How does fractional crystallization shape magma and rocks?

Fractional crystallization is a key geochemical process where different minerals crystallize from magma at varying temperatures and drop away from the melt. This process changes the bulk composition of the magma over time and plays an essential role in the formation of igneous rocks. Magma itself is formed by melting the Earth's crust or mantle in settings like subduction zones, rift zones, and hotspots before cooling underground or erupting as lava.

What we know

• Fractional crystallization is a geochemical and physical process operating within the Earth's crust and mantle where different minerals crystallize and drop away from the melt at different temperatures. [1, 2]
• Magma is produced by the melting of the mantle or crust in tectonic settings including subduction zones, continental rift zones, mid-ocean ridges, and hotspots. [4]
• During its storage in the crust, magma composition can be modified by fractional crystallization, crustal contamination, magma mixing, and degassing. [4]
• Following ascent through the crust, magma may either feed a volcano as lava or solidify underground to form intrusive bodies like dikes, sills, plutons, or batholiths. [4]

Where to go next

• the bigger pictureWhat is igneous differentiation?
• what caused itHow do tectonic settings create magma?
• what followedWhat underground intrusions does magma form?
• how we knowWhere has magma been encountered during drilling?
• compared withHow does fractional crystallization affect sedimentary rocks?
• an unexpected connectionWhy does a progressive rock band share its name with molten subsurface rock?The French progressive rock band Magma shares its name with the geological concept of molten rock, having been founded in 1969 by drummer Christian Vander to tell mythical stories of alien colonization.

Sources

• [1]fractional crystallization (Wikidata Q577904) · CC0 1.0
• [2]Fractional crystallization (geology) · CC BY-SA 4.0
• [3]Igneous differentiation · CC BY-SA 4.0
• [4]Magma · CC BY-SA 4.0
• [5]Magma (band) · CC BY-SA 4.0