The Mežica Pb-Zn mine in N Slovenia is one of the largest Pb-Zn deposits in the Alpine metallogenetic province, consisting of low-temperature epigenetic hydrothermal orebodies hosted in the rocks of the Wetterstein Formation. The predominant sulfide minerals are sphalerite, galena, and marcasite, while pyrite occurs in trace amounts. Sphalerite from the Mežica deposit has been recognised as an important carrier of several trace elements, which have been applied to estimate precipitation temperatures and to investigate the effects of subsequent hydrothermal processes on the primary ore.
In the scope of this thesis, petrographic observations, X-ray powder diffraction, scanning electron microscopy, and in-situ laser ablation with inductively coupled plasma mass spectrometry were carried out on sphalerite from the Mežica deposit.
Sphalerite from the Mežica deposit contains detectable amounts of Mn, Fe, Co, Ni, Cu, Ga, Ge, As, Se, Ag, Cd, In, Sn, Sb, Hg, Tl, and Pb. Dark brown and brown sphalerite types characteristically show elevated concentrations of Mn, Fe, Ge, As, Tl, and Pb compared to lighter varieties, enriched in Cd and Cu. Correlation trends between trace elements show direct and coupled substitution mechanisms such as M2+ ⒔ Zn2+ (M = Mn, Fe, Cd) and (Ag, Cu)+ + Ga3+ ⒔ 2Zn2+, respectively. Precipitation temperatures were calculated using the GGIMFis geothermometer, which yielded average temperatures of 120 ± 23 °C, indicating the low-temperature hydrothermal origin.
Based on petrographic observations combined with spectrometric analyses, it can be inferred that the initial paragenetic sequence of sulfides was subjected to a series of hydrothermal events that resulted in selective mobilisation and re-precipitation of minerals in multistage reactivated veins.
The dataset generated has important applications in the mineral exploration industry, providing a solid basis for ore deposit and tailings reassessment and providing comprehensive data on a deposit-level budget of critical elements.