Publication details
Hydrotermální karbonáty a termometrie žilné mineralizace v terciérních vulkanitech u Uherského Brodu
| Title in English | Hydrothermal carbonates and thermometry of vein mineralization in Tertiary volcanites near Uherský Brod |
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| Authors | |
| Year of publication | 2020 |
| Type | Article in Periodical |
| Magazine / Source | Geologické výzkumy na Moravě a ve Slezsku |
| MU Faculty or unit | |
| Citation | |
| Web | https://journals.muni.cz/gvms/article/view/13701/11711 |
| Doi | http://dx.doi.org/10.5817/GVMS2020-13701 |
| Keywords | Outer Western Carpathians; Tertiary volcanites; hydrothermal veins; carbonates; thermometry |
| Description | Hydrothermal mineralization in the Bučník quarry near Uherský Brod is the best locality for the study of this type of mineralization in the Outer Western Carpathians. The studied sulfide vein mineralization is genetically linked to Tertiary volcanics and represents a distance manifestation of the polymetallic vein type widespread in the metallogenetic region of the Central Slovakian Volcanic Field. Study of vein structure, ore textures and structures, chemical composition of carbonates, isotope thermometry (isotopic composition of sulfur in sphalerite/galena pairs) and fluid inclusions, including microthermometry, shows that mineralization occurred under complex and variable conditions. Carbonates, defined as calcites with a proportion of Fe and Mn, dolomites and Fe- and Mn-dolomites, Mg-ankerites, show a highly variable chemical composition clearly documented as fine zones in CL-microscopy and BSE images. Fluid inclusions contain the aqueous system H2O-NaCl and H2O-NaCl + MgCl2 + FeCl2-3. Fluid salinity ranges from 2.7 to 14.7 mass% NaCl eq. whereas it is higher for sphalerite than for carbonates. The same trend is for homogenization temperatures in the range of 121–272 °C. A sulfur isotopic geothermometry in combination with fluid inclusion microthermometry shows a relatively wide probable range of temperature conditions. The younger carbonate mineralization may begin at temperatures of 125 °C and around 210 °C may overlap with a temperature of sulfide association that ranges from 210 °C to 290, resp. 335 °C. Isotopic thermometry also suggests higher temperatures up to 450 °C and above, but these highest temperatures are rather unlikely and most likely correspond to isotopic disequilibrium. The wide temperature range in which the mineralization originated is in accordance with the development of the hydrothermal system in a very dynamic environment in terms of tectonic, magmatic and hydrothermal. The studied hydrothermal system has a number of physico-chemical parameters similar to polymetallic vein systems in the Central Slovakian volcanics region and Baia Mare district, Rumania, as well. |