Geology 1050: Metamorphic Rocks Quiz 3

Metamorphic Rock

Rocks that result from solid-state alteration of preexisting rocks.

Protolith

The original rock from which a metamorphic rock forms.

Foliation

A planar fabric that cuts through the rock, often formed by metamorphism.

Recrystallization

A metamorphic process where minerals change size and shape while maintaining their composition.

Neocrystallization

The process forming new metamorphic minerals from unstable protolith minerals.

Pressure Solution

Metamorphic process where mineral grains partially dissolve under pressure.

Plastic Deformation

The softening and deforming of mineral grains under high temperature and pressure.

Differential Stress

Stress that is greater in one direction than another, affecting rock formation.

Hydrothermal Fluid

Hot water with dissolved ions and volatiles that accelerates metamorphism.

Metasomatism

Alteration of a rock by hydrothermal fluids that add or subtract elements.

Gneiss

A metamorphic rock with distinct compositional bands of light and dark minerals.

Quartzite

A non-foliated metamorphic rock that forms from quartz sandstone.

Marble

A coarsely crystalline metamorphic rock that forms from limestone.

Index Minerals

Minerals that indicate the metamorphic grade of a rock.

Metamorphic Facies

A set of mineral assemblages that indicate specific P and T conditions.

Exhumation

The process by which metamorphic rocks are brought to the surface.