What does "metamorphic" mean?

Metamorphic: Causing a change of structure.

Additional senses

  1. 2.(Geol.) Pertaining to, produced by, or exhibiting, certain changes which minerals or rocks may have undergone since their original deposition; -- especially applied to the recrystallization which sedimentary rocks have undergone through the influence of heat and pressure, after which they are called metamorphic rocks.

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