Wirbelau marble
The Wirbelau marble , which is also known as Wirbelau , is a geological limestone that was mined around Wirbelau in the Limburg-Weilburg district in Hesse . This dark gray limestone, which contains numerous fossils, was widely used by stone carvers. This type of natural stone belongs to the group of numerous Lahn marbles and originated as reef limestone in the Upper Devonian .
Occurrence
The Wirbelau marble was created in the Limburg Basin , a warm, moving sea that represents a subsidence area within the Rhenish Slate Mountains . This limestone is part of the Central Devonian mass limestone , the Lahn marble . The Limburg Basin lies between the Gießen-Koblenzer-Lahntal, the Weilburger Lahntal area and the Lower Lahn valley on both sides of the Lahn around the city of Limburg.
The term "marble" for the Wirbelau marble is not correct from a geological point of view, since it is a carbonate rock that has not been converted into a marble . Since this “marble” can be polished and because it has a marbled texture, the usual designation marble can definitely be seen and used as a traditional cultural term. The lively Lahn marbles are mainly black, gray and red. But they also show mixed colors that almost go as far as white.
Rock description
The Wirbelau marble is gray and dense. It contains fossilized armpods , echinoderms such as sea lily stalk limbs, trochites , corals , bog animals and foraminifera . The petrified fossil remains have different sizes and are irregularly embedded in this rock, the sizes are between 0.2 and several centimeters. Its components are 40 to 50 percent and the binders 50 to 60 percent. Quartz grains are very rarely included. The gray color results from the organic carbon content.
use
Mining began only after 1900 and was operated in two quarries. This limestone was used in architecture for solid pieces, floor and stair coverings, tombs and for stone carving. The dismantling stopped after 1965/66.
Numerous gravestones from the Kassel cemetery are made of this stone, the King Konrad monument in Weilburg, the altar and ambo in the church of Ahlbach . The limestone was also used in the entrance to the old Hessische Landesbank and in the S. Gallus church in Flörsheim and in the chancel of the Speyer Cathedral .
During manual processing, hydrogen sulphide is released and a rotten egg smell arises. However, the concentration is so low that there is no harm to health and this effect does not occur after processing. The natural stone can be polished, but the outdoor polish wears off relatively quickly. Its weathering behavior outdoors can be described as good to moderate.
Altar in the church of Ahlbach made of Wirbelau marble
Base of an Ahlbach field cross made of Wirbelau marble with a cross made of diabase
Web links
Individual evidence
- ^ Wolf-Dieter Grimm, picture atlas of important memorial stones of the Federal Republic of Germany, ed. from the Bavarian State Office for the Preservation of Monuments, Rock No. 156, Lipp-Verlag. Munich 1990. ISBN 3-87490-535-7
- ↑ Thomas Kirnbauer: Nassau Marble or Lahn Marble - a famous Devonian dimension stone from Germany ( Memento from May 16, 2011 in the Internet Archive ). In: SDGG, series of publications by Dt. Ges. F. Geoscientific Issue 59, 2008, p. 199
- ↑ Tomb created by Gunnar Ravn
- ↑ Information on www.weilburg-lahn.info
- ↑ information from www.ahlbach-online.de