Origin of fractionated rhyolite porphyries of the Shartym pluton (Balbuk area, South Urals) based on mineralogy, geochemistry and thermodynamic modeling
А.А. Samigullin, I.R. Rakhimov
UDK
| 552.111, 550.42 | https://doi.org//10.35597/2313-545X-2026-12-3-6 | PDF (ENG) |
Abstract
About autors
References
Abstract
The paper examines rocks of the Shartym pluton (South Urals), which were previously ascribed to phase II of the Balbuk complex. The peraluminous rhyolite porphyries of the pluton are composed of feldspars, quartz and mica and belong to high-K series. Based on key geochemical criteria, they are close to I-type granitoids due to their formation under anatexis of island arc rocks. The Al2O3, FeO, MgO, Na2O and K2O content indicate a heterogeneous source for felsic magma, which includes island arc metagraywackes, metapelites and mafic pelites/siltstones. This is inconsistent with earlier ideas of the multiphase nature of the single Balbuk complex, in which the rhyolite porphyries are later rocks relatively to monzonites. Geochemical analysis and thermodynamic modeling demonstrate that the rhyolite porphyries of the Shartym pluton are not differentiates (the late phase) of a single magma, which yielded the crystallization of monzonites of the Balbuk complex. The location of the compositions in the CHARAC (Charge- and Radius-Controlled) field and Zr/Hf ratio of zircon of >25 indicate moderate fractionation of the rhyolite melt.
Keywords. South Urals, Balbuk area, Shartym pluton, rhyolite porphyries, mineralogy, geochemistry, modelling, fractionation of felsic melts.
Funding. This work was supported by state contract of the Institute of Geology, Ufa Federal Research Center, Russian Academy of Sciences no. FMRS-2025-0015.
Acknowledgements. We acknowledge the memory of Delir Nurzadayevich Salikhov for his valuable consultations on geological and geochemical features of igneous rocks of the Balbuk area.
Conflict of interest. The authors declare that they have no conflicts of interest.
Authors contributions. Samigullin A.A. – sample collection, sample preparation, analysis, interpretation; Rakhimov I.R. – choice of the research object, discussion of results.
For citation: Samigullin А.А., Rakhimov I.R. Origin of fractionated rhyolite-porphyries of the Shartym pluton (Balbuk area, South Urals) based on mineralogy, geochemistry and thermodynamic modeling. Mineralogy, 2026, 12(3), 105–00. https://doi.org/10.35597/2313-545X-2026-12-3-6
Keywords. South Urals, Balbuk area, Shartym pluton, rhyolite porphyries, mineralogy, geochemistry, modelling, fractionation of felsic melts.
Funding. This work was supported by state contract of the Institute of Geology, Ufa Federal Research Center, Russian Academy of Sciences no. FMRS-2025-0015.
Acknowledgements. We acknowledge the memory of Delir Nurzadayevich Salikhov for his valuable consultations on geological and geochemical features of igneous rocks of the Balbuk area.
Conflict of interest. The authors declare that they have no conflicts of interest.
Authors contributions. Samigullin A.A. – sample collection, sample preparation, analysis, interpretation; Rakhimov I.R. – choice of the research object, discussion of results.
For citation: Samigullin А.А., Rakhimov I.R. Origin of fractionated rhyolite-porphyries of the Shartym pluton (Balbuk area, South Urals) based on mineralogy, geochemistry and thermodynamic modeling. Mineralogy, 2026, 12(3), 105–00. https://doi.org/10.35597/2313-545X-2026-12-3-6
Received 11.06.2026, revised 27.06.2026, accepted 08.09.2026
About autors
Aidar A. Samigullin – Post-Graduate Student, Junior Researcher, Institute of Geology UFRC RAS, Ufa, Russia; samigullinaidar85@gmail.com.
Ildar R. Rakhimov – Cand. Sci. (Geol.-Mineral.), Senior Researcher, Institute of Geology UFRC RAS, Ufa, Russia; rigel92@mail.ru.
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