Hf isotopes and trace elements as indicators of zircon genesis in the evolution of the alkaline-carbonatite magmatic system (Il’meno-Vishnevogorskii Complex, Urals, Russia)

Abstract

384 The methods of local analysis in the study of the isotope composition and isomorphic admixture in zir� con stimulated treatment of this mineral as a widely applied instrument for rock dating, as well as for origin of substance sources and geochemical evolution of rocks. The geochemical data (the concentration and trace and rareearth elemen t patterns in zircon), as well as the study of the U-Th-Pb and Lu-Hf isotope systems, currently may be applied for these in addition to the morphology and cathode luminescent proper� ties of zircon. Using laser ablation (LA-ICP-MS), we studied the Hf isotope composition in combination with the U-Pb age and trace elements content in zircons of the Il'meno-Vishnevogorskii alkaline-carbonatite com� plex (Uralian foldbelt, Russia). The Il'meno-Vishnevogorskii Complex (IVC) composed of nepheline syenite (miaskite), fenite, miaskitic pegmatite, and carbonatite with REE-Zr- Nb mineralization is located in the South Urals, in the axial part of the Sysertsko-Il'menogorskii anticlino� rium and includes two large miaskite massifs (Vish�