Metamorphic Rocks

Vocabulary flashcards covering the concepts, textures, rock examples, and processes of metamorphism.

Metamorphism

The process in which one type of rock changes into metamorphic rock because of chemical processes or changes in temperature and pressure.

Solid-state alterations

The changes that occur during metamorphism when heat, pressure, and hot fluids cause existing minerals in a rock to transform into other minerals.

Foliated metamorphic rock

A metamorphic rock texture in which severe heat and pressure cause minerals to flatten or become needlelike, aligning them into visible bands.

Nonfoliated metamorphic rock

A metamorphic rock texture in which mineral grains are not arranged in planes or bands, typically forming blocky crystal shapes that make the rock strong and durable.

Gneiss

A foliated metamorphic rock exhibiting pronounced mineral banding, formed when rocks such as granite undergo increased pressure and high temperatures.

Slate

A foliated metamorphic rock with aligned fine-grained minerals along which the rock tends to break due to weakened chemical bonds.

Marble

A nonfoliated metamorphic rock produced from limestone under heat and pressure, widely used as a building and sculpting material.

Quartzite

A nonfoliated metamorphic rock formed when sandstone is subjected to metamorphic heat and pressure.

Hornfels

A nonfoliated metamorphic rock formed near igneous intrusions during contact metamorphism.

Regional metamorphism

A type of metamorphism that occurs across large regions of Earth's crust, usually where tectonic plates collide and generate massive heat and pressure.

Contact metamorphism

A local form of metamorphism caused by direct contact with magma, where metamorphic effects decrease with increasing distance from the intrusion.

Hydrothermal metamorphism

A process occurring when very hot water reacts with rock and alters its chemical and mineral composition.

Hydrothermal Ore Deposit

Valuable concentrations of metals such as gold, copper, zinc, tungsten, and lead, formed as hot fluids migrate through rock during metamorphism.