EN
The pedogenic process of humus accumulation causes stronger and more diverse chemical rather than physical transformations of quartz grain surfaces. Chemical weathering of quartz grain surfaces in the humus horizon results in etching and corrosion over oncrusting and encrusting; an opposite situation is observed in the parent rock and the underlying rocks. Etchings and corrosion pits in the humus horizon were formed in the pedogenic process of humus accumulation, whereas oncrustings and encrustings in the parent rock and the underlying rocks are of geological origin. Microchemical analysis (EDS) indicated the highest total content of Si, Ca, Al and Fe in the oncrustings and encrustings on quartz grains.