Manganese distribution in metapelitic garnet
Garnet crystals in micaschists from Sierra Pie de Palo (Western Argentina) show a strong zonation in manganese developed during crystal growth. During metamorphism (approx. 420-460 Ma ago) the garnet experienced a stage of resorption, followed by a second growth stage. Mineral chemical composition in combination with the microstructure allows deducing the pressure-temperature conditions of rock metamorphism.
Recorded on CAMECA SXFiveFE at Ruhr-Universität, Bochum, Germany. Sample courtesy of A. Willner. Image courtesy of N. Jöns.