粒度揭示的末次间冰期以来长江中游风沙-风尘体系  

Sand-loess System in the Middle Reaches of Yangtze River since Late Interglacial Indicated by Grain Size

作　　者：胡亚萍[1] 贾玉连[1,2] 张智[1] 彭学敏[1] 凌光久[1] 王朋岭[3] 

机构地区：[1]江西师范大学地理与环境学院,江西南昌330022 [2]江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,江西南昌330022 [3]国家气候中心中国气象局气候研究开放实验室,北京100081

出　　处：《中国沙漠》2013年第5期1324-1332,共9页Journal of Desert Research

基　　金：国家自然科学基金项目(41262007);江西省研究生创新基金项目(YC2012-S050);江西师范大学研究生创新基金项目(YJS2012016)资助

摘　　要：对长江中游地区定山-太平断面上砂山砂与下风向5个黄土剖面黄土进行了详细的粒度分析,并与其他地区黄土进行对比。结果表明:(1)粒度象和粒度参数特点显示赣北定山-太平断面砂山下风向的黄土状土为风积成土;(2)定山-太平断面的砂山砂-砂山淤泥-黄土粒度特征的渐变过渡,指示了其沉积上的渐变过渡关系。结合区域各沉积相的年代序列认为,末次间冰期以来,长江河谷、漫滩等松散碎屑物在冬季风分选下,粗颗粒物质以砂山形式在其下风向不远处沉积,而剥离出的细颗粒物质则被颠扬到较远的下风向以黄土的形式堆积,从而在区域上形成一个以砂山砂和黄土为主的风沙-风尘沉积体系。Based on the grain size analysis on the sand and loess at 5 profiles of the Dingshang-Taiping sec- tion in the middle reaches of the Yangtze River, we discussed the connection of sandy hill and loess in this region. The results are as follows： （1） The loess in Dingshang-Taiping section is obviously different from those of fluvial sediments but is the same as the aeolian sediments in other region, so it is aeolian origin. （2） The gradual transition of deposit is indicated by the gradual transition of the grain size of sand, mud and lo- ess in the section. Combined with the timing sequence data of the sediments in this region, we conclude that the fluvial sediments in the the Yangtze River were eroded by the strong winter monsoon and the coarse par- ticle was deposited at leeward in form of sandy hill since the last interglacial. The fine particle from flood plain of the Yangtze River were transported far away and deposited in form of loess. The sand in sandy hill and loess in leeward of sandy hill is just a sort of synchronous deposit accumulated in our study region. The sandy hill sand and loess deposit makes up the regional sand-loess system in north Jiangxi province, China.

关 键 词：风沙-风尘沉积体系 粒度特征 末次冰期 

分 类 号：P53[天文地球—古生物学与地层学]