Untitled Flashcards Set

Ultramafic magma

Contains less than 45% silica.

Mafic magma

Contains 45%–52% silica.

Intermediate magma

Contains 53%–65% silica.

Felsic magma

Contains more than 65% silica.

Viscosity

A measure of a fluid's resistance to flow, affected by temperature and composition.

Aphanitic texture

A texture of igneous rocks indicating rapid cooling.

Phaneritic texture

A texture of igneous rocks indicating slow cooling.

Bowen's reaction series

A sequence that shows which minerals crystallize from cooling mafic magma.

Volcanic rocks

Also known as extrusive rocks, formed from lava that cools on the Earth's surface.

Plutonic rocks

Also known as intrusive rocks, formed from magma that cools beneath the Earth’s surface.

Pegmatite

An igneous rock formed from water-rich magma, resulting in very large minerals.

Batholith

A large pluton formed from multiple magma intrusions over time.

Volcanic gases

Gases emitted during a volcanic eruption, primarily composed of water vapor.

Aa lava

A type of lava flow that is jagged and angular.

Pahoehoe lava

A type of lava flow that is smooth and wrinkled.

Volcanic Explosivity Index (VEI)

A scale that measures the explosiveness of volcanic eruptions.

Lithification

The process of sediments becoming sedimentary rock through compaction and cementation.

Index minerals

Minerals that form under specific temperature and pressure conditions, aiding in identifying metamorphic environments.

Foliated rocks

Metamorphic rocks with a preferred orientation of minerals due to pressure.

Nonfoliated rocks

Metamorphic rocks that lack a preferred orientation of minerals.