Photomicrographs (plane polarized light). (a) Sample GDB8. Main penetrative foliation S₂ (fine-grained biotite + prismatic sillimanite) wraps around (a) a microlithon with preserved foliation S₁ marked by coarse-grained biotite and prismatic sillimanite, and anhedral porphyroblasts of garnet with abundant inclusions of fine sillimanite needles. The dashed line A-B indicates the location of the chemical profile of garnet (Fig. 7a). Sample SP3B: (b) String of monazite crystals aligned parallel to the foliation S₂ marked by biotite, which also crystallizes in the fractures and at the rims of garnet porphyroblasts containing inclusions of monazite. A-B indicates the location of the chemical profile of garnet (Fig. 7b). Sample SAN: (c) Biotite and rare fibrous sillimanite mark the main foliation (S₂) and (d) andalusite replaced partly by chlorite. Sample MAD1A: (e) Foliation S₂ marked by biotite and clusters of fibrous sillimanite. (f) Garnet porphyroblast in contact with rare staurolite crystals. The dashed line A-B indicates the location of the chemical profile (Fig. 7c). Sample KOU7: (g) Staurolite contains quartz inclusion trails that mark the foliation S₁, oblique to the matrix foliation S₂. (h) A-B – Location of the chemical profile (Fig. 7d) across a garnet porphyroblast with inclusions of ilmenite and quartz.