Pollinger tufa
The Pollinger Kalktuff , also called Pollinger Tuff or Polling for short , is a freshwater limestone that is mined near Polling , a municipality in the Upper Bavarian district of Weilheim-Schongau . It is the only tufa extraction in Bavaria that is still in operation today (2014). Limestone tuffs are widespread in the Bavarian Alpine foothills and have been mined in numerous places. Most of the deposits are now (2014) exhausted. This tufa originated in the Pleistocene .
Occurrence
The Pollingen tufa was created on the threshold of a lake that no longer exists today. There are assumptions that the threshold at the water levels in the Ammersee area was formed in the high and late glacial of the Würm glacial period . Calcareous waters flowed over the threshold and lime (CaCO 3 ) was precipitated , which was deposited as tufa .
Rock description
The beige Pollinger tufa consists of lime-coated reeds, grasses, mosses, leaves and other freshwater plants as well as water mollusks. Pollinger Kalktuff has large pores. Large-pored areas alternate with dense ones.
In addition, artifacts of lime were encrusted in this rock deposit , which indicate that the area was already 3500 BC. Was settled.
use
This natural stone is frost-resistant. Pollinger Kalktuff, like all Kalktuffe, is not resistant to aggressions and cannot be polished. Installed as a brick, it achieves good insulation values when dry, but walls were also plastered. The result is that the insulation is considerably restricted because these store water and only release it slowly. The large pores of this limestone tuff can, if necessary, also be cemented with special compounds and thus closed.
Numerous old farmhouses, churches and monasteries in the neighboring villages of Polling have been built from this tufa. It was used locally primarily as a brick, door and window reveals , but also for decorative elements, for example on the portal of the Polling monastery . In the vicinity of Polling, this tufa was used as a fountain in Peißenberg , Murnau and Pähl .
The historic city walls in Weilheim or Schongau , the grotto of Linderhof Palace , facade elements of the Müller Volksbad , the Hohenpeißenberg meteorological observatory and the old trade fair tower in Munich are made from Pollingen tufa. This tufa was also used for garden design, such as for the Alpinum and for balustrades in the Botanical Garden in Munich-Nymphenburg , as well as for the construction of the Alpinum next to the royal house on the Schachen in the Wetterstein Mountains . Even today, parts of the facade and eaves at the Frauenkirche in Munich are replaced with this soft stone as part of restoration work .
The cornices of the Frauenkirche in Munich are made of Pollingen tufa.
Façade elements made of Pollinger Tuff structure the Müllersche Volksbad .
The city wall in Schongau (plastered in the foreground) consists of Pollingen tufa.
The tower of the Hohenpeißenberg Meteorological Observatory was built from Pollingen tufa.
The balustrade (right and left in the foreground) in the Botanical Garden in Munich-Nymphenburg was made from Pollingen tufa.
The Alpinum in the Botanical Garden in Munich-Nymphenburg was built from Pollingen tufa.
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Dismantling
It is known that there were two quarries, today only one is in operation on an area of 5000 m². Traditionally, tufa was loosened with the help of stone splitting tools and levers . Pollinger Kalktuffe, a soft rock , can be shaped and worked like other limestone tuff when broken with stone axes or a hand saw. Two workers move a long saw over the rough stones. Above all, bricks could be made with this tool. Today this rock is loosened from the deposit with a mobile, fuel-driven sword saw , whereby rough blocks up to a maximum of 1 m² can be extracted due to the fissures in the rock. Overburden is moved with an excavator, as are rubble stones . The further processing of the raw blocks is done with a stone circular saw .
literature
- The formation of the tuff and the limestone tufa deposits. In: Max Biller: Pollinger Heimat-Lexikon. Polling 1992, half volume 1, pp. 343-345
Web links
- Stone pattern of the Pollingen limestone tuff on natursteinonline.de
- Exhibition about the origin of the Pollingen limestone tuff in the Museum Polling
- Illustration of the memorial stone 1000 years of Aubing made of Pollinger tufa
Individual evidence
- ↑ a b The local history of Etting , on polling.de. Retrieved December 12, 2014
- ↑ a b Ludger Feldmann: Former water levels in the Ammersee area in the high and late glacials of the Würm ( Memento of the original from December 13, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . In. Ice Age and Present . S. 53. Yearbook 1992. Hanover
- ↑ a b Look here - beautiful and unpredictable : Economy - the IHK magazine for Munich and Upper Bavaria . Issue 9/2012, ed. from the IHK Munich Upper Bavaria. Retrieved December 12, 2014
