1. Metamorphic Rock: This rock has already been transformed from existing sedimentary or igneous rocks by intense heat and pressure. It's changed at a molecular level but remains solid.
2. Melting: The metamorphic rock needs to be exposed to even more heat, reaching its melting point. This often occurs deep within the Earth's crust or in areas of volcanic activity.
3. Magma Formation: When the metamorphic rock melts, it becomes molten rock called magma.
4. Cooling and Crystallization: The magma, either inside the Earth or erupted as lava onto the surface, starts to cool. As it cools, minerals crystallize and solidify, forming new igneous rocks.
Therefore, the main process involved in turning metamorphic rock into igneous rock is melting, followed by cooling and crystallization. This process is known as the rock cycle.
