Metamorphism, which takes place over the wide regions of the crust is known as regional metamorphism. The majority of the regionally metamorphosed rocks takes place in the regions, which have gone through deformation at the time of an orogenic event.
Gneiss is only produced by regional metamorphism. Gneiss can be produced by the regional metamorphism of distinct kinds of rocks like shale or granite. It refers to a high-grade metamorphic rock, which signifies that it is produced at high pressures and temperatures.
