Weinsberger granite
Weinsberger granite is a very coarse-grained granite that is widespread in the Waldviertel and Mühlviertel . It is part of the South Bohemian Pluton , which, with an area of around 6000 square kilometers on the earth's surface, is one of the largest intrusive bodies of the Variscan orogeny .
Occurrence and distribution
The distribution area of the Weinsberg granite is in the western Waldviertel from the Danube to just north of Gmünd and in the eastern, lower Mühlviertel to Mauthausen , which is around 1000 km² more than the area of the eponymous Weinsberger Forest . The backs of the Weinsberg forest consist mostly of Weinsberg granites, which are mostly typical here. Some elongated and narrow foothills can also be traced through the Mühlviertel to Bavaria .
description
The Weinsberger granite is a coarse-grained granite with coarse to giant tabular potash feldspars, so that the much finer-grained intermediate mixture of biotite, oligoclase, microcline and quartz represent only a subordinate abundance. The fresh rock is gray, the beginning of weathering turns the granite brown to red-brown. The potash feldspars can be easily removed from the granite, which leads to wool sack weathering . With its strong weathering ( gravel ), in which the rock ultimately breaks down into sand, it contributes to the typical appearance of the western wall district ( Blockheide Ysperklamm ).
Naming
The geologists Leo Waldmann and Alexander Köhler named the rock after the Weinsberg Forest after it had changed its name several times over the course of 100 years (porphyry-like granite, porphyry granite, porphyry granite, A-granite, crystal granite, old crystal granite).
use
Weinsberg granite was mainly used as cut and cut stone only in the absence of other stones and only in the local context. Although it is easier to work with than Mauthausen granite, it burrows very quickly. Today it is only mined to a limited extent and used as quarry stone for road construction.
literature
- Gerhard Fuchs, Alois Matura: On the geology of the crystalline of the southern Bohemian mass , in: Yearbook of the Federal Geological Institute, Volume 119, Vienna 1976, pp. 15–17 PDF
