Major Textures of Metamorphic Rocks Under the Microscope
Granoblastic polygonal texture (triple jucntions) in granulite
Acicular texture (actinolite schist)
Decussate texture (mica schist) interlocking platy crystals of muscovite
Porphyroblast in phyllite
Mylonitic texture
Porphyroblasts with ribbon texture
Relationships between internal and external schistosity
(a) and (b) post-tectonic porphroblast (parallel internal and external schistosity)
(c) and (d) Pretectonic porphyroblast. notice pressure shadow in (c)
(e) and (f)Syntectonic porphyroblasts. Notice snowball garnet in (c)
Syntectonic (snowball) porphyroblasts in schist
