Ihrlersteiner green sandstone
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The Ihrlerstein green sandstone , also known as Regensburg green sandstone or Green Danube sandstone , is a green to green-brown sand-lime stone with fossil fragments. This green sandstone was created in the Upper Cretaceous in the Cenomaniac .
Occurrence
In the area of Regensburg , a green sandstone is with a thickness of 10 to 15 meters on the Jurassic limestone, which in the Middle Ages and under the Bavarian King Ludwig I. north in numerous quarries of Kelheim in Frankenalb in Lower Bavaria earlier and around room broken has been. The numerous fractures were near Bad Abbach- Oberndorf, Kapfelberg, and Kelheim and southeast of Amberg near Hiltersdorf , Högling and Wolfering . In 2008 there was only one quarry in operation.
Petrographic description and naming
Its color impression is light gray to olive gray. It is a fine-grained glauconitic sandstone with fossil fragments that are irregularly distributed in the rock.
The Ihrlerstein green sandstone consists of 63 percent quartz , 15 percent glauconite , 11 percent rock fragments, 5 percent fossil remains, 3 percent alkali feldspar , 3 percent zircon , rutile and opaque ore. Glauconite is responsible for the green color. The sandstone is mainly bound carbonate .
The name of the stone and the place Ihrlerstein goes back to Jakob Ihrler (1791-1852), the master stonemason and quarry owner in Ihrlerstein.
Weathering behavior and use
Its weathering behavior essentially depends on the rock layer from which the stone was taken. This can be noticeable in sanding, fading and peeling. Stripping in the open air occurs shortly after installation, as does plaster crust formation . This natural stone is not resistant to aggressions.
This sandstone can be used for solid buildings, stone carving , wall panels and monuments. This stone is particularly suitable for massive stone work. This natural stone fell into disrepute under Ludwig I because it was badly weathered. However, this was due to the fact that the right selection was not made in the quarry, because there are weatherproof layers. Ihrlersteiner green sandstone was probably used since Roman times . It was installed at the Regensburg Cathedral , the Stone Bridge in Regensburg , the Neue Pinakothek , the Alte Pinakothek and Residenz in Munich as well as for the Liberation Hall in Kelheim , the Sparkasse Kelheim and the Lion Monument in Bad Abbach .
In the run-up to the planned renovation of the Stone Bridge , an extensive search was carried out in 2009 for suitable stone material that can be used for the renovation. It should match the original material in terms of color and structure and also have sufficient strength and weather resistance. They finally found what they were looking for in an abandoned quarry near Ihrlerstein .
Geotope
The green sand quarries near Ihrlerstein are designated by the Bavarian State Office for the Environment as an important geotope (geotope number: 273A029).
Web links
literature
- W. Dienemann and O. Burre: The usable rocks of Germany and their deposits with the exception of coal, ores and salts, Enke-Verlag, Stuttgart 1929, p. 287.
- Wolf-Dieter Grimm: picture atlas of important monument rocks of the Federal Republic of Germany. Published by the Bavarian State Office for Monument Preservation, Lipp-Verlag, Munich 1990, ISBN 3-87490-535-7 , rock no. 130.
Individual evidence
- ↑ Grimm: Pictorial Atlas of Important Monument Rocks, Rock No. 130 (see literature)
- ↑ Bavarian State Office for the Environment, Geotop green sand quarries near Ihrlerstein (accessed on October 17, 2017).
- Art-historical use of Ihrlersteiner Grünstein
Regensburg Cathedral
Old Pinakothek in Munich
Balustrade at the Kelheim Liberation Hall
