Contact Metamorphism is a local type of metamorphism that develops at the contact of hot igneous intrusions and the surrounding rocks into which they intrude. The contact metamorphism is driven entirely by addition of heat into the surrounding rocks.
http://darkwing.uoregon.edu/~drt/Classes/201_99/Rice/Metamorphic.html
This pressure and temperature environment is referred to as Metamorphic Facies. (This is similar to the concept of sedimentary facies, in that a sedimentary facies is also a set of environmental conditions present during deposition). The sequence of metamorphic facies observed in any metamorphic terrain, depends on the geothermal gradient that was present during metamorphism.
http://www.tulane.edu/~sanelson/eens211/metamorphic_facies.htm
There are several ways that metamorphic rocks form at or near plate boundaries. There is localized metamorphism called contact metamorphism. Each of these types of metamorphism produces typical metamorphic rocks, but they may occur in different sequences.
https://www.msnucleus.org/membership/html/jh/earth/metamorphic/lesson1/metamorphic1e.html
As such it is a process that is usually associated with convergent plate tectonic boundaries. In this type of environment, folding and differential stress are common; consequently foliation is a common feature of regionally metamorphosed rocks.
http://darkwing.uoregon.edu/~drt/Classes/201_99/Rice/Metamorphic.html
Metamorphism affecting a large area or regional metamorphism involves large increases of temperature and pressure. Contact metamorphism is common at both convergent and divergent plate boundaries, in areas where molten rock is produced. Regional metamorphism largely occurs at convergent plate boundaries. Each of these types of metamorphism produces typical metamorphic rocks, but they may occur in different sequences. For example, both regional and contact metamorphism produce schists and shales.
https://www.msnucleus.org/membership/html/jh/earth/metamorphic/lesson1/metamorphic1e.html
In general, metamorphic rocks do not drastically change chemical composition during metamorphism, except in the special case where metasomatism is involved (such as in the production of skarns). The changes in mineral assemblages are due to changes in the temperature and pressure conditions of metamorphism.
http://www.tulane.edu/~sanelson/eens211/metamorphic_facies.htm
There are two primary types of metamorphism: Regional Metamorphism occurs on a large scale, typically involving hundreds of square kilometers of surface area. It is the most widespread of the metamorphic types and is typical of the major fold-mountain belts such as the Appalachians, Himalayas, Alps or Rocky Mountains.
http://darkwing.uoregon.edu/~drt/Classes/201_99/Rice/Metamorphic.html
The process of metamorphism is one that changes or alters either the mineralogy or the texture, but typically both, of some pre-existing rock. Metamorphic rocks are consequently rocks that have undergone a change or metamorphosis from a previous state as a sedimentary, igneous or even another metamorphic rock.
http://darkwing.uoregon.edu/~drt/Classes/201_99/Rice/Metamorphic.html
Thus, if we know the facies of metamorphic rocks in the region, we can determine what the geothermal gradient must have been like at the time the metamorphism occurred. This relationship between geothermal gradient and metamorphism will be the central theme of our discussion of metamorphism and plate tectonics.
http://www.tulane.edu/~sanelson/eens211/metamorphic_facies.htm
Usually this occurs near molten magma or lava, under high temperature and low pressure. Metamorphism affecting a large area or regional metamorphism involves large increases of temperature and pressure. Each of these types of metamorphism produces typical metamorphic rocks, but they may occur in different sequences.
https://www.msnucleus.org/membership/html/jh/earth/metamorphic/lesson1/metamorphic1e.html
which type of plate boundary is associated with regional metamorphism
Convergent plate tectonic boundaries are associated with regional metamorphism. A convergent plate tectonic boundary is associated with regional metamorphism.  