Migrace alkalických kovů ve zvětralinových profilech migmatitů ze svrateckého krystalinika a moldanubika

Abstract

The purpose of this study was to characterize four soil profiles derived from migmatites were studied in the Moldanubicum and Svratka Crystalline Unit (eastern part of the Czech Republic). Both physical and chemical weathering biotite to muscovite-biotite migmatites produces 100 to 80 cm thick soil profiles. The silt (43–88 %) was the dominant fraction in all of the studied soil profiles. The weathering process studied migmatites start with biotite replaced to chlorite and continue decomposition plagioclase to the kaolinite. On the other hand, K-feldspar is less affected by secondary alterations and quartz is stable. Based on the study of the behavior of selected alkali metals we can interpret the mechanism of the formation of weathering profiles. The highest degree of the weathering indicates soil profile from the locality Rovné characterized by decreased content of K, Na, and Rb upwards from the parent rock to the A-horizon. The soil profiles from the localities Lipník and Zubří shows a higher proportion of sand fraction and lower WIP (> 50) in comparison to Rovné. Vertical distribution of alkali metals in the soil profile from the locality Štěpánovice indicates that soil profile has been modified by secondary slope movements