Metamorphic rock

Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means ``change in form''. The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (100 megapascals (1,000 bar) or more), causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock.

Question: can a metamorphic rock become another metamorphic rock
Answer: yes