A HYPOTHETICAL MODEL OF ELUVIAL HORIZON DEVELOPMENT IN SOILS AND WEATHERING CRUSTS

An ideal model of the eluvial process in freely drained soils and weat hering crusts, which is suitable for all the humid areas, has been dev eloped. A process of chemical decomposition of an ''ideal'' sandy pare nt material, with only two ingredients, by a continuous downward flux containing aggressive ''fulvo'' substance has been developed. One comp onent--plagioclase--is subjected to congruent dissolution with removal of all the solutes beyond the eluvial layer. The other ingredient-qua rtz-is relatively (residually) accumulated DI situ within the eluvial zone. The eluviation interface has been the major study object in this model in terms of its characteristic depth and translocation rate.