马栏河阶地黄土粒度特征指示的粉尘堆积过程

Dust Accumulation Process Indicated by Particle Size End-Member of Malan River Loess

以辽南马栏河阶地黄土为研究对象,运用粒度数据分析了其物源。结果表明:(1)选取无标度区间为概率累积5%~95%数据计算,分维值(2.06~2.32)与洪泛和河床质沉积接近,物源较近;(2)参数化端元分析结果表明:剖面可分解3个端元,EM1是高空西风和西北冬季风搬运内陆的细粉砂沉降组分和少量风化成壤的黏土;EM2是地方风系搬运的冰期出露沿海陆架和马栏河流域裸露河床河漫滩的粗粉砂;EM3是强冬季风或强尘暴搬运剖面附近的极细砂,物质来源复杂。

The terraced loess of Malan River in southern Liaoning Province was studied and its provenance was analyzed with grain size data.①The scale-free interval is selected as the probability cumulative data of 5%-95% for calculation,and the fractal dimension values(2.06~2.32)are close to flooding and river bed sediment,and the source is relatively close;②The results of parametric end element analysis show that the profile can be decomposed into three end elements,and EM1 is the inland fine silt settlement component and a small amount of weathered clay transported by upper westerly wind and northwest winter wind;EM2 is the coarse silt of exposed coastal shelf and exposed riverbed floodplain of Malan River basin transported by local wind system during ice age.EM3 is extremely fine sand near the section transported by strong winter wind or strong dust storm,with complex material sources.