They are formed by the confining heat and pressure that they derive from the physical and chemical alteration of the igneous and the sedimentary rocks. The rocks undergo es a regional metamorphism and involve a larger body of rocks that occur over a wider area.
Typically are associated with mountain building and orogenic events and display a distinct band of mineral and colors, which is called foliation.
<u>The force that drives these rocks to the various forms are those of the plate tectonics and includes the separating rides and the subducting zone along wit the continental collisions.</u>
