Composition and transformation of argillaceous cutans in soils as dependent on the character of gleyification processes and parent rocks

摘要

The paper considers the chemical composition of argillaceous cutans (argillans) in a range of soil types on various Russian parent rocks (glacial, postglacial, and pre-Quaternary). The morphological and chemical composition of the cutans was closelycorrelated with the degree of hydromorphism. Illuvial horizons of dernopodzolic and boggy-podzolic soils are shown to develop under the influence of chemically aggressive mobile fractions of humic substances. Pedogenetic processes are especially pronounced along soil fractures. Cutans carry information on the development of podzolic process and degree of gleyification in the soil profile. The criteria of gleyification are (1) the loss of total iron from the fine material of the cutans, (2) the loss ofnon-silicate iron from the diffusive material (plasma) of the cutans, and (3) the increase in the SiO2:Fe2O3 ratio in the cutans.