Garnet crystallization mechanisms and localized polymetamorphism in the southwestern Meguma Terrane, Nova Scotia, Canada

We present data on the pressure and temperature (P–T) conditions experienced by metamorphic rocks of the Meguma Terrane, Nova Scotia, Canada, also utilizing three‐dimensional microstructural data on one sample to better constrain the mechanisms that controlled garnet crystallization. Inverse and forward thermodynamic modelling place peak P–T conditions in the southwestern Meguma Terrane at ~650°C and 4.5 kbar. Interpretation of these results with petrographic observations and previous P–T constraints across the terrane suggests that amphibolite facies metamorphism occurred during the Devonian Neoacadian orogeny (406–388 Ma). Integration of quantitative 3D textural data with an estimated metamorphic heating rate of