The behaviour of rare-earth elements and Y during the rock weathering and soil formation in the Řı́čany granite massif, Central Bohemia

Autor: Martin Št'astný, Petr Skřivan, Luděk Minařík, Jiřı́ Bendl, Anna Žigová
Rok vydání: 1998
Předmět:
Zdroj: Science of The Total Environment. 215:101-111
ISSN: 0048-9697
DOI: 10.1016/s0048-9697(98)00113-2
Popis: The geochemistry of rare-earth elements (REE) and yttrium has been studied in the soil profile derived from a biotite granite in the area of `Forest Brook Catchment' (FBC) near Řicany (Central Bohemia, the Czech Republic). The comparison of the variation in the REE and Y concentrations in the individual zones of the profile shows that total content of lanthanides depends on the grain size of the soil material. The horizons abundant in clay fraction (Gr1, Gr2) contain five times more REEs than those with a predominance of silt and sand (G0, Gr3). The chondrite-normalised soil La–Lu pattern is similar in all profile zones and it behaves as an almost smooth function of the REE ionic radii, or their atomic numbers, respectively. The bulk content of lanthanides in soil is higher than that in the local partly weathered boulders of the parent rocks (syeno- and monzogranite). The content of acid soluble forms of REE (the portion of elements soluble in 0.1 M HNO3) increases from the umbric horizon A towards the bottom of the profile. Our results indicate that the mobile part of REE is leached and transported to the lower part of the profile by acidic atmospheric precipitation. The REE distribution pattern of surface- and subsurface waters draining the terrain of the catchment confirms this consideration.
Databáze: OpenAIRE