Tertiary quartzite
As tertiary quartzite (including freshwater quartzite ) is defined as contiguous gravelly compacted sandstone layers to solid quartzite or individual boulders bearing (small bulbous body to large boulders) by the silicification Cretaceous or Tertiary sands have emerged. Knollenstein is an outdated name .
Rock and formation
Tertiary quartzites are very dense and hard, break splintery and are usually whitish, light gray, yellowish or brownish in color. The surface is often bulbous-kidney-like, in some occurrences remains of the original stratification have been preserved.
The quartzites are by the silicification of sand under semiarid created conditions by in near-surface layers of silica in precipitation water has been solved, penetrated with the percolating water into deeper layers, where at appropriate chemical conditions in the form of quartz for precipitation came. During the precipitation, the sands originally present there were connected by the quartz to a solid, quartzitic rock. This process is commonly referred to as cementation .
The individual boulders that occur frequently in different areas are remnants of formerly more or less coherent layers of sandstone, which have largely disappeared today due to weathering. It is not about erratic boulders that were left behind by glaciers . Due to the hardness of the rock, remnants of tertiary quartzites form a scattering of quartzite gravel and pebbles in some areas, for example in the Eifel or in the Lahn area .
Occurrence
Individual tertiary quartzites are often found at higher altitudes in the German low mountain ranges . One example is the White Stone near Udenbreth in the municipality of Hellenthal in the Eifel in the Belgian municipality of Büllingen , from which the Am Weißen Stein ski area owes its name. A large single chunk of tertiary quartzite was found in Billig near Euskirchen in July 2004 . Its weight is about 15 tons . Further occurrences of tertiary quartzites are known as Cyclops stones on the German-Belgian border in the south of Aachen . In the Upper Palatinate and in the Franconian region, such quartzitic formations are known as Kallmünzer . The largest Kallmünzer is the Zyprianstein .
Chunks of tertiary quartzites were repeatedly found on the Vogelsberg during the mining of tertiary sands, and so-called lignite quartzite was also used as a building block in the Westerwald . Further occurrences are known from the area around Leisnig , near Waldenburg or Kupferberg . Tertiary quartzites also occur in connection with lignite mining in the Leipzig region , for example near Borna , Witznitz and Profen as well as Berzdorf and Nochten , as well as in northern Bohemia or in the Lower Rhine Bay area . Near Herzogenrath in the west of the Lower Rhine Bay, tertiary quartzites were still being mined in the 20th century ( Nievelstein sandstone ).
use
Due to their hardness, tertiary quartzites were used as building blocks if they could be mined in larger deposits - as in connection with lignite mining. Quartzites with a content of over 96% SiO 2 are used in the refractory industry, for example for furnace linings. The hardness of the rock was also the reason for its use by prehistoric settlers in areas with occurrences of tertiary quartzites, such as the area of the Middle Rhine .
The hardness and wear resistance also made freshwater quartzite a preferred rock for making millstones . The so-called "French" or "Champagne stones" made from freshwater quartzite from Champagne , especially from the quarries near La Ferté-sous-Jouarre, are particularly famous .
literature
- W. Pälchen / H. Walter (Ed.): Geology of Saxony. Geological structure and history of development . Stuttgart (Swiss beard) 2008 ISBN 978-3-510-65239-6
Individual evidence
- ↑ Pälchen, Walter: Geology of Saxony, 2008 p 418
- ↑ Heinz-Martin Möbus: Allochthonous Triassic clods on the Unterwerrasattel as a key to understanding Saxon rift tectonics . Dissertation at the Institute for Geology and Paleontology of the Geosciences Department of the Philipps University of Marburg. 2004, p. 51 ( online ).
- ^ Roland Walter: Aachen and the northern area . In: Geological Guide Collection Volume 101 . Gebr. Borntraeger, ISBN 978-3-443-15087-7 .
- ↑ Vogelsberg volcano: tertiary quartzite . Retrieved on April 22, 2009. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ a b D. Beeger: Brown coal quartzite and lawn iron ore - occurrence and use . In: natural stone . 1997. ISSN 0028-1026 . ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ^ W. Pohl: W. & WE Petrascheck's deposit theory . 4th edition. Schweitzerbart, Stuttgart 1992, p. 289 .
- ↑ Harald Floss and Thomas Terberger: The stone artifacts of the Magdalenian of Andernach [Middle Rhine]. The excavations 1979-1983 . In: Nicholas John Conard et al. (Ed.): Tübingen works on prehistory . ISSN 1438-8618 ( vml-verlag.de ).
