Axinite Localities in the Proterozoic Unit of Barrandian in the Vltava (Moldau) Valley, South of Prague, Czech Republic
- Author:
- Dalibor Velebil – National museum, Prague, Czech republic
- Source:
- Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha) 8 (2000), 180–183
Abstract
The Proterozoic Unit of Barrandien located south of Prague is formed by a low-metamorphosed greywacke and siltstones, i.e. volcanic and volcanosedimentary rocks. Frequent occurrences of axinite in this area are associated with thick veins of andezite. The second Czech locality where axinite was described in 1942 is the abandoned quarry Hubatka in Zbraslav-Zabehlice, where a sheer zonal axinite-calcite vein of the thickness of 12 cm in direction NNW – SSE appears. Crystals of well-developed ferroaxinite of the size of approx. 3 cm grows to the center of the vein. Sub-vertical veins of axinite with quartz and calcite of the average thickness about 10 cm appeared during mining works in a quarry of Kamen Zbraslav s.r.o. The same type occurrences of axinite in this area are: the quarry nearby Vrane nad Vltavou dam, Davle, Sazava, Hradistko-Mandat and Stechovice-Brunsov (the dam). Axinite veins are produced by Proterozoic post-volcanic hydrothermal process or their origin is associated with post-plutonic remobilization of rock substances, during which trace content of boron was leached from the Proterozoic rocks.
Keywords: axinite, Barrandian, Proterozoic Unit, topographical mineralogy