Metamorphic rocks are rocks that started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form.
Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.
Metamorphism is caused by rocks undergoing changes in temperatures in pressure and are also sometimes subjected to hydrothermal fluids and differential stress.
The Metamorphism occurs because some minerals are stable only under certain conditions of pressure and temperature.
The most common form of metamorphism is regional metamorphism which is how most metamorphic rocks form.
These regional metamorphism rocks were typically exposed to tectonic forces and associated high pressures and temperatures.
The importance of metamorphism is that metamorphic rocks and minerals have economic value and because mineralogical and structural adjustment of solid rocks to physical and chemical conditions that have been imposed at depths below the near surface zones of weathering and diagenesis and which differ from conditions under which the rocks in question originated.
Metamorphism is the alteration of the composition or structure of a rock by heat, pressure, or other natural agency.
An example of Metamorphism is the transformation of existing rock to rock with a different mineral composition or texture.
Metamorphism is the process that changes preexisting rocks into new forms because of increases in temperature, pressure, and chemically active fluids.
Metamorphism may affect igneous, sedimentary, or other metamorphic rocks.
The three types of metamorphism are Contact, Regional, and Dynamic metamorphism.
Contact Metamorphism occurs when magma comes in contact with an already existing body of rock.
Metamorphism occurs because some minerals are stable only under certain conditions of pressure and temperature.
When pressure and temperature change, chemical reactions occur to cause the minerals in the rock to change to an assemblage that is stable at the new pressure and temperature conditions.
The word metamorphism is taken from the Greek for “change of form”; metamorphic rocks are derived from igneous or sedimentary rocks that have altered their form (recrystallized) as a result of changes in their physical environment.
New minerals are created either by rearrangement of mineral components or by reactions with fluids that enter the rocks.
Pressure or temperature can even change previously metamorphosed rocks into new types.
Metamorphic rocks are often squished, smeared out, and folded.
There are two major kinds of metamorphism: regional and contact.
Most metamorphic rocks are the result of regional metamorphism (also called dynamothermal metamorphism).
Metamorphic rocks are broadly classified as foliated or non-foliated.
Non-foliated metamorphic rocks do not have aligned mineral crystals.
Non-foliated rocks form when pressure is uniform, or near the surface where pressure is very low.
Regional metamorphism is the most common form of metamorphism that occurs in broad areas.
It is caused by high temperature and pressure that resulted from the thickening of the crust and plate tectonics.
Most metamorphism takes place in a zone that begins several kilometers below the surface and extends into the upper mantle.
We often find metamorphic rocks in mountain ranges where high pressures squeezed the rocks together and they piled up to form ranges such as the Himalayas, Alps, and the Rocky Mountains.
Metamorphic rocks are forming deep in the core of these mountain ranges.