Evolution and economic potential of the Mesoproterozoic highly-fractionated granites (supervisor dr. Laurynas Šiliauskas)
Rare metal granites (RMG) are chemically distinct type rocks, characterized by their enrichment in volatiles and fluxing elements (e.g., F, Li, and/or P, B), as well as disseminated mineralization of Li, Sn, Nb and Ta. Often RMGs are highly fractionated, scattered throughout large areas as pegmatitic and aplitic veins. The distribution of mineralization is strongly controlled by fractional crystallization, changes in physicochemical conditions, tectonic setting of emplacement and late-stage alterations.
Such granites of peraluminous affinity are found in the southern part of Lithuania, where they are temporally and spatially associated with the Mesoproterozoic AMCG complex. According to Linnen and Cuney (2005), these granites can be classified as peraluminous low phosphorus (PLP) granites. However, scarce research on these rocks has been performed thus far and their economic potential remains unknown.
This proposal aims to develop a comprehensive model for this granitic body emplacement and to ascertain its economic potential. The main task of this research is to assess the petrological and geochemical character of the granitic rocks and determine their distribution and physical conditions of emplacement (T, P, fO2 and fluid composition in terms of F/OH, Cl/OH ratios). For this, various igneous thermobarometers will be applied (Ti in zircon, Bt, Hbl, Ilm-Mag thermobarometers etc.) together with detailed chemical mineral analysis and whole rocks composition, employed as petrological indicators and mineralization proxies.
The candidates for this position should possess a good understanding of igneous petrology and mineral chemistry. Good English skills are mandatory.