Fig. 5
Mg/(Mg+Fe2+) versus Si (afu atoms per formula unit) amphibole classification diagram (after Leake et al. 1997). All samples have (Na+K)A < 0.50 and Ti < 0.50. Only the relevant part of the actinolite field (Mg/(Mg+Fe2+) > 0.8 is reported. The inset illustrates the compositional variation of amphibole from the reaction front to the core, across two representative thin sections ca. 40 mm large