Wilhelmine pit
| Wilhelmine pit | |||
|---|---|---|---|
| General information about the mine | |||
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| Mining technology | Underground mining , opencast mining before 1817 | ||
| Information about the mining company | |||
| Start of operation | 1542 | ||
| End of operation | 1923 | ||
| Funded raw materials | |||
| Degradation of | Copper ore | ||
| Geographical location | |||
| Coordinates | 50 ° 4 '8.8 " N , 9 ° 16' 19.1" E | ||
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| Location | Summer bald | ||
| local community | Summer bald | ||
| District ( NUTS3 ) | Aschaffenburg | ||
| country | Free State of Bavaria | ||
| Country | Germany | ||
In the eastern outskirts of Sommerkahl in the Bavarian Spessart located Grube Wilhelmine one of the rare in Bavaria was from the mid-16th century copper deposits mined mined .
history
The pit was first mentioned in 1542. At first, iron and copper-containing minerals were extracted in open-cast mining, with varying success. The Wilhelmine copper and fahler ore mine experienced an interrupted upswing from 1870 onwards under the merchant Justus Matthäus Bastert from Frankfurt am Main, who had switched to underground copper mining and who had the ore processed for smelting in a nearby leaching plant. His company, the Spessarter Kupfergruben- und Hüttenverein zur Justushütte near Aschaffenburg, melted the copper in the Justushütte zu Damm. The Justushütte was located on the Aschaff in the area of what is now the Mainaschaffer Straße 57 property, which at that time belonged to a flour and heavy spar mill (later also called rag mill). The relatively low copper content of the ore has repeatedly challenged profitability. From 1920 to 1922, more than 100 miners extracted around 70 tons of copper-bearing ore every day , from which, however, only about one ton of material that was ready for smelting could be extracted. In 1923 the company was finally closed due to a lack of profitability.
Origin of occurrences
The area around Sommerkahl consists of the Schöllkripper gneiss of the Variscan basement , which was formed around 335 million years ago during the Carboniferous period, when granite metamorphosed due to high temperatures and pressures and turned into muscovite - biotite- gneiss. In the Jura , when the gneiss was not yet on the surface, but was covered by sediments, crevices opened in the rock through which hot, sulphurous and silicic acid waters, so-called hydrothermal solutions , flowed. These solutions probably also penetrated the overlying sediments ( Rotliegend and / or copper shale ) and dissolved the copper minerals present in them. The copper got into the crevices in the gneiss with the solutions and was precipitated again there together with barite and quartz in the form of sulfidic copper ore minerals . Such filled crevices are called hydrothermal dikes . Mining was only worthwhile in the corridors in which large amounts of copper ore minerals had crystallized out due to the geological processes.
Discoloration of the rock
In the corridors of the Wilhelmine mine, copper is bound in the sulphidic minerals chalcopyrite , bornite and tennantite . Under the influence of water and carbon dioxide from the air, these primary ore minerals oxidize in a similar way to rusting iron . In the case of copper ores, however, colorful green malachite and blue azurite are formed as secondary minerals that crust over the rock. Unsuitable for mining, the colored copper carbonates, however, do a good job as so-called prospecting minerals in the detection of copper deposits on the earth's surface. The noticeable discoloration can also be seen on the steep face of the original opencast mine above the entrance tunnel.
Visitor mine
Not for copper extraction, but for historical and conservation reasons, the mine was privately restored and maintained and expanded as a visitor mine. In clearing operations backfilled tunnels are in the mine again minerals found are shown to visitors in an exhibition. The mine and exhibition can be viewed during a mine tour in summer after registration.
Bat roost
During the winter months, the tunnels and shafts of the Wilhelmine mine serve a large number of bats , including the great mouse-eared bats , to secure their quarters and thus to protect biotopes and species . Therefore the mine is not accessible during this time. The tunnels are then closed except for entry and exit slots. In the summer months, the nocturnal animals look for warmer places to sleep in the area.
Protection status
The in the mine and the open pit walls open-minded , crisscrossed by corridors gneiss is the Bavarian State Office for the Environment as a protected geological site reported.
See also
Individual evidence
- ↑ Bastert, Justus Matthäus, index entry: German biography , accessed on August 2, 2017.
- ↑ Bavarian State Office for the Environment: Wilhelmine E copper mine from Sommerkahl Geotope Register Bavaria, accessed on March 22, 2020
Web links
- Copper mine Grube Wilhelmine Sommerkahl 2000 e. V. - Website of the mine association
- Joachim Lorenz: The former copper mine of the Wilhelmine mine in Sommerkahl in the Spessart. - Richly illustrated portrait of the mine and its minerals on spessartit.de