中国北方部分地区黄土、沙漠沙、湖泊、河流细粒沉积物粒度多组分分布特征研究

通过对我国北方部分地区的黄土、沙漠沙、湖泊、河流细粒沉积物的粒度多组分分布特征系统研究后总结了其粒度分布特征及组分间差异，并提出了风成、水成沉积物成因类型的判别依据。认为:1)细粒沉积物粒度一般由多个组分叠加构成，表现为多组分粒度分布特征。2)黄土粉尘粒径以<70 μm的悬浮颗粒为主，粒度由粗、中、细三个组分构成。粗粒组分含量最高，其中值粒径与源区距离呈负相关，中粒组分百分含量与源区距离呈正相关。3)沙漠沙粒度由一个极其明显的粗粒跳跃组分构成，中值粒径一般位于100~300 μm，分选性极好。4)湖泊沉积物粒度分布最多可有6个组分(中值粒径:<1 μm，2~10 μm，10~70 μm，70~150 μm，150~700 μm，>700 μm)，前4个组分属悬浮组分，⑤为跳跃组分，⑥为滚动组分，分选性差。5)河流沉积物粒度分布曲线较复杂，其分布特征蕴含了水动力强弱信息。6)沙漠沙→黄土与河流沙→湖泊沉积物其优势组分的粒径均逐渐变细，但水成相对应组分比风成组分粒径要粗.

The Multimodal Grain-Size Distribution Characteristics of Loess,Desert,Lake and River Sediments in Some Areas of Northern China

By using high-resolution laser grain size instrument Mastersizer 2000,the multimodal characteristics of grain size distribution of loess,desert,lake and river sediments are measured and carefully studied. The standard patterns and their grain size characteristics of various sediments are systemically summarized,the discrepancies of multimodal distribution among these sediments are concluded and the comparisons of grain size multimodal distribution of them are also discussed in this paper. The major conclusi...