Hoppanová, Eva, 1995-

Hydrothermal quartz-baryte veins containing Pb-Cu-Sb-(Bi) mineralization at Brusno-Brzáčka occurrence (Veporic Unit, Central Slovakia) and their supergene alteration / Eva Hoppanová, Štefan Ferenc ... [et al.]. -- The Brusno-Brzáčka occurrence (N 48.7698772°; E 19.4128150°) is located near the Brusno village (Slovenské Rudohorie Mts. Veporic Unit). Historically, the mineralization was explored by small-scale mining works located at the contact between the siliciclastic rocks of the Upper Permian and the Lower Triassic age. Paleo-Alpine metamorphic-hydrothermal mineralization is represented by quartz, baryte, or quartz-baryte veins, containing weak ore mineralization. Its succession is as follows: coarse-grained quartz I, pyrite (mineralization period I); baryte (II); tetrahedrite-(Zn), chalcopyrite (III); galena (IV) and quartz II (V). Supergene alteration produced initially covellite and spionkopite in the cementation zone. The oldest minerals in the oxidation zone are goethite, pyromorphite and mimetite. They were succeeded by the crystallization of Ba-rich anglesite, which partly overlaps in time with the precipitation of slightly younger anglesite. The formation of baryte partly overlaps with the deposition of anglesite, but in most cases, it is clearly younger. Bismutite is the youngest supergene mineral. A solid solution of anglesite–baryte with a Ba content from 0.29 apfu up to 0.51 apfu (i.e., Ba-rich anglesite) was identified at the studied site. This mineral phase covers the field of immiscibility of the natural solid solution PbSO4 – BaSO4, but the Ba/Pb ratio practically does not enter the baryte field (Pb-rich baryte).

In Acta Geologica Slovaca. -- Bratislava : Univerzita Komenského v Bratislave, 2024. -- ISSN 1338-0044. -- ISSN 1338-5674. -- Roč. 16, č. 1 (2024), s. 1-17