"Metamorphic" means "changed form," and this broad category of rocks indicates that the minerals and chemicals present have been significantly rearranged, usually through the action of intense heat and/or pressure. The original rocks might have been sedimentary or igneous, or even older metamorphic rocks.
Rocks of the Earth's crust which have been altered by the effects of heat, pressure or chemically active fluids.
Rocks that have been transformed in response to profound changes of temperature, pressure, and chemical environment without ever melting.
rocks which have formed from pre-existing rocks due to changes in temperature, pressure, stress or chemistry.
Rocks that have formed in the solid state in response to pronounced changes of temperature, pressure, and chemical environment.
Are formed from preexisting rocks that are subject to very high pressure and temperature, which result in the structural and chemical transformation of the preexisting rocks.
Sedimentary or igneous rocks heated and/or compressed until the minerals in the rock break down and form new minerals without melting.
are formed when igneous or sedimentary rocks are subjected to extreme heat and pressure, causing them to bend, fold, squeeze and literally, "change" shape and composition.
igneous or sedimentary rocks, which have been altered by high temperature, strong pressure or by a combination of these.
Rocks which have been subjected to high temperature, high pressure, and/or chemical alteration, resulting in the deformation or regrowth of minerals already present and the growth of new minerals from the materials already present.
Metamorphic Rocks - Igneous or sedimentary rocks that have been changed in either texture of composition by external agents after their solidification. External agents may include heat, pressure, solutions, and introduction of new chemical constituents.
Rocks that have been changed by pressure or heat but not melted.
Great pressures and high temperatures can change, or metamorphose, rocks. Marble, for example, is a metamorphic rock formed from limestone. See also igneous and sedimentary rocks.
Rocks which have undergone a change in texture or composition as the result of heat and/or pressure.
Sedimentary rocks which have undergone alteration, generally by the action of heat, subsequently to their deposition and consolidation. 122
have formed from another, preexisting rock that was subjected to heat and/or pressure
Rocks that have been changed by heat and/or pressure to form new rocks consisting of new minerals.
