(Géologie) Cristallisation d'une roche sous l'effet de la pression ou de la chaleur.
Change in the structure of rock by natural agencies such as pressure or heat of introduction of new chemical substances.
Geological term referring to the changes in rocks of the Earth's crust caused by increasing pressure and temperature. The resulting rocks are metamorphic rocks. All metamorphic changes take place in solid rocks. If the rocks melt and then harden, they become igneous rocks.