Index Geophysics

Geochemical characteristics of mercurian tetrahedrite, barite and fluorite from the Duboki Vagan, Glumac and Dubrave-Dugi Dol barite deposits, south of Kreševo, Mid-Bosnian Schist Mts.

<p>The geochemical characteristics of tetrahedrite and barite of the Duboki Vagan barite deposit near the town of Kre&scaron;evo in the MBSM (Mid-Bosnian Schist Mountains) have been determinated and correlated with the results of previously studied barite, from the adjacent Glumac deposit, and fl uorite, from the Dubrave-Dugi Dol barite deposits. The studied tetrahedrite is characterized by a high content of Au (39 ppm) and Ag (&gt;300 ppm), the presence of Co (63.5 ppm), Ni (266.2 ppm) and Cd (313,6 ppm) in the crystal lattice and negative &delta;34SCDT values (&ndash;11.80&permil;). On the plot of its C1 chondrite-normalized REE abundances, a slightly expressed positive Eu anomaly and high HREE concentrations are observed. The high content of SrSO4 (2.33 to 3.42 wt.%) in the barite crystal lattice indicates hydrothermal parent solutions. The &delta;34SCDT values of the studied barite are +10.40&permil;, which is typical for Permian seawater and its &delta;18OSMOW values range between 15.6 and 17.7&permil;. A distinct positive Eu anomaly is shown on the plot of the C1 chondrite-normalized REE abundances in barite. Geochemical characteristics of the studied tetrahedrite and barite of Duboki Vagan are very similar to those of previously investigated Glumac and Dubrave-Dugi Dol barite deposits. The fluorite from the Dubrave-Dugi Dol deposits displays a negative Eu anomaly and its Tb/La and Tb/Ca ratios indicate a quite different origin in relation to barite formation. This is all in the accordance with the possible existence of two different paragenetic types of barite deposits in the MBSM and SEB (Southeastern Bosnia), which significantly differ in the &delta;18OSMOW ranges of their barites and &delta;34SCDT values of their sulphides. The first type of barite deposits originated in the Late Variscan phase (Lower Permian). It is characterized by numerous Cu, Fe, Zn, Sb, As, Pb sulphides and Cu-Sb-tetrahedrite without mercury, all having positive &delta;34SCDT values (0 to +5 &permil;). Early intercontinental rifting took place between the uppermost Permian and Lower Triassic and enabled, in a great number of barite deposits, (especially in the MBSM), remobilization and partial fluidization of their Fe, Cu, Zn, Sb and Pb sulphides which reacted with ascended mercury, sulphur and fluorine rich mantle fluids and resulted in the formation of Hgtetrahedrite and octahedral fluorite. These processes caused the occurrence of the second paragenetic type of barite deposit with Hg-tetrahedrite as the main ore mineral, but characterized by strongly negative &delta;34SCDT values.</p>

Ivan B. Jurković

Vesnica Garašić

Ivan Jurković

Paleozoic, Mid-Bosnia, Hg-tetrahedrite, barite, fluorite, stable isotopes (S, C and O), trace elements, REE, genesis

Geology

QE1-996.5

Croatian Geological Survey

2011-02-01T00:00:00Z

article

1330-030X

1333-4875

10.4154/GC.2011.05

https://doaj.org/article/bc01d2f4e3364fcd90f457be8dd389e1

Geologia Croatica, Vol 64, Iss 1, Pp 49-59 (2011)

EN

http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/482

https://doaj.org/toc/1330-030X

https://doaj.org/toc/1333-4875

Journal Licence: CC BY