Dynamics of the system oxisol-gleysol and its relationships with aluminous refractory clay in the Western of Minas Gerais State

Abstract

On the surface of the flat plateaus (chapadas) located in western of Minas Gerais State, the soil landscape is mainly composed by Oxisol-Gleysol. The yellow-reddish Oxisol occurs in well-drained parts of the plateau and Gleysol in imperfectly drained areas corresponding to murundu. The Oxisol-Gleysol association determines the spatial distribution of flora and fauna of cerrado, the topography of the chapadas and the strong differences in soil carbon stocks. We hypothesize that the development of this soil landscape could generate product endowed with economic importance. In this region, the extraction of the refractory clay is exclusively located on the surface of the plateau and in Gleysol. Despite the genetic and economic interest, this soil cover and its relationships with the landscape, as well as the factors that leading the enrichment of aluminum are not well known. The main goal of this research is to determine the relationships between the evolution of Oxisol-Gleysol system and the genesis of aluminous clay deposit (kaolinite and gibbsite) found on the surface of the flat plateaus in the western of Minas Gerais State. Specifically, this research focuses on iron depletion of the Oxisol matrix by hydromorphic conditions which results in the concentration of aluminous-clay and the incision of the drainage network along the geological time. (AU)