Granites in the border area of the Czech Republic, Austria and Bavaria

Geoscience Research Reports 37, 2004 (GRR for 2003), pages 30–33

Full text (PDF, 1.07 MB)

Abstract

In the course of a new geological mapping of territory of the National Park Sumava (Bohemian Forest) at a scale of 1 : 25 000, granitic rocks in the Třístolicník area (Dreisesselberg area) were studied. The Weinsberg-type granite, the porphyritic coarse-grained two-mica granite of Třístolicník type, the equigranular coarse-grained two-mica granite of Plechý type, the fine-grained biotite to two-mica granite and durbachitic rocks were characterized mineralogically and geochemically. Within the group of durbachites, the pyroxene-biotite melasyenite (< 50 % Si02) and amphibole-biotite melasyenite (> 50 % Si02) were distinguished. Age of the Třístolicník and Plechý granites, using U-Th-Pb method on monazite, was dated at 337 ± 6.5 Ma and 347.8 ± 9.3 Ma respectively.