The BiCoNi Formation is a hydrothermal lode formation, in which bismuth,

cobalt Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, pr ...

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

and

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

ores have coalesced. It occurs mainly in the Ore Mountains and is the youngest formation in the hydrothermal sequence (polymetalliferous (kb) formation, iron-barite (eba) formation, precious brownspar (eb) formation, fluorite-barite (fba) formation, BiCoNi formation). Due to its combination with uranium, it is occasionally also called the bismuth-cobalt-nickel-uranium formation.

Genesis

The BiCoNi Formation emerged during the contact metamorphic restructuring of sedimentary

slate Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. ...

in the course of

Variscan The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Variscan'', comes f ...

granite intrusions during the Subhercynian-Austrian (''Austrisch'') cycle about 100–80 million years ago. It is the product of an intracrustal, epithermal paragenesis. It runs in quartz lode types as the primary ores or cobalt and nickel, which usually occur together with arsenides,

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

bismuth and pitchblende.

Use

The BiCoNi Formation has been intensively mined since the

Late Middle Ages The Late Middle Ages or Late Medieval Period was the Periodization, period of European history lasting from AD 1300 to 1500. The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Eur ...

for bismuth, later cobalt and nickel, and, since the late 19th century, also for uranium. In the second half of the 20th century it was intensively mined by SDAG Wismut.

References

Literature

* * * *

External links

* * {{cite web, title=Die Arsenproblematik in Betrieben der ehemaligen SAG/SDAG Wismut, periodical=Kompass 5/6 2005, url=http://www.igf-bbg.de/adobe/1210.pdf, format=PDF, 174kB, accessdate=2014-02-26, last=H.-D. Bauer, G. Stoyke, date=2005, language=German Ore Mountains