Mineral Composition in Rhizosphere of Plants Grown in the Vicinity of a Zn-pb Ore Flotation Tailings Pond. Preliminary Study

Mineral forms in rhizosphere and bulk substrate were examined for selected plant species (Cardaminopsis arenosa, Calamagrostis epigeios, Deschampsia caespitosa, Festuca ovina, Silene vulgaris, Viola tricolor) growing spontaneously in the close vicinity of a tailings pond and in a zone of eolian transmission of waste particles. Samples of substrates and plant roots were taken from sites in the Bolesław orefield near Olkusz. The substrates together with plant roots were studied by scanning electron microscopy coupled with energy dispersive spectroscopy. Apart from quartz and carbonates, the most frequent mineral phases found were crystalline and amorphous Fe oxides, as well as primary Fe, Zn and Pb sulphides (marcasite, pyrite, sphalerite, galena). Hydrated Ca, Mg and Fe sulphates (gypsum, epsomite and melanterite) and other secondary minerals (smithsonite, cerussite, otavite, and Fe, K and Mg aluminosilicates) were found at larger concentrations in the rhizosphere than in bulk soil, suggesting that plant roots can change the mineral composition of the soil.