* Physical: the density difference between the magma (lower density) and the host rocks is a key factor. Archimedes' principle is the one who acts. The surrounding rocks exert an upward thrust that moves the crustal magma to levels where their density is equated with the host rocks. It may happen that the density remains below the rocks of the environment and that the magma is detained its vertical ascent, the factor involved here are local efforts. If the efforts of the magma pressure can not overcome the resistance of the rocks magma vertically looking for a new way of moving through a plane of weakness such as a stratigraphic unconformity, anisotropy of the medium as fault planes, hinges of [[fold]]s, etc (Figure 3). | * Physical: the density difference between the magma (lower density) and the host rocks is a key factor. Archimedes' principle is the one who acts. The surrounding rocks exert an upward thrust that moves the crustal magma to levels where their density is equated with the host rocks. It may happen that the density remains below the rocks of the environment and that the magma is detained its vertical ascent, the factor involved here are local efforts. If the efforts of the magma pressure can not overcome the resistance of the rocks magma vertically looking for a new way of moving through a plane of weakness such as a stratigraphic unconformity, anisotropy of the medium as fault planes, hinges of [[fold]]s, etc (Figure 3). |