Obernkirchen sandstone

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Obernkirchen sandstone
Milled surface of the Obernkirchen sandstone
Milled surface of the Obernkirchen sandstone
Main features
group Sedimentite
Subgroup Sandstone
Occurrence Germany, Lower Saxony
colour gray-white to yellowish-white
use Stone, facade cladding, floor coverings

Dismantling situation recent degradation
Division into hard and soft stone Soft rock
Age Lower Cretaceous
Reference example Bremen City Hall , Vladimir Palace
Special marks white spots containing kaolinite
Template: Infobox natural stone / maintenance / trade name is missing

The Obernkirchen sandstone is named after the town of Obernkirchen am Bückeberg in northern Germany. The sandstone broken there is also called Bückebergsandstein and Bremer Stein because it was often built in Bremen or shipped there on the Weser . It belongs to the group of Wealden sandstones , a sandstone deposit in northwest Germany, which was created in the time of the Berrias (also called " Wealden " or "Wälderton" according to the facies ). In this sequence of layers, fossils or traces of fossils appear quite often, such as the traces of dinosaurs found in the Obernkirchen sandstone quarry in 2007 .

History and culture

Since the foundation of the monastery and the construction of the Romanesque monastery basilica in 1167, the breaking and processing of sandstone from the ridges of the Bückeberg have determined the history of Obernkirchen .

Obernkirchener sandstone was not only used as stone on buildings and for well surrounds. B. used in the Bremen rural area, but is also used as a sculptural stone. Due to its high quality, this natural stone has often been used for sculptures and modern stone designs. The texture of the stone is fine-grained and compact, so that the stone is suitable for the finest sculptural work.

A large part of the stones broken near Obernkirchen was shipped on the Weser to Bremen and transshipped here. That is why it was also transported by sea to other countries as the so-called Bremer Stein , as far as the Netherlands, Denmark, Sweden, Norway, the Baltic States, Switzerland and America. In Bremen itself it was called "Grauwerk" until the 19th century.

Occurrence and mineralogy

Monument to Otto Linne in the Ohlsdorf cemetery made of Obernkirchen sandstone

This sandstone is found between Obernkirchen and Stadthagen in the Bückeberg Mountains. It is a closed occurrence with a thickness of 12 to 15 meters. The bench height on the Harl is 16 meters and decreases to 2 to 3 meters in the west. The thick bank allows the extraction of large blocks. In the north, the occurrence merges into the Liekweg sandstone.

The Obernkirchen sandstone is a fine-grained quartz sandstone with a pebbly binder. Its quartz content is 99 percent with quartz 81 percent and rock fragments 17 percent. Chance are decomposed serizitische admixtures of muscovite and heavy minerals with 1 percent. The heavy minerals are zircon , tourmaline , rutile , apatite , opaque grains.

The stone has a yellowish-gray color, in part there are textures that make the stone streak-like. The yellow color is caused by the mineral limonite and the gray color by carbon components. Due to the current environmental conditions, limonite is dissolved in the stone and migrates to the outer surfaces of the stone, which are exposed to weathering and darken. This process has no effect on the strength of this sandstone. Its weather resistance and frost resistance is extremely high. This sandstone has been mined for around 1,000 years and even centuries later only minor weathering could be observed on the collegiate church in Obernkirchen (1153–1167). Furthermore, due to its durability , this natural stone is suitable as a so-called water building stone for the expansion of shipping canals.

Stone surfaces

  • Obernkirchen sandstone, machine-scratched (pattern approx. 25 × 15 cm)

  • Obernkirchen sandstone, hewn (pattern approx. 25 × 15 cm)

  • Obernkirchen sandstone, milled (pattern approx. 25 × 15 cm)

Building list

Antwerp City Hall
Kaliningrad Stock Exchange
Bremen town hall with Roland

Some buildings for whose construction or restoration Obernkirchen sandstone was supplied - sorted by country and by distance from the quarries:

See also

literature

  • Robert Kain: Obernkirchen sandstone - a material from the Weserland. Self-published by the company Obernkirchener Sandsteinbrüche Paul Ebeling, undated (approx. 1938). (pdf 7 MB)
  • Otto Sickenberg: The deposits of Lower Saxony and their management , vol. 5., ed. by Kurt Brüning, Lower Saxony Office for State Planning and Statistics. Dornverlag. Bremen, Horn 1951.
  • Dieter Poestges: The history of the Obernkirchener sandstone quarries , in: Bremisches Jahrbuch , Volume 60/61, Bremen 1982/83, pp. 95-116.
  • 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 .
  • Elisabeth-Kuster-Wendenburg: The Bremen stone and the dinosaurs . Aschenbeck & Holstein Verlag, Delmenhorst 1999, ISBN 3-932292-18-9 . (pdf 38 MB)
  • Karlfried Fuchs: Natural stones from all over the world. Callwey stone card index in 2 volumes , Callwey-Verlag, Munich 1997, ISBN 3-7667-1267-5

Web links

Individual evidence

  1. ↑ H.-H. Meyer, water supply in the land area, in: water, on the history of drinking water supply in Bremen , Focke-Museum: Bremen 1988, pp. 98-100