【摘要】 调查了准噶尔盆地玛纳斯湖、阿拉善高原居延泽及民勤盆地猪野泽等北方众多的现代干枯湖泊 ,重点分析了干枯湖床沉积物粒度组成。干枯的玛纳斯湖、古居延泽以及民勤盆地古猪野泽沉积物粒度分析结果表明 ,干枯湖床的地表湖相沉积物粒径小于 10 μm的颗粒占 6 0 %以上 ,干涸湖床上沙质草原地表也含有大量小于 10 μm的粘土颗粒 ,含量接近 5 0 % ;而弃荒土地地表细颗粒物质散失迅速 ,民勤盆地弃荒土地地表粘土含量仅存不到 13.9%。中国西北地区活动沙丘粒度组成小于 6 3μm粒径的颗粒很少 ,小于 10 μm的颗粒微乎其微。因此西北沙漠地区活动沙丘沙对华北或华东地区影响相对较小。认为沙尘暴、扬沙或浮尘天气虽然多发生于中国西部沙漠、阿拉善高原沙区、河西走廊北部沙区以及蒙古东部、中部地区 ,但由于粗颗粒沙扬起高度与搬运距离有限 ,真正影响整个华北、华东地区的沙尘物质是小于 6 3μm的粉砂级别的颗粒 ,特别是小于 10 μm的粉尘。认为影响东亚地区的粉尘天气物源不仅是中国西部的内陆沙漠、沙地 ,更重要的是干枯的湖泊、弃耕的荒地与裸露的沙砾草场。更多还原

【Abstract】 Some dry lakes widely distributed in the north of China has been investigated in this paper based on analysis of grain-size distribution of the sediments of these dry lakes, including Manas Lake in Junggar Basin, Juyan Lake in the Alxa Plateau, Yezhu Lake in Minqin Basin and so on. The analyzed results are as followed: the total volume-percentage of the particles (<10 μm) of dry lake-bed surface sediments is above 60%. There are plenty of clay particles (<10 μm) on the surface of sandy grassland developed from dry lake-bed and the content amount to about 50%. The tiny particles on the surface of abandoned land can be blown away easily and rapidly, so the content of clay particles in Minqin Basin is less than 13.9%. The grain-size distribution of active dune in northwest of China is the fewness of particles (<63 μm) and very little of the particles(<10 μm). Frequently, sands of active dune in northwest desert areas have weak influence on North China and East China. It is considered that although the weather of sand-dust storm, blowing-sand and suspending-dust occur originally in the western desert, sandy areas of the Alxa Plateau, the north of Hexi Corridor and the east, center of Mongolia, it is the sand-dust materials(<63μm),especially those dust(<10μm) really influence North China and East China for limitation of transportation distance and height of coarse particles. It is concluded that material sources that influence the sand-dust weather of East Asia are not only inland deserts, more importantly, but also the dry lake, abandoned land and bare sand-gravel grassland.更多还原