The process by which igneous and metamorphic rocks are buried and undergo tremendous heating and stress, transforming one rock type into another, is called metamorphism. Metamorphism involves changes in the mineral composition and texture of the original rock (called the protolith) due to high temperature, high pressure, and sometimes chemically reactive fluids, without the rock melting. This process occurs deep within the Earth's crust and can affect igneous, sedimentary, or existing metamorphic rocks

. There are different types of metamorphism depending on the dominant factors and geological settings:

• Contact metamorphism : caused by heat from nearby magma intrusions, affecting rocks locally.
• Regional metamorphism : caused by high pressure and temperature over large areas, often related to tectonic plate collisions and deep burial.
• Dynamic metamorphism : caused by mechanical deformation and pressure in fault zones

In summary, metamorphism is the solid-state transformation of one rock type into another due to heat, pressure, and stress deep underground