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通过对黄河中游地区马兰黄土的大面积野外实地考察、系统采样和室内化学分析,并采用质量加权平均的计算方法,给出了较为准确的马兰黄土主要化学成分的平均数据。马兰黄土与世界各地的黄土相比,它们的主要化学成分之间存在明显差异,这意味着世界各地的黄土在物源区的物质组成、地质地理条件及古气候等方面可能存在一定差别。马兰黄土相对于全球下地壳和全地壳较富Si,K等亲石元素而贫Fe,Mg,Ti,Mn等亲铁元素;与全球上部大陆地壳相比,马兰黄土除相对较富Ca而贫Na外,其余大多数元素如Si,Al,Fe,Mg,Ti和Mn等的平均丰度极其相似,表明马兰黄土确实是上部大陆地壳广大范围内各类型岩石风化碎屑(粉尘)的混合物。
Through the field investigation, systematic sampling and indoor chemical analysis of large area of Malan loess in the middle reaches of the Yellow River, and using the method of mass weighted average, the average data of the main chemical components of Malan loess is obtained. There is a clear difference between the main chemical compositions of Malan loess and loess around the world, which means there may be some differences between loess areas around the world in terms of material composition, geo-physical conditions and paleoclimate in the provenance area. Malan loess is depleted of Fe, Mg, Ti, Mn and other pro-iron elements relative to the lower crust and the whole earth crust in the world and is rich in Si, K and other lithophile elements. Compared with the upper continental crust in the world, Malan loess is relatively poor and rich in Ca Na, the average abundance of most other elements such as Si, Al, Fe, Mg, Ti and Mn are very similar, which indicates that Malan loess is indeed a mixture of various types of rock weathering debris (dust) within the upper continental crust.