Dating of skarn Ca-garnets

Dating of skarn Ca-garnets

Application of isotope-geochemical LA-ICP-MS and ID-TIMS methods

The combined application of isotope-geochemical LA-ICP-MS (Laser Ablation Inductively Coupled Mass Spectrometry) and ID-TIMS (Isotope-Dilution-Thermal Ionization Mass Spectrometry) techniques with field, microscopic and mineralogical research allowed for the first time in Bulgaria to date skarn Ca-garnets from different metallogenic zones. New U-Pb LA-ICP-MS garnet standards have been introduced, allowing more accurate age definitions. The geochemical features of garnets from the grossular-andradite series of different types of ore deposits or manifestations are derived and the place and significance of the studied skarns in the developed models of geochemical and geochronological evolution of magma-hydrothermal systems are determined. Conclusions are made about the connection of skarns with magmatic and metamorphic processes and their influence on the macro- and microelement composition of grenades from alkaline magmatic complexes from the Kola Peninsula, Russia is evaluated.