Because it is the result of the transformation of an existing rock type, the protolith, in a process called metamorphism. The protolith is subjected to heat and pressure causing profound physical and chemical change. The protolith may be sedimentary rock, igneous rock, or another (older) metamorphic rock.
Answers & Comments
Answer:
Metamorphic rock
Explanation:
Because it is the result of the transformation of an existing rock type, the protolith, in a process called metamorphism. The protolith is subjected to heat and pressure causing profound physical and chemical change. The protolith may be sedimentary rock, igneous rock, or another (older) metamorphic rock.