Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Accessory minerals of ABO4-type from some subvolcanic equivalents of A-type granites from the Krušné hory/Erzgebirge Mts. and from the Teplice rhyolite
Abstract
In the frame of systematic study focused on the A-type Variscan granitoids in Krušné hory Mts./Erzgebirge, we have studied radioactive accessory minerals of ABO4-type from (i) subvolcanic rhyolitic dykes near Gottesberg (Germany), (ii) altered granite porphyry dyke from Schneckenstein (Germany) and (iii) effusive rhyolite from the Teplice caldera (Czech Republic). Metamict zircon rich in xenotime component is the most common accessory phase in all examined samples. Thorite occurs particularly in the Teplice rhyolite, while concomitance of monazite with xenotime and pure zircon is typical for the Schneckenstein granite porphyry dyke. The assemblage from Schneckenstein differs from all other A-type granitoids in studied area and it is addressed the question about genetic affiliation of this rock.
