Where does the melting occur that forms metamorphic rocks?

2 Answers

By melting.

Explanation:

After a sedimentary rock (an eroded igneous rock ) has suffered high levels of heat and pressure, a metamorphic rock is created.

If a metamorphic rock is not risen by geological movement

---------- such as tectonic movement which initiates orogeny

...from below the outer Earth's crust, it means it has stayed deep down so that, eventually, melts due to extremely high temperatures, making the rock cycle start again.

http://utahscience.oremjr.alpine.k12.ut.us/sciber02/elem/4th/rocks/html/cycle.htm

Jun 23, 2017

Melting occurs primarily in subduction zones.

Explanation:

Metamorphic rocks can get dragged down in subduction zones and melted into magma. However, over vast periods of geological time most metamorphic rocks have not been subducted and have become the vast Precambrian shield regions of the world.