Hottenstein (rock)

from Wikipedia, the free encyclopedia

As Hottenstein a profound decalcified is Cenomanian - pläners referred, which during the Upper chalk - tertiary time - weathering especially in southern Münsterland of the northern edge of the Rhenish Massif has formed. Here, together with insoluble constituents and Pleistocene loess, it forms an Eemzeitigen weathering clay, the Hottenstein silt loam.

Formation of hot stones

During the Upper Cretaceous and Tertiary Periods, the limestone and marl stones under tropical climatic conditions were deeply weathered and decalcified. The result of this decalcification was the formation of the light, porous hot stones. The insoluble constituents of the Cenomanian plans, together with Pleistocene loess that was blown in from the north, formed a residual clay that mixed with the Hottenstones and is known as Hottenstein weathered clay. The formation of these weathering stones began in the older Tertiary. During the warm periods in the Pleistocene , the Hottenstein weathering silts were partially redistributed solifluidally several times .

Rock description and mineral inventory

The light yellow to brownish colored hot stones are often characterized by concentric brownish-red to orange-brown iron oxide precipitates. A relatively solid, mostly only weakly weathered rock core is surrounded by a spongy-porous weathering bark. The Hottensteine ​​consist of a rock skeleton, which usually consists of amorphous to finely crystalline silica with small proportions of clay minerals (mainly illite and kaolinite ) and mineral relics , including calcite and dolomite .

The Cenoman plan areas in the southern Münsterland are affected by decalcification to different degrees. The hot stone formation is usually based on fissures and layers . To explain the intensive weathering of the lying parts of the Cenoman plan, the permanent water stagnation on the more impermeable Cenoman marls , which underlie the Cenoman plan over a large area, could be used. The lower sections of the PLANER limestone were therefore always in the area of ​​the groundwater and were therefore loosened particularly quickly. The silicic acid released during the weathering of the clay minerals stiffened the rock structure so that the limestone and limestone marl could not be completely dissolved. Large parts of the Plänerplaten area of ​​the southern Münsterland are characterized by the occurrence of "Hottensteinschlufflehm".

literature

  • Eckehard von Zezschwitz: On the history and socialization of typical soils on the Paderborn plateau . Decheniana, Volume 118, Bonn 1967, pp. 222-234.
  • Hans Mertens: About loess loam and so-called weathering loam on Hellweg, on the Haarstrang and the Paderborn plateau , Spieker, Heft 37, Münster 1991, pp. 43–54, pdf in: [1] (PDF; 1 MB)

Individual evidence

  1. ^ Eckehard von Zezschwitz: On the history and socialization of typical soils on the Paderborn plateau . Decheniana , Volume 118, Bonn 1967, p. 222ff.
  2. ↑ a b Eckehard von Zezschwitz: The soils of the Hardehausener Forest (forest district Neuenheerse) , Krefeld 1988.
  3. ↑ a b Jochen Farrenschon, Béatrice Oesterreich, Sven Blumenstein and Michael Holzinger: Geological Map of North Rhine-Westphalia, 1: 25,000, sheet 4519 Marsberg , Krefeld 2008, p. 155f.