Ag-Co-Bi-U-Deposit Potůčky (Breitenbach) in Krušné hory Mts. (Erzgebirge Mts.), Czech Republic

Aleš Bufka – Ministry of Industry and Trade of the Czech Republic, Prague, Czech Republic
Dalibor Velebil – National Museum, Prague, Czech Republic
Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha) 8 (2000), 75–81


The historical mining district of Potucky is located in Krusne hory Mts., 15 km NW of Jachymov, on the Czech-German border. During the 16th to 20th centuries, so called "Jachymov five-elements type of veins" were exploited in Potucky. That means that silver, cobalt, bismut and uranium were successively mined there. The hydrothermal ore veins in Potucky are developed within the metamorphosed mantle of so called Karlovy Vary plutonic massive formed by different types of phyllites. There are about 20 ore veins known of the thickness generally in the range of 5–30 cm with brecciaed and mylonite filling and with lens-shaped bodies of quartz. The accumulation of complex of Co – Ni – Bi ores (skutterudite, safflorite, rammelsbergite, niccolite, bismut) appears in these quartz bodies. During the development of the deposit, about five mineralization stages of Variscian age successively applied as follows: 1. quartz-sulphide, 2. uraninite-carbonate (with fluorite), 3. arsenide, 4. sulphoarsenide, 5. sulphide (arsenopyrite, chalcopyrite, pyrite, galenite, sphalerite). Relatively separated is a younger quartz-hematite mineralization. All types of the ore mineralizations overlap each other, constitution of veins is variable, the vertical zonality of the deposit is also evident: uranium ores appear in the middle and deep parts of veins, silver and sulphoarsenid ores in the top and middle parts of deep development of the deposit. During the 18th a 19th centuries, hundreds kg of silver, 141 tons of cobalt ores and 2243 kg of bismute were mined out from this deposit. Amount of exploited uranium is not known; after the Second World War (1946–1956), about 60 km of mine galleries, with maximal depth of more than a 300 meters was driven. Now, the mining district is being liquidated, only residues of dumps remains by old pits.

Keywords: history, geology, uranium ores