Spinel in garnet peridotite occurring in the Bohemian Massif, Czech Republic, and pressure-temperature path

Abstract

Spinel was newly found from Nové Dvory garnet peridotite body in the Bohemian Massif, Czech Republic. In the spinel-bearing samples, oval or round spinel grains occur as inclusions within garnet and kelyphite. The spinel stable pressures were estimated using a reaction of pyrope + forsterite = spinel + 2 enstatite, and the calculated spinel stable pressures are lower than 3.0 GPa. Then, thermobarometers were utilized and gave the peak P-T conditions from ≈ 800°C, 3.0 GPa to 1000°C, 4.5 GPa. These observation and calculated results suggest that subduction of this peridotite body should have occurred prior to the peak-P metamorphism.