Gold from the quartz veins at the “Zelená jáma” locality, Zlaté Hory Ore District, Jeseníky Mts., Czech RepublicArticle PDF
Gold from the quartz veins at the “Zelená jáma” locality, Zlaté Hory Ore District, Jeseníky Mts., Czech Republic
The gold-bearing quartz veins are slightly discordant with respect to the foliation of host “quartzite schists” at the studied site “Zelená jáma“ (Zlaté Hory Ore District). Apart from quartz, the vein is formed by small amount of completely limonitized carbonate and fragments of host rocks. Chemical composition of gold corresponds mostly to electrum (62–72 at. % Au); sporadic diffuse domains are formed by gold-rich silver (12–20 at. % Au). Pyrite, galena (with elevated contents of Ag, Se, and Bi), rutile, and barite are accessories. The secondary phases are represented by goethite. Primary fluid inclusions hosted by gold-bearing quartz belong to two compositional types – CO2-H2O and H2O. Microthermometric parameters of both types of inclusions are characteristic for late-metamorphic fluids of the Zlaté Hory Ore District. The vein formed at pressures of 0.5–1.4 kbar and temperatures of ~215–250 °C. The mechanism of vein formation and P-T conditions are similar to other vein-type gold mineralizations occurring in the Vrbno Group. The mineral composition of veins, their textural features, as well as chemical compositions of ore minerals are consistent with a late-metamorphic (secretory?) origin of this mineralization.
Miroslav Nepejchal, Žižkova 8,787 01 Šumperk, Czech Republic, e-mail: firstname.lastname@example.org
Zdeněk Dolníček, Department of Geology, Palacký University, 17. listopadu 11,771 46 Olomouc, Czech Republic, e-mail: email@example.com
Bohuslav Fojt, Institute of Geological Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, e-mail: firstname.lastname@example.org
Kateřina Mičudová, Department of Geology, Palacký University, 17. listopadu 11, 771 46 Olomouc