Metamorphism and Metamorphic Rocks

A set of 20 vocabulary flashcards designed to help students review key concepts and terms related to metamorphism and metamorphic rocks for their upcoming exam.

Metamorphism

The process by which rocks change due to new conditions, forming rocks with new properties.

Metamorphic Rocks

Rocks that have transformed from parent rocks under new conditions.

Agents of Metamorphism

Factors that affect the transformation of rocks during metamorphism, including heat, pressure, and fluid activity.

Contact Metamorphism

Metamorphism that occurs when magma alters the surrounding country rock.

Dynamic/Cataclastic Metamorphism

Metamorphism that results from high differential pressures, often found near faults.

Regional Metamorphism

Metamorphism that occurs due to tectonic forces building mountains, characterized by pronounced differential stresses.

Foliation

A planar arrangement of mineral grains or structural features within a rock.

Heat (in metamorphism)

Increases the rate of chemical reactions and plays a crucial role in the metamorphic process.

Lithostatic Pressure

Pressure applied equally in all directions, resulting from the weight of overlying rocks.

Differential Stress

Unequal forces applied to the rock, often occurring during mountain building.

Fluid Activity

The presence of fluids like water and carbon dioxide that enhance metamorphism by increasing reaction rates.

Index Minerals

Minerals that form under specific conditions of temperature and pressure, used to characterize metamorphic grades.

Metamorphic Facies

Groups of metamorphic rocks formed under the same broad conditions of temperature and pressure.

Slate

A common foliated metamorphic rock formed under low-grade metamorphism.

Schist

A foliated metamorphic rock characterized by larger mineral grains and formed under higher grades of metamorphism.

Gneiss

A foliated metamorphic rock with banding, indicating significant metamorphic processes.

Marble

A nonfoliated metamorphic rock primarily composed of calcite or dolomite.

Quartzite

A nonfoliated metamorphic rock that forms from sandstone.

Temperature-Pressure Diagram

A graph that shows the conditions under which various metamorphic facies occur.

Franciscan Complex

An example of a region that exhibits the blueschist facies, indicating a former subduction zone.

Mylonites

Rocks formed under high differential pressures, typically found in narrow zones along faults.