The igneous Rocks

The igneous rocks are endogenous, that is to say that originated inside the Earth. Some are from molten material, or "puddles" that have erupted to the surface: these are the volcanic rocks. The others are formed in depth and appear only through the interplay of deformation of the crust and erosion: these are the Platonic rocks; but it is generally accepted that they also result from the crystallization of molten or partially molten material. In reality, there is absolutely no separation trench between these two groups of rocks, which are also common features, so that united them under the terms of rock "magmatic" Cycle Roche's more rarely " igneous ", the first focusing on an origin from melt, the second on the high temperatures that have led to the merger.

The origin of magmatic rocks was a major topic of discussion since the beginning of geology. It does indeed pose innumerable problems, petrological and geophysical related to the nature and condition of materials in the inner layers of the Earth.