Chapter 7: Metamorphic Rocks

Rock Cycle

Rock Cycle

The succession of events that results in the transformation of Earth materials from one rock type to another.

Forming Igneous Rock

Requires heating and melting of rock components.

Forming Sedimentary Rocks

Requires erosion, transportation, and deposition of rock materials.

Forming Metamorphic Rocks

Requires burial and/or heating of pre-existing rocks.

Geochemical Cycles

Involve primarily physical components of the Earth System.

Biogeochemical Cycles

Involve both physical and living components of the Earth System.

Metamorphic Rock

Forms when a pre-existing rock (protolith) undergoes a solid-state change in response to the modification of its environment.

Protolith

The original rock that has undergone metamorphism.

Metamorphism

The process by which one kind of rock forms into a different type of rock.

Foliated Metamorphic Rocks

Rocks with parallel surfaces or layers that can occur due to preferred mineral orientation or layering.

Nonfoliated Metamorphic Rocks

Rocks that do not exhibit foliation and have minerals that recrystallized or grew during metamorphism.

Metamorphic Grade

Represents the intensity of metamorphism based on the amount or degree of metamorphic change.

Metamorphic Zone

The region between two metamorphic isograds, typically named after an index mineral found within the region.

Thermal Metamorphism

Occurs due to high temperatures without pressure changes, altering rock mineralogy.

Contact Metamorphism

Results from rocks coming into contact with magma, leading to changes in mineralogy and texture.