Metamorphic Rock

Metamorphic Rock is a type of rock resulting from large amounts of heat and pressure. This type of heat and pressure cannot be found on the surface of the Earth. The formation of metamorphic rock will only be found beneath the surface of the Earth.

Metamorphic characteristics are unique to those of the sedimentary and igneous rocks. Cleavage is unique to metamorphic rocks. Cleavage is a result of low amounts of temperature, that develops into a planar fabrick along which the rock will break. This is not a fracture but a type of structural discontuinuity in the rock.

Foliation is a unique characteristic to metamorphic rock aswell. Foliation is formed from differential stress and is expressed in many ways. Foliation can be the allignment of particles in a parallel orientation, or in light-dark banding, the flattening of mineral grains, or by the flattening of shapes from larger grained particles.

Light-Dark Banded Foliation



Flattening of Minerals and Rocks


Another characteristic unique to metamorphic rock is lineation, this is the allignment of minerals or allignment of deformed pebbles.

Metamorphic rocks come from the deformation and metamorphism of both sedimentary and igneous rocks.  Sedimentary rocks that undergo metamorphism such as shale will produce phyllite, schist, and gneiss. Sandstone will metamorphose into quartzite, and limestone will be changed into marble.

Igneous rocks that undergo metamorphism can form common metamorphic rocks like greenstone, greenschist, metarhyolite, deformed granite, gneiss and schist.

There are many different places around our world where metamorphic rock can be found. The Canadian Belt is the first. This large concentration of metamorphic rock flows from the Northern Atlantic to the Great Lakes and then finally up to the Artic Ocean. It is rich in Copper and Iron, two very useful resources to our society today.

This location of metamorphic rock makes for a very secluded lifestyle. Very cold seasonal temps will be dominate over most seasons.

Another Place to find metamorphic rock in the United States includes that of the eastern Side of the Appalacians.

It was in this area where there were abundances of copper and iron as well. 

The next area includes the large section of Mountains on the western side of the United States. These numerous mountain ranges have yealded very diverse metal minerals. Gold and Silver have been located in isolated areas, and then many different other metal minerals such as: copper,zinc, molybdenum, manganese, tungsten, chromite and uranium. Some of these minerals are found in decent amounts while others are not enough to allow for the United states to be self-sufficient in the metal mineral that they use.