Migrace alkalických kovů ve zvětralinových profilech migmatitů ze svrateckého krystalinika a moldanubika
| Title in English | Migration of alkali metals in the weathering profiles of migmatites from the Svratka Crystalline Unit and Moldanubicum |
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| Authors | |
| Year of publication | 2020 |
| Type | Article in Periodical |
| Magazine / Source | Geologické výzkumy na Moravě a ve Slezsku |
| MU Faculty or unit | |
| Citation | |
| Web | https://doi.org/10.5817/GVMS2020-13710 |
| Doi | http://dx.doi.org/10.5817/GVMS2020-13710 |
| Keywords | migmatite; alkali metals; weathering; Svratka Crystalline Unit; Moldanubicum |
| Description | The purpose of this study was to characterize four soil profiles derived from migmatites in the Moldanubicum and Svratka Crystalline Unit (eastern part of the Czech Republic). Both physical and chemical weathering of biotite to muscovite-biotite migmatites produced 80 to 100 cm thick soil profiles. Silt (43–88%) was the dominant fraction in all of the studied soil profiles. The migmatite weathering started with replacement of biotite by hydrobiotite to chlorite and continued with the replacement of plagioclase by 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 (Na, K, Rb) we can interpret the mechanism of the formation of weathering profiles. The highest degree of the weathering indicates the soil profile from the Rovné site characterized by decreasing content of K, Na, and Rb upwards from the parent rock to the A-horizon. The soil profiles from the Lipník and Zubří sites show a higher proportion of sand fraction and lower WIP (Weathering Index of Parker; > 50) in comparison to Rovné. The vertical distribution of the alkali metals in the soil profile from the Štěpánovice site indicates that soil profile has been modified by secondary slope movements. |
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