽琴[1] 李红丽[1] 董智[1] 沈运扩[1] 张志鹏[1] 杨文斌[2] 

机构地区：[1]山东农业大学林学院山东省土壤侵蚀与生态修复重点实验室泰山森林生态站,山东泰安271018 [2]中国林业科学研究院荒漠化研究所,北京100091

出　　处：《水土保持研究》2014年第1期152-156,162,共6页Research of Soil and Water Conservation

基　　金：中国林业科学研究院专项资金重大项目"中国黑戈壁区生态本底调查"(CAFYBB2011002);林业行业专项"中国沙漠分类与编目指标体系研究"(201004059)

摘　　要：以额济纳荒漠戈壁为研究对象,通过野外实地调查与室内实验相结合的方法,采用平均粒径、分选系数、偏度、峰度等粒度参数对戈壁纵剖面沉积物粒度特征进行了分析。研究表明:在纵剖面,除冲积扇上部外,其余采样点均沿垂直方向从上至下沉积物粒度组成由石块变为砂粒;除冲积扇上部外,颗粒平均粒径沿垂直方向呈细化趋势,平均粒径由粗变细;戈壁不同剖面层沉积物颗粒分选系数整体呈分选差或较差,仅东居延海岸边浅滩和东居延海湖岸分选较好或中等;偏度除冲积扇上部呈负偏、极负偏外,其他各点偏度沿垂直方向由上至下趋于近对称、正偏分布;在冲积扇上部和中部,峰态以宽平为主,在冲积扇下部到东居沿海湖岸沉积物沿垂直方向由下至上峰态由宽平、很宽平变成尖窄分布。总之,戈壁纵剖面沉积物的粒度特征整体呈平均粒径由粗变细,分选差或较差,偏度呈近对称、正偏分布,峰态宽平的特点,反映了不同层次颗粒的沉积环境、地貌特征、侵蚀与堆积方式,可为戈壁类型划分提供依据。By taking the Ejina Basin region as the research site, the particle size composition of sediment pro- file in gobi, average particle size, sorting coefficient, skewness and kurtosis were analyzed by field investiga- tion and laboratory test. The results show that each sample point along the vertical direction from top to bot- tom sediment particle size composition from stone into sand on the longitudinal sediment. Except for the top of alluvial fan, the average grain size changed smaller and had significantly thinner trend by vertical direc- tion. The grain sorting coefficient in different profile layers was poor or poorer, but only it was better or me- dium on near shore lake shallow and lake side. Except for the top of alluvial fan, the skewness was from neg- ative to very negative, in other points; the skewness of sediment particle from top to bottom tends to nearly symmetry and positive distribution by the vertical direction. The kurtosis in the top of alluvial fan and in the middle of alluvial fan sediment were flat, while from the alluvial fan edge to lake side sediment by flat, wide flat into sharp distribution from the bottom up. All in all, the sediment profiles of gobi appeares the charac- teristics of fine average grain size, poor or pooer sorting coefficient, nearly symmetry and positive skewness and flat kurtosis, which reflects the particles in different levels of sedimentary environment, geomorphic fea- ture, erosion and deposition pattern, and can provide the basis for the gobi classification.

关 键 词：戈壁 沉积物 纵剖面 粒度组成 粒度特征 额济纳盆地 

分 类 号：P588.21[天文地球—岩石学] X141[天文地球—地质学]