Metamorphic rock Metamorphic rock Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure ( or more), causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by texture and by chemical and mineral assemblage (metamorphic facies). They may be formed simply by being deep beneath
Name of France suburbs. This fourth meaning is found in many place names, such as the town of Roissy-en-France, on whose territory is located Charles de Gaulle Airport. The name of the town literally means "Roissy in the "Pays de France"", and not "Roissy in the country France". Another example of the use of France in this meaning is the new "Stade de France", which was built near Saint-Denis for the 1998 Football World Cup. It was decided to call the stadium after the "Pays de France", to give it a local touch. In particular, the mayor of Saint-Denis made it very clear