Argillization of topaz-bearing granites in the Hub stock, Horni Slavkov-Krasno Sn-W ore district (Bohemian Massif, Czech Republic)
Journal: Acta Geodynamica et Geomaterialia
Year: 2014

Argillized granites from the Hub stock contain a clay mineral assemblage formed by dickite, illite, tosudite and smectite. These granites occur in the upper part of the topaz granite stock, immediately beneath topaz-mica greisens consisting of quartz, clay minerals, lithium mica (protolithionite) and topaz. Argillized granites are enriched in Si (up to 78 wt.% SiO 2 ), Fe (0.5-3 wt.% FeO tot. ), F (up to 1.6 wt.%), Rb (830-1380 ppm), Li (515-2317 ppm), Nb (25-435 ppm) and Ta (21-64 ppm), but poo