Element geochemical characteristics of the reticulate red clay in southern China and its significance for the formation proccess of reticulated mottles

Reticulate red clay in southern China is a kind of special stratum that formed in a monsoonclimate condition,which is of great significance to reconstruct the Quaternary climate environment. For a long time,there is a lack of adequate understanding of physical and chemical characteristics of the formation process of reticulated mottles. Three sections of reticulate red clay,which were located in the Jiujiang and Pengze of Jiangxi Province,and Yueyang of Hunan Province,were studied,and the red matrix and the white reticulated mottles were separated and the geochemical elements,free iron content and so on were analysed. The results show that:( 1) In the white reticulated mottles,Fe,Mn,Th,Ga,Cu,Zn,Co,Ni,Cr,V elements are outstanding leaching,while Zr,SiO_2,Hf and light rare earth elements are obvious enriched,and the content of free iron are low; in the red matrix,they are reversed.( 2) Fe~(2+)content is higher in the white reticulate,while lower in the matrix,which indicates white reticulate tend to be develope