- a composite rock body containing two types of rock (esp igneous and metamorphic rock) that have interacted with each other but are nevertheless still distinguishable
C20: alteration of Swedish migmatit, from Greek migma mixture + -ite 1
- A rock of both metamorphic and igneous origin, that exhibits characteristics of both rock types. Migmatites probably form through the heating (but not melting) of rocks in the presence of abundant fluids.
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