Osning sandstone
As Osning sandstone (also Blue Stone ), a sandstone called, the regional in earlier Osning mentioned Teutoburg Forest in Germany occurs, making its "geological backbone". It is a sandstone that was deposited in the Lower Cretaceous in the Dörenther subformation at the time of the Upper Aptian to the Lower Albian. It occurs around Osnabrück , Lübbecke , Burgsteinfurt and occasionally around Bielefeld and Gütersloh . By the end of the 20th century this was rock as a construction and stone in several quarries mined.
geology
In the geological period of the Lower Cretaceous about 120 million years ago, thick sand deposits ( sediments ) formed on the edge of the Great Cretaceous Sea , which solidified to form horizontally lying sandstone and later, towards the end of the Cretaceous period about 65 million years ago, folded by tectonic processes and largely vertical were asked.
The approximately 100 meter thick Osning sandstone forms the first main ridge of the Teutoburg Forest and runs from the Egge Mountains to Ibbenbüren in a largely uniform sequence of layers. Over the course of millions of years, the rocks of the area weathered to a high degree, but the relatively hard Osning sandstone - because it was pebbly bound - formed a continuously raised layer rib , which in some places was even skeletonized into free-standing rock formations . The Osning sandstone has a strong impact on the landscape to this day and can be seen in its most imposing outcrop on the Externsteinen . There are other natural outcrops at the Dörenther cliffs and at the Teutonia cliffs near Borlinghausen .
use
The large stone grave of Rheine was created from this rock more than 4800 years ago. There were modern quarries on Dörenberg with the Bennost quarry and on Hohnsberg , which has been the subject of geological research since the 19th century.
The stone comes in two qualities. There is one deposit that is clayey and one that is calcareous. The clay variety is light yellowish, gray and rarely white. It is partly colored brown by iron oxides. This deposit is 3 to 4 meters thick. The lime-bound sandstones are usually very strong, tough and not easy to work with. Their color is blue-gray. The calcareous sandstones are partly embedded in clay layers.
literature
- A. Hendricks / E. Speetzen: The Osning sandstone in the Teutoburg Forest and in the Egge Mountains (NW Germany) - a marine coastal sediment from the Lower Cretaceous period. Treatises from the Westphalian Provincial Museum for Natural History, issue 45. Münster 1983.
- G. Keller: Where does the Osning sandstone mass of the Dörenberg massif near Bad Iburg (Teutoburg Forest) come from? in: Reports of the Natural History Society Hanover. Hanover 1979.
- G. Keller: The near-shore formation of the Osning sandstone near Bad Iburg in the lying area of the Osning thrust. in: Osnabrücker Naturwissenschaftliche Mitteilungen, Volume 6. Osnabrück 1979.
- Otto Sickenberg: stones and earth. The deposits and their management. Geology and deposits of Lower Saxony, 5th volume. Dorn-Verlag, Bremen, Horn 1951, pp. 125ff.
- E. Speetzen: Osning sandstone and Gault sandstone (Lower Cretaceous) from the Teutoburg Forest and the Egge Mountains and their use as natural building blocks. in: Geology and Paleontology in Westphalia, Issue 77, Münster, 2010 ( retrieve )
Web links
Coordinates: 51 ° 52 '8.2 " N , 8 ° 55' 2.4" E