摘要
研究发现，武威黄土剖面中稀土元素表现出三种类型：贫轻稀土型、富重稀土型和贫重稀土型；稀土元素平均含量变化及稀土分布模式与黄土高原典型剖面可以对比甚至一致，特征参数平均值也十分接近．提出稀土特征参数δＥｕ，δＣｅ和ＬＲＥＥ／ＨＲＥＥ构成的三角图解，可以揭示不同时代、不同源区或同一源区不同物质组成对于黄土物质的相对贡献，进而追索黄土的物质来源．黄土是一类高度均一化的广源沉积物；腾格里沙漠对于黄土而言在全球气候恶化、变干、变冷、区域地质构造稳定或相对隆升及沙漠发展时期是一物源区．
REE study results on Wuwei Loess section, which is located at north slope of Qilian Mountains and south vicinity of Tengger Desert shown that three types of the REE contents can be distinguished. They are the types of being poor in LREE, rich in HREE and poor in HREE. These phenomena resulted from the input of the near source materials, the various loess accumulation periods and the changeable local environment. On the other hand, the similarities of the average REE contents and the REE distribution patterns between loess sections from the Loess Plateau can be regarded as evidence to show that the loess shares a common general source material supplying area. That area is the dry central Asia, including northwest Tengger Desert. At the same time, it has been found that the triangular digiam figure made up by the REE characteristic indices, LREE/HREE,δEu and δCe can be used to display the variations of the samples with different times and from different sections, so it can be used to trace the source areas for loess deposits. It can be concluded that Chinese loess is one kind of completely unificated deposits which are transported from different areas. Tengger Desert is not only one of source areas where the global climate deterioration results, but also a deposition basin during the warm humid period.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
1998年第4期157-164,共8页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金
