Page 238 - Microtectonics

228 7 · Porphyroblasts and Reaction Rims

Fig. 7.55. Corona of garnet (black) separating plagioclase (centre) from clinopyroxene and hornblende in the matrix. Such monominer-
alic coronas are also known as moats. Retrograde granulite. Southern Minas Gerais, Brazil. Width of view 2 mm. PPL

Fig. 7.56. Reaction rim composed mainly of muscovite around a staurolite crystal in staurolite biotite schist. The reaction rim forms a
pseudomorph after staurolite. Pyrenees, Spain. Width of view 16 mm. CPL