page_title: Wismut (mining company)
section_title: Schneeberg-Schlema-Alberoda (Objects 02/03/09; mining division Aue)
hierarchical_section_title: Wismut (mining company) / Mining / Ore Mountains and Vogtland / Schneeberg-Schlema-Alberoda (Objects 02/03/09; mining division Aue)
caption_attribution_description: English: "Roter Kamm" fault in Bad Schlema, Germany: The quartz-hematite mineralised Roter Kamm fault is the central element of the Gera-Jachymov fault zone hosting the largest uranium deposits of central Europe. The vertical displacement in Bad Schlema is 400m with Variscan granites on the left and phyllites on the right. The fault is the boundary between the Schneeberg Ag-Co-Ni-U and Schlema-Alberoda U deposits. Deutsch: Aufgeschlossener Ausbiss des Roten Kammes, eines hydrothermalen Quarz-Hämatitganges, der ein zentrales Element der variszisch angelegten Gera-Jáchymov-Störungszone ist, bei Bad Schlema, Erzgebirge, Sachsen.
context_page_description: SAG/SDAG Wismut was a uranium mining company in East Germany during the time of the cold war. It produced a total of 230,400 tonnes of uranium between 1947 and 1990 and made East Germany the fourth largest producer of uranium ore in the world at the time. It was the largest single producer of uranium ore in the entire sphere of control of the USSR. In 1991 after German reunification it was transformed into the Wismut GmbH company, owned by the Federal Republic of Germany, which is now responsible for the restoration and environmental cleanup of the former mining and milling areas. The head office of SDAG Wismut / Wismut GmbH is in Chemnitz-Siegmar.
context_section_description: This ore field was the largest deposit in the Ore Mountains. It is situated about 20 km south of Zwickau in the western Ore Mountains. Schneeberg was an important mining center since the 15th century, producing silver, cobalt, nickel and bismuth, and the town of Oberschlema was known for its strongest naturally occurring radioactive waters at the beginning of the 20th century. A radium health center was established in the town in 1914.
  After the Second World War, Soviet scientists started exploring the old mining areas for uranium, and mining commenced in 1946 even before SAG Wismut was established in 1947. Schneeberg at the southern end of the deposit became Object 03 and Oberschlema Object 02. Subsequently the blind (no mineralisation reaches the surface) northern part of the ore field (Niederschlema-Alberoda) was discovered and mining started there in 1949. Object 09 was established to mine the Niederschlema-Alberoda part of the ore field.
  Mining in Schneeberg continued until 1954 reusing many shafts from previous silver and cobalt mining. Up to that time, about 200 tonnes of uranium was extracted from Schneeberg. Oberschlema was mined to depths of over 700 m. Mining ceased in 1960 after producing more than 7,000 tonnes of uranium. A high density of veins near the surface and the 'wild' mining methods of the 1940s and 1950s caused the complete destruction  of Oberschlema. Most houses were so badly damaged and the subsurface so unstable that the entire small town was removed in the 1950s. Today the former mining area hosts a radon health center reestablished in the 1990s. After a restructure of the company in the 1960s, Object 09 became Bergbaubetrieb Aue (mining division Aue). It developed into the single largest producer of uranium within SAG/SDAG Wismut with a peak production of 4,000 tonnes of uranium in 1965. In the last normal production year, 1989, it produced about 550 tonnes. This deposit was the first of all Wismut deposits to be supplied with large modern mining shafts and powerful ventilation in the mid-1950s . The most important shafts where Shaft 38 (Niederschlema), Shaft 366 (Aue-Alberoda) and Shaft 371 (Hartenstein). The latter went into production in 1959 and was the main shaft of the deposit up to the end of production in 1990. Shaft 371 possessed an automated sorting plant used to separate different classes of ore and to increase the overall ore grade. High grade ore was sent directly to the Soviet Union without further processing, while ore containing less than 1% uranium was shipped to the mill at Crossen near Zwickau. This was done until 1980; afterwards all ore was milled, with the sorting plant raising the average ore grade to 0.4% before it was sent to Crossen for processing. An unsuccessful attempt was also made to produce base metals, silver and selenium as by-products. Shaft 371 was connected to the -540 and -990 m level (the depth is related to the Markus Semmler adit dewatering the upper part of the deposit into the Zwickauer Mulde river). Deeper levels were connected by blind shafts. The deepest level opened in 1988 was the -1800 m level, nearly 2,000 m underground, making the mine the deepest in Europe. The mining method used was the same as in the centuries before, although with more modern equipment: galleries were driven along strike of the mineralised vein on a lower and upper level (vertical distance 30 to 45 m). These were connected by small shafts from the lower to the upper level. Then the vein was mined upward using drilling and blasting. The ore was transported to the lower level and brought to the main shafts by rail cars, while the stope was filled with waste rock, as possible. After a vein was mined out, the entrances were sealed to prevent radon from the old stopes from entering areas with active mining. This method was used in all vein type deposits of the Ore Mountains. The total production from Niederschlema-Alberoda was over 72,000 tonnes of uranium.  Together with the production from Schneeberg and Oberschlema, production losses and unmined resources, the total uranium
caption: Roter Kamm fault in Bad Schlema: The hematite-quartz mineralised fault is the geological boundary between the Schneeberg and Schlema-Alberoda deposits.
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