Crossing isomekes: elastic geothermobarometry of quartz and zircon in garnet from UHP rocks

Characterizing the pressure and temperature (PT) histories of eclogite-facies rocks is of key importance for unravelling subduction-zone processes at all scales. In this paper, Mattia Gilio and co-authors combine Zr-in-Rutile thermometry and thermodynamic modelling with micro-Raman measurements on quartz and zircon inclusions trapped in garnets to obtain pressures and temperatures of equilibration of a quartz-garnet vein from the Proterozoic Ulla gneiss basement and of garnet-kyanite gneiss from the Caledonian Blåho nappe, both in the Fjørtoft Ultra-High Pressure (UHP) terrane, Norway. Furthermore, they discuss about a new method do detect hydrostatic vs. non-hydrostatic stresses in the vicinity of quartz and zircon inclusions in garnet.