Differences in staurolite mode due to changes in bulk composition as an effect of mass transfer by fluids during metamorphism

Abstract: Results from petrographic analyses, chemical analyses and mineral phase diagram calculations show that staurolite minerals grew in selvages adjacent to quartz veins. Previous studies show the same relationships between quartz veins and garnet, as well as kyanite growth. The selvages are formed as metamorphic fluids flow through cracks, altering the bulk composition by mass transfer and triggers the nucleation and growth of new minerals. A pseudosection for a staurolite absent sample has been calculated using THERMOCALC. No stability field correlates to visually observed mineralogy. This indicates that a reaction forming staurolite never was triggered since no fluids was present during metamorphism.