Bressanone granite

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Bressanone granite from Franzensfeste

The Brixen granite is an intrusive body (pluton) and takes its name from the nearby small town of Brixen in South Tyrol . Petrographically , the rock is classified as granodiorite , with gabbro , amphibole granite, pegmatite and aplite dikes also occurring . The rock is also known by the trade name Meransen , after one of its mining locations near Meransen in the municipality of Mühlbach .

geology

From a tectonic point of view, the Brixen granite is located on the border between the Eastern and Southern Alps and occupies approx. 180 km 2 between Franzensfeste , Schalders , Brixen and Mühlbach . Other publications assume 250 km 2 . The periadriatic seam , the actual boundary between the two geological units, is located just a few kilometers north of Franzensfeste in the village of Mauls in the municipality of Freienfeld and in the village of Vals in the municipality of Mühlbach.

The intrusive body formed in the Permian and is therefore around 280 million years old.

At the edge of the pluton there is a pronounced contact metamorphosis to Brixen quartz phyllite , with corresponding overprinting and formation of new minerals.

Rock description and mineral inventory

It is a medium-grain, light, plutonic rock, consisting mainly of feldspar , quartz and biotite . The accompanying minerals include chlorite, epidote, zoisite , prehnite , calcite, tourmaline, garnet, fluorite, muscovite, talc and zeolite . It is black-gray to whitish. A pink variety, also known as Flagger Kalkgranit, after its occurrence in the Flaggertal, Sarntal Mountains, occurs at the edge of the intrusive body.

use

The development and mining of the Brixen granite on a larger scale go hand in hand with the construction of the Brenner railway line, which was opened in 1867. This granite is currently (2014) being mined by Pfunders . Brixen granite is mainly used regionally for floor coverings, stairs, window sills, bricks, grave borders and fountains. This natural stone is hardly traded in Germany.

This rock is of great cultural and historical importance in the region. For example, the church in Sarns , consecrated in 1510, consists of Brixen granite. Its church tower was completed in 1483.

See also

List of types of granite

literature

  • Thöny Werner Friedrich and Wyhlidal Stefan: The Permian contact metamorphosis in the southern Alps: intrusive complexes and geochronology. Dissertation, University of Innsbruck.

Web links

Individual evidence

  1. ^ F. Karl (1967): A contribution to the comparison of tonaliths and in the Central Bohemian pluton and periadriatic intrusive masses , p. 6 ff., Ed. from the Mineralogical Institute Kiel
  2. a b Geology of the Dolomites: The Brixner Granite and the Battle for Tyrol - Bressan-Geoconsult. Retrieved June 22, 2019 (German).
  3. Maranza at natursteinonline.de. Retrieved November 12, 2014
  4. a b Granite of the Alps on ged.rwth-aachen.de. Retrieved November 12, 2014
  5. A piece of the South Tyrolean Alps on natursteinonline.de. Retrieved November 12, 2014