The metamorphic process occurs in specific settings, where temperature and pressure reach a certain level. Metamorphic rocks are created if the pressure is higher than 3 Kbar and the temperature is higher than 200 °C . Such settings are found in volcanic arcs, collisional mountain belts, stable continents and accretionary prisms. Contact metamorphism occurs at low pressure but high temperatures, which occurs just next to an intrusion that heats the surrounding rock. These changes form specific rocks with a specific mineral content that depends on the protolith, temperature and pressure.