Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Contribution to petrochemistry of Late Variscan felsitic granite porphyries from the Moldanubian Zone, Bohemian Massif
Abstract
New finds of felsitic alkali-feldspar granite porphyry occur at the apical part of the Stožec Hill, near Lenora, Moldanubian Zone, southern Bohemia. The dykes a few cm/dm thick penetrate host durbachitic rocks and mica-tourmaline granite. The granular structure of the groundmass indicates devitrification of former glassy rocks with a rapid solidification of granite melt under shallow subsurface conditions. Chemical analyses show high contents of SiO2, Al2O3, Na2O, P2O5, low contents of MgO and CaO, enrichment in Rb, Th, U, and relative depletion in Sr, Y and Cr. The felsitic granite porphyry belongs to the latest Variscan granitoid intrusions in this part of the Moldanubian Zone.
