Calcic amphibole thermobarometry in metamorphic and igneous rocks: New calibrations based on plagioclase/amphibole Al-Si partitioning and amphibole/liquid Mg partitioning

The calibrated expressions yield P-T estimates consistent with those obtained with widely used barometers and thermometers. Plagioclase-amphibole barometry extends pressure determinations to quartz-free and/or garnet-free assemblages.