Color Banding
in high-grade metamorphic rocks

Geology is a science full of transitions, and rock identification is no exception. This specimen is definitely metamorphic, but would you call it a GNEISS or a MIGMATITE? You would have to look carefully at the felsic layers. If they have completely melted and re-crystallized into an igneous rock, it's a MIGMATITE. If re-melting has not taken place, it's a GNEISS. From the photo, I doubt that this is a MIGMATITE, but either way, it clearly represents a metamorphic grade very close to the transition to magma formation and the creation of new igneous rock.



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