Chovan M., Kubač A., Mikuš T., Žitňan P. & Prcúch J., 2019: Au-Ag tellurides and sulphosalts from epithermal Au-Ag-Pb-Zn-Cu deposit Banská Hodruša at the Rozália mine (Slovakia). Acta Geologica Slovaca, 11, 2, 43–62.

Au-Ag tellurides and sulphosalts from epithermal Au-Ag-Pb-Zn-Cu deposit Banská Hodruša at the Rozália mine (Slovakia)

Martin Chovan¹, Alexander Kubač², Tomáš Mikuš³, Peter Žitňan⁴ & Ján Prcúch⁵

¹Department of Mineralogy and Petrology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 542 15 Bratislava, Slovakia; chovan@fns.uniba.sk
²Department of Geology of Minerals Deposits, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 542 15 Bratislava, Slovakia
³Earth Science Institute of the Slovak Academy of Sciences, Ďumbierska 1, 974 01 Banská Bystrica, Slovakia
⁴Slovenské Kovy, Ltd., Kammerhofská 8, 969 01 Banská Štiavnica, Slovakia
⁵Slovenská Banská, Ltd., 966 61 Hodruša-Hámre 388, Slovakia

Abstract

The Au-Ag-Pb-Zn-Cu epithermal deposit Banská Hodruša of intermediate-sulphidation type is located in the middle Miocene Štiavnica Stratovolcano on the inner side of the Carpathian arc in Slovakia. There are two different styles of epithermal mineralization within the deposit. The earliest represents a subhorizontal multi-stage vein system (low-angle normal shear zone), while the much younger mineralization represents the extensive system of steep-dipping veins related to different tectono-geological events. Within the mineralization related to the shear zone the mineral Au-Ag-Te-S assemblage was determined, represented by zonal gold/electrum, hessite, petzite, Cu-cervelleite and Te-polybasite, all associate with galena. The altaite and unnamed AgPbTeS phase were found in hessite. Very rare zonal gold/electrum crystallized to quartz vugs, with Ag content ranging from 17.8 to 45.3 wt. %. Similar assemblage was determined in flotation concentrates from dressing plant, represented by Au-Ag tellurides calaverite-krennerite-sylvanite in association with hessite, Au-hessite, petzite, unnamed AgAuTeS phase, uytenbogaardtite, and petrovskaite. These minerals typically occur in form of aggregates or as thin rims around gold/electrum. The younger horst-related veins host Ag-(Bi, Cu, Sb, As)-S assemblage. The main mineral in this assemblage is polybasite-pearceite, the other minerals jalpaite, matildite, acanthite, schapbachite, cervelleite, and arcubisite are rare and typically associate with galena.Zonal aggregates of tetrahedrite-tennantite were found in association with base metal sulphides.

Key words: epithermal mineralization, tellurides, sulphosalts, gold, Rozália mine, Štiavnica stratovolcano, Western Carpathians

Manuscript received: 2019-07-08

Revised version accepted: 2019-10-28