About the Genesis of Brown Tropical Soils with Shallow Nonferrallitic Profile

摘要

Brown soil with a shallow nonferrallitic profile developing from various parent rocks in conditions of a seasonally humid tropical climate have been studied in Laos. It is found that these soils characterize the mature stage of tropical pedogensis on the rocks that have not been altered by presoil hydrothermal processes: in other world, these soils display all normal features of tropical pedogenesis. Red ferrallitic soils that predominate in humid tropical regions develop from hydrothermal weathering crusts.