Teutoburg Forest sandstone
Teutoburgerwald sandstone , also known as Neocom sandstone , Kammsandstein , Bielefelder sandstone and Gravenhorster sandstone , occurs near Rheine , Bad Iburg , Bielefeld , Gütersloh and Detmold in an area of the Egge Mountains and the Teutoburg Forest in North Rhine-Westphalia . The Teutoburgerwald sandstone originated in the Lower Chalk in the Neokom and should not be confused with the Osning sandstone , which was also formed in the Lower Chalk, but mainly in the Wealden (forest clay). There are three types of Teutoburg Forest sandstone: Velmerstot type, Grotenburg type and Ebberg type.
Rock description
The color of these sandstones ranges from gray-white and yellow to red. Now and then he shows Liesegang's rings ; but it is also rust-colored, brown to purple in color. In the Osning the occurrence can be colored green by glauconite . Its grain is fine to medium-grained. Its bond is mostly clayey-limonitic, with clayey bonds predominating. A partially quartzitic bond is rare, except at Gravenhorst where the Gravenhorst sandstone was broken, which is quartzitic and therefore more weatherproof. This is especially true for the occurrence in the north-western part of the Teutoburg Forest. A carbonic bond of the rock layers is found in the southeastern Osning. In addition to quartz and rock fragments, there are accessories such as zircon , spinel , tourmaline , heavy metals and garnet . Feldspar is rare, as is pyrite . Some of the layers are conglomerate with larger grains and rock fragments .
Occurrence and types of sandstone
The occurrence can include continuous banks up to 8 meters, flat storage is rare. The conglomerate banks are up to 5 meters thick. In the Ravensberger Hügelland and in the eastern Teutoburg Forest the layer height is up to 40 to 60 meters, at Horn-Bad Meinberg and Detmold 40 to 60 meters and in the Osning the rock deposits reach 200 to 360 meters and sink in the northeast. In some cases, parts of the plant were stored during the development process, which precipitated and caused holes in the rock.
The best-known deposits are in Bevergern , Gravenhorst , Riesenbeck and Dörenberg .
use
This sandstone was used as stone for high-rise and bridge constructions, as curb and memorial stone, for facing bricks and stone carving work . This stone has been quarried since the Middle Ages. In 1938 there were two large and six small businesses with around 240 employees, and after the Second World War it was not possible to match these business figures.
Teutoburg sandstone, Velmerstot type
The quarry is located on the Velmerstot mountain near Horn-Bad Meinberg in the southeastern Teutoburg Forest and will no longer be dismantled in 2008. It is a light gray, partly brown-banded sandstone from the Neocom , which is partly clayey and partly quartzite. It consists of 85 percent quartz , 13 percent rock fragments and 2 percent feldspar , with muscovite and heavy metals as an accessory. This sandstone was used for solid buildings, facades and portals as well as for monuments. The castle, state theater and district court in Detmold , Horn-Bad Meinberg and Lage are made of this sandstone, as are numerous churches and stone houses in the Detmold area.
Teutoburg sandstone, Grotenburg type
The sandstone type Grotenburg is no longer being mined in 2008 and was extracted on the Grotenburg mountain near Detmold. It is a light gray sandstone with brownish flames. It is a quartzite-bound natural stone . It consists of 98 percent quartz, 2 percent rock fragments and accessory parts of heavy metals. Its quartz bond makes it very weather-resistant. It was mixed with the Velmertot type and installed on the above-mentioned structures.
Teutoburg sandstone, Ebberg type
The one on the Ebberg mountain in the southeastern Teutoburg Forest near Bielefeld was mined . The deposit was no longer mined in 2008. It is a sandstone with fine sand and loosened plant parts. It is clayey-limonitic and not very quartzitic. Its mineral content: quartz 94 percent, rock fragments 4% and 2 percent feldspar. It was installed at the Neustätter Marienkirche and at the Ratsgymnasium in Bielefeld, as well as on numerous buildings in Bielefeld's old town and as tombstones in the Jewish cemetery in Borgholzhausen .
literature
- 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 .
- Otto Sickenberg: stones and earth. The deposits and their management. Geology and deposits of Lower Saxony. 5th volume. Dorn-Verlag, Bremen, Horn 1951, p. 78ff.