Gerolsteiner Kalkmulde

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The limestone basins of the Eifel on the line between the Lower Rhine Bay in the north and Trier Bay in the south.

The Gerolsteiner Kalkmulde or Gerolsteiner Mulde is a landscape area at the southern end of the Kalkeifel , which in turn is assigned to the Eifel . The Gerolsteiner Mulde is one of the smallest limestone hollows in Eifler . In the deep valley of Kyll between Pelm and Lissingen rise up to 100 meters above the valley Gerolsteiner dolomites, a Devonian Kalkriff that of the extinct Rugosen , Tabu distillates and stromatoporoids was formed with the Hustley, the Munterley and the Auberg. They dominate the Gerolstein townscape .

Munterley in the background with the Gerolsteiner Erlöserkirche in the foreground

In the 19th century there were even plans to dismantle the rock formations and use them to make gravel. The plans were never realized and since 1990 the area "Auberg, Munterley, Hustley, Papenkaule and Juddenkirchof" has been a nature reserve .

Geography and geology

The Gerolsteiner Kalkmulde is about 1/3 west and 2/3 east of the village of Gerolstein, south of the Hillesheimer Kalkmulde from which it is separated by the Essinger Sattel. To the west, the Birresborn saddle area separates the Prümer Kalkmulde and to the south the same ridge separates the small Salmerwald Kalkmulde from the Gerolsteiner. To the northwest, the limestone basin, like the southern tip of the Hillesheimer and the northeast corner of the Prümer Kalkmulde, blends unclearly into the Oberbettinger red sandstone region. There remains of Triassic sediments overlay the Devonian layers. Like all Eifel limestone troughs, the Gerolstein limestone trough runs roughly from southwest to northeast. In this direction, from the Gerolstein district of Hinterhausen to Hohenfels , the Mulde is approx. 12 km long. At the widest point between the Gerolsteiner districts Gees and Bewingen approx. 5 km wide.

The formations arose from calcareous deposits from a warm, Devonian sea at a not too great depth. By flushing in magnesium-rich water, the carbonate of lime was replaced by carbonate of magnesium and the harder dolomite rock was created . Dolomitization occurs in the pseudomorphism , in which the more easily soluble carbonate of lime (CaCO 3 ) is leached and carbonate of magnesium (MgCO 3 ) is enriched. The rock becomes grainy and increasingly porous to rough. As a result, fossils lose their clear shapes and are increasingly difficult to identify or are even destroyed. In some places the rock was mined industrially, for example in the Pelm lime works .

In the area of ​​the Gerolsteiner and Hillesheimer Kalkmulde , the strip of the western Vulkaneifel that runs from northwest to southeast, roughly from Ormont to Bad Bertrich , crosses the Kalkeifel. Here there is not only a concentration of tertiary stratovolcanoes (approx. 43 million years old to approx. 25 million years old), but also remnants of the much younger Quaternary volcanism (age approx. 570,000 years to approx. 8,400 years ago) Years). Volcanism pierced the Devonian strata. Many minerals of interest to mineralogists and collectors were formed on the contact surfaces of calcareous Devonian detritus and volcanic materials .

Geesops sparsinodosus gallicus - trilobite named after Gees

Since the beginning of the 20th century at the latest, the Gerolsteiner Mulde has been a well-known find area for z. Sometimes spectacularly well-preserved fossils from the Givetium , i.e. the Middle Devonian, especially crinoids . One of the world's most famous fossil sites is also located in the hollow, the trilobite fields near Gees , on the old road to Salm . The approximately 17 hectares of trilobite fields have been a designated nature reserve since 1984 and collecting fossils is prohibited there. Trilobite shells found in the marl limestone there are partially so well preserved that their colors can be determined. The fields have been known since the beginning of the 19th century and were visited by Alexander von Humboldt , among others , who collected trilobites there so successfully that he supposedly had to buy their woolen socks from farmers' wives in order to be able to transport the harvest from his search.

Landscape image

Papenkaule at the intersection of the Kalk and Vulkaneifel

The Devonian formations around Gerolstein are partially overlaid by remains of the Quaternary volcanism in the Eifel. Such a formation also separates the Prüm Kalkmulde to the southwest from the Gerolsteiner Mulde. Immediately next to the Munterley is a volcanic explosion funnel, the Papenkaule . The lava did not emerge from the Papenkaule, but from a secondary crater, the Hagelskaule, and extends, overlying the Devonian formation, as a Sarresdorf lava flow down towards the Kyll, where the lava flow is broken through by the railway embankment.

Steffelner Drees (carbonated mineral spring) in the Vulkaneifel

Volcanic mountain forms dominate the horizon to the east. Traces of volcanism can be found in the frequently occurring carbonated mineral springs (dialectively Drees ), which are also used industrially, but are in some cases also openly accessible, for example off the highway 410 before Lissingen or near Gees.

literature

  • Johann Josef Baptist Dohm: The limestone basin of Gerolstein in the Eifel - An introduction to geology (=  Fischer's natural scientific home guide . Volume 2 ). G. Fischer, Wittlich 1930, DNB  579664171 .
  • Karl-Heinz Köppen: Geology and hydrogeology of the Gerolsteiner Mulde and its surroundings . Trier 1987, DNB  900283440 (dissertation).

Individual evidence

  1. ↑ a b Landscape profile 27603 Südliche Kalkeifel  ( 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. ; on the website of the Federal Ministry for Nature Conservation; Retrieved July 11, 2017.@1@ 2Template: Toter Link / www.bfn.de  
  2. ↑ Great Landscape Osteifel, 276.90 Gerolsteiner Kalkmulde
  3. ↑ Gerolsteiner Dolomites ; on www.eifelfuehrer.de; Retrieved July 11, 2017.
  4. ↑ a b c d e f Gerd Ostermann (1993) The Gerolsteiner Dolomites ; Heimatjahrbuch Vulkaneifel.
  5. ↑ a b Werner Pockrandt (1981) Das Unterdevon der Eifel ; Working Group Paleontology Hannover; 1981, issue 3.
  6. ↑ a b c d Hermann Rauff (1911) Draft for a geological guide through the Gerolsteiner Mulde; Distributed by the Royal Geological State Institute Berlin, No. 4, Invalidenstrasse 44.
  7. ↑ a b c d Wolfgang Rebske (1980) General volcanic excursion with an introduction to the external shape of the volcanoes, effusions, maar formation etc. of the tertiary and quaternary volcanism in Bolko Cruse; On the mineralogy and geology of the Koblenz area of ​​the Hunsrück and the Eastern Eifel ; The exposure; Special volume 30 (Koblenz); Heidelberg 1980; Published by the Association of Friends of Mineralogy and Geology (VFMG) eV Heidelberg. Pages 65 to 86.
  8. ↑ Joachim Hauser (2003) About Clistocrinus KIRK, 1937 from the Middle Devon (Givetium) of the Gerolsteiner Mulde (Germany, Eifel) ; accessed on July 24, 2017.
  9. ↑ Martin Meschede (2015) Geology of Germany: A process-oriented approach ; Springer-Verlag; ISBN 978-3-662-45298-1 ; Page 81/82.
  10. ↑ Entry on trilobite fields (Gees, Gerolstein municipality) in the database of cultural assets in the Trier region ; accessed on August 17, 2017.
  11. ↑ Detlef Wienecke-Janz et al. (Editor, 2008) The Great Chronicle World History: From the Big Bang to the first life forms: [from 13.7 billion to 292 million] ; Volume 1 of Great Chronicle World History; Wissenmedia Verlag, ISBN 978-3-577-09061-2 ; Page 290 ff.
  12. ↑ a b Gees on www.mineralienatlas.de; accessed on August 10, 2017.
  13. ^ Ordinance on the Trilobite Fields Nature Reserve near Gees ; of the Daun district of June 12, 1987.
  14. ↑ Brigitte Schoenemann, Euan. NK Clarkson and Uwe Ryck (2014) Color Patterns in Devonian Trilobites ; The Open Geology Journal, 2014, 8, 113-11.
  15. ↑ The rulers of the ancient world ; Frankfurter Allgemeine Sonntagszeitung from September 23, 2003.

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