Igneous Rock Flashcard

Front

What is Bowen's reaction series?

Back

A sequence that illustrates the order in which minerals crystallize from cooling magma, with olivine forming at the highest temperatures.

Front

Which mineral forms at the hottest temperature according to Bowen's reaction series?

Back

Olivine.

Front

What is obsidian?

Back

A felsic, extrusive glassy igneous rock that is shiny and has sharp edges.

Front

What is rhyolite?

Back

A felsic, extrusive (aphanitic) igneous rock.

Front

What is fractional crystallization?

Back

The process where not all minerals crystallize at the same time from a cooling magma.

Front

How does rhyolite differ from basalt?

Back

Rhyolite is typically lighter in color compared to basalt.

Front

What is the texture of igneous rocks?

Back

The texture refers to the size, shape, and arrangement of crystals in the rock.

Front

What is the difference between intrusive and extrusive igneous rocks?

Back

Intrusive rocks form from magma that cools slowly beneath the Earth's surface, while extrusive rocks form from lava that cools quickly on the surface.

Front

What is a porphyritic texture?

Back

A texture in igneous rocks characterized by large crystals (phenocrysts) embedded in a finer-grained matrix.

Front

What is the significance of crystal size in igneous rocks?

Back

Crystal size indicates the cooling rate of the magma; larger crystals form from slower cooling.