Question

what type of change occurs when metamorphic rock is transformed by heat

Answer 1

Metamorphic rocks form from heat and pressure changing the original or parent rock into a completely ... The word "metamorphic" comes from Greek and means "To Change Form".

Answer 2

Metamorphic Rocks are rocks that have changed form due to heat and pressure. Metamorphic comes from the Greek words meta and morph. Meta means change and morph means form. So we get metamorphic meaning to change form.

Metamorphic rocks were once sedimentary, igneous or even other metamorphic rocks that have been changed by heat and pressure.
For metamorphism to occur energy is needed to fuel the chemical reactions. Heat is the primary source of this energy.