Geokemične značilnosti sfalerita iz rudišča Ledina : diplomsko delo

Ribič, Katarina (author), Šoster, Aleš (mentor), Rogan Šmuc, Nastja (member of the commission for defense), Dolenec, Matej (member of the commission for defense)

V diplomskem delu se osredotočamo na analizo vsebnosti in porazdelitve slednih elementov v sfaleritu iz rudišča Ledina. Cilj predloženega dela je bil določiti vsebnost slednih elementov v sfaleritu in na podlagi geokemičnih kazalcev določiti fizikalno kemične pogoje mineralizacije ter postaviti genetski model nastanka rudišča Ledina. Podatki o vsebnostih slednih elementov so bili pridobljeni in-situ z uporabo metode induktivno sklopljene plazme masne spektroskopije z vzorčenjem z lasersko ablacijo (LA-ICP-MS). Sfalerit iz rudišča Ledina smo na podlagi različnega stila mineralizacije in vsebnosti slednih elementov razdelili na tri glavne tipe: tip A, tip B in tip C. Sfalerita tipa B in C, sta se izločila v zgodnji (primarni) fazi mineralizacije ter sta zapolnjevala prazne prostore in nadomeščala karbonatno prikamnino. Obogatena sta s Fe, Cd, Pb, Hg in As, pri čemer tip B izstopa po povišanih vsebnostih Hg in Sb, tip C pa po izrazito visoki vsebnosti Cu. Sfalerit tipa A se je izločil v sekundarni fazi mineralizacije v obliki žil in je obogaten s Cd, Fe in Hg. Korelacije med pari Fe-Ge, Fe-As, Cu-Ga, Cu-Ge, Cu-Ag, As-Pb in As-Tl in razpršenost podatkov okoli regresijskih premic nakazujejo na sočasno delovanje več različnih mehanizmov vgradnje slednih elementov v sfalerit. Izsledki kažejo, da je orudenje potekalo pri povprečni temperaturi okoli 149 °C, ocenjeni z geotermometrom GGIMFis, medtem ko izotopska sestava sulfidnega žvepla galenita iz genetsko primerljivega sosednjega rudišča Bohor (δ34Sgal ≈ +5 ‰) podpira interpretacijo, da je redukcija sulfata potekala s termokemično redukcijo sulfata (TSR). Vsebnosti slednih elementov v sfaleritu in teksturne značilnosti minerala rudišče Ledina umeščajo v rudišča tipa Mississippi Valley (MVT).

• Language: Slovenian
• Keywords: Sfalerit, sledni elementi, geokemija, rudišča Ledina, MVT
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: K. Ribič
• Year: 2026
• Number of pages: XI, 37 f.
• PID: 20.500.12556/RUL-188583
• UDC: 55
• COBISS.SI-ID: 301068291
• Publication date in RUL: 24.09.2026

Secondary language

• Language: English
• Title: Geochemical characteristics of sphalerite from the Ledina mine : diploma work

Abstract

This diploma thesis focuses on the analysis of the concentration and distribution of trace elements in sphalerite from the Ledina ore deposit. The objective of the study is to determine the trace element content of sphalerite and, based on geochemical indicators, to infer the physicochemical conditions of mineralization and to establish a genetic model of the Ledina ore deposit. Trace element concentration data were obtained in-situ using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Based on the type of mineralization and trace element content, sphalerite from the Ledina ore deposit was classified into three main types: sphalerite type A, type B and type C. Sphalerite types B and C formed during early (primary) mineralization, both as an open space infills and as replacements of the host rock. These types are enriched in Fe, Cd, Pb, Hg and As, with type B characterized by elevated concentrations of Hg and Sb, and type C by significantly high concentrations of Cu. Sphalerite type A formed during later (secondary) mineralization, occurring as veins, and exhibits elevated concentrations of Cd, Fe and Hg. Correlations among Fe Ge, Fe-As, Cu-Ga, Cu-Ge, Cu-Ag, As-Pb and As-Tl, along with data dispersion around regression lines, suggests that multiple mechanisms incorporate trace elements into the sphalerite simultaneously. The results indicate that ore deposition occurred at an average formation temperature of approximately 149 °C, calculated using the GGIMFis geothermometer, while δ34S values of galena from the genetically related neighboring Bohor ore deposit (δ34Sgal ≈ +5 ‰) support reduction of sulfate via thermochemical sulfate reduction (TSR). The trace-element composition and the textural characteristics of the sphalerite from the Ledina ore deposit are consistent with a Mississippi Valley type (MVT) ore deposit.

• Keywords: Sphalerite, trace elements, geochemistry, Ledina deposit, MVT