Iron Oxides n Burozems on Red-Colored Deposits in european Russian and the Color Differentiation of Soils

摘要

The composition,content,and color-forming role of iron and manganese(hydr)oxide minerals in the profiles of weakly differentiated soils on Permian red-colored deposits in the northern and southern taiga red-borwn loamy sands,and calcareous raw-humus burozem on carobnate aleurites)were studied.It was found that the differences in th color of genetic horizons of finely textured calcareous and clay-illuvial burozems on red-colored deposits are determined by the content of hematite,the main iron-bearing pigment.The portion of hematite calculated form the spectral characteristics of soils averages 68 and 79% of totail iron (hydr)oxides in calcareous and clay-illuvial burozems,respectively.The color of coarse-textured podzolized burozem does not depent on the content of hematite.The active development of iron oxidogenesis occurs presently in podzplized raw-humus burozem.It is manifested in the formation of ferrihydrite 2Fe_2O_3 centre dot FeOOH centre dot 4H_2O and feroxyhite delta-FeOOH in the upper part of the profile.