Hydrothermal silver-bearing Pb-Zn mineralization in Moldanubian Pluton near Dačice and SlavoniceArticle PDF
Hydrothermal silver-bearing Pb-Zn mineralization in Moldanubian Pluton near Dačice and Slavonice
Small deposits of silver-bearing base-metal ores have been mined in the past along the eastern margin of Central Moldanubian Pluton, especially in the 16th century. However, their production was insignificant, and there was not much information about mining at that time. The source of the ore mineralization are quartz veins of NW-SE direction of Variscan age, deposited in Číměř type granite.
The mineral assemblage is simple, consisting of sulphides: galena, sphalerite, pyrite, arsenopyrite and chalcopyrite. In addition to galena, also chalcopyrite was a carrier of silver. Upon its supergene alteration, a mixture of covellite and acanthite was formed, native silver is rare. The maximum silver content in ore is around 2000 ppm and the gold content is ≤ 4 ppm. In the oxidation zone, abundant but very thin coatings and tiny aggregates of Fe-Cu-Pb-S-P supergene minerals (goethite, pyromorphite, corkite, malachite, native sulphur, destinezite) were formed in cavities and fissures in quartz.
Vladimír Hrazdil, Stanislav Houzar, Eva Víšková, Department of Mineralogy and Petrography, Moravian Museum, Zelný Trh 6, 659 37 Brno, e-mail: email@example.com