Dogger ore

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Dogger ores are iron ores of the southern German layer level country and the north-eastern Swiss Jura , which were formed in the brown Jura by deposition. Similar to the similarly old Lorraine minette or parts of the Cretaceous iron ore in northern Germany, it was deposited in the sea (submarine) off the coast in the form of so-called ooids (iron oolite ).

Emergence

The Süddeutsche Jura pool was the beginning of the Jurassic to the southwest and west with the Paris basin connected and north over the Hessian Road with the North German Jurassic sea. In the north-west of the southern German Jura basin there were long coastlines around the Ardennes - Rhenish island - the place where the Minette in Lorraine was formed - and in the east and south lay the banks of the Vindelizian threshold and the Bohemian massif , in front of which the Dogger ores formed.

Brown and red-brown, fine-grained sandstones were deposited over the Opalinus Clay from the coasts of the Vindelizi Sill and the Bohemian Massif, in which several ironoolite seams were formed. After their formation in the shallow water, the ooids were carried into the sea by currents, where they formed collections of sometimes considerable dimensions. The ores of the Murchisonaeoolith Formation ( Upper Rhine Graben ) and the Iron Sandstone Formation ( Franconian and Swabian Jura ) were of particular economic importance for southern Germany . In the further course of the Middle Jurassic there are other iron-o-olite inclusions that were only of local importance for iron ore extraction.

Occurrence

Fragments from the ferrous lower seam of the iron sandstone

Germany

Baden-Württemberg

The deposit at Blumberg in the Urdonautal , near the Swiss border, is an iron seam with a thickness of around 4 meters , the iron content is around 20%. The ore has a silica content of 23%. The ore deposits have been mined by Gutehoffnungshütte in Gutmadingen since 1931 and by Doggererz-Bergbau GmbH or its legal successor Doggererz AG in Blumberg since 1934. However, mining turned out to be uneconomical. At Wasseralfingen near Aalen , on the northern edge of the Swabian Alb, two seams have been formed, the total thickness of which is also around 4 meters. The iron content is between 21 and 42%.

Another deposit is located on the edge of the Upper Rhine Plain in the foothills of the Black Forest between Lörrach in the south and Lahr in the north. In Rietheim-Weilheim near the Maria-Hilf chapel, Doggererz was mined for the blast furnaces in Ludwigsthal until 1861 . Women and children were not allowed to enter the 3.5 km long tunnel. Ores were also transported from the Zollernalb district to the iron and steel works in Tuttlingen . The nearby smelter in Harras was shut down in 1832. After the construction of high-performance railway lines, iron ore was mined in southern Germany in order to use a ferrous aggregate over the limestone that was always required in the blast furnace. The gold cave is an approximately 180 year old collapsed tunnel in Geislingen (Zollernalbkreis) . During the new construction of the Stuttgart – Ulm railway line in Geislingen an der Steige , an iron ore seam was exposed, which was opened up with a tunnel until 1963.

Bavaria

In Pegnitz in Franconia there were two mining areas: one on Zipser Berg ( civil engineering ) and Long Reuth ( open pit ). The iron content is 28 to 37%.

Switzerland

At Wölflinswil - Herznach - Ueken in the Fricktal region , Dogger ores have been mined to a thickness between 3 and 7 meters and an iron content of around 50% since the Middle Ages.

Extraction

Attempts to use Dogger's ore for iron extraction date back to the 16th century, but it was only with the Paschke-Peetz process in 1934 that it could be economically smelted into iron. As part of the self-sufficiency efforts in the Nazi era, the mining of Dogger ore was accelerated and the Doggererz AG was founded for this purpose. Investigations of the slag from historical iron smelting in the Swabian Alb area show a new type of small smelting furnace that has also been able to smelt Doggereze since the 13th century.

Individual evidence

  1. ^ History of Blumberg. Retrieved May 25, 2010 .
  2. ↑ mineralienatlas.de: Wasseralfingen. Retrieved June 26, 2014 .
  3. ^ Wilfried Huber: Iron ore in the Black Forest. Röchling and the Dogger ore mining in Blumberg. (= Series of publications by the Initiative Völklinger Hütte eV , Volume 2), Völklingen 2004, p. 2.
  4. ↑ Volker Amann: Festschrift 800 years Geislingen .
  5. ↑ Emminger: Yearbook 1839 . S. 352 .
  6. ^ Eisenweg / Geology and ore mining. (No longer available online.) Archived from the original on March 4, 2016 ; Retrieved May 25, 2010 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.verein-eisen-und-bergwerke.ch
  7. ^ Wilfried Huber: Iron ore in the Black Forest. Röchling and the Dogger ore mining in Blumberg. (= Series of publications by the Initiative Völklinger Hütte eV , Volume 2), Völklingen 2004, p. 4.
  8. ↑ : Rennofen . In: Reutlinger Generalanzeiger , May 22, 2007.
  9. ^ Martin Kemp: Medieval ironworks , Schwäbisch Gmünd.

literature

  • Günter M. Walcz: Doggererz in Blumberg - the unusual fate of a city: a chapter of German mining history Südkurier, Konstanz 1983, ISBN 3-87799-036-3 .
  • Rolf Bühler: Herznach mine - memories of the Fricktal ore mining. AT-Verlag, Aarau / Stuttgart 1986, ISBN 3-85502-266-6 .
  • H.Fehlmann: Swiss iron production, its history and economic importance. Bern 1932.