Magmatic water

It plays a key role in assessing the crystallization of igneous rocks, particularly silicates, as well as the rheology and evolution of magma chambers.

[2] An abundance of volatiles within magma chambers decreases viscosity and leads to the formation of minerals bearing halogens, including chloride and hydroxide groups.

In addition, the relative abundance of volatiles varies within basaltic, andesitic, and rhyolitic magma chambers, leading to some volcanoes being exceedingly more explosive than others.

An abundance of magmatic water has been shown to lead to high-grade deformation, altering the amount of δ18O and δ2H within host rocks.

[3] Volatiles, particularly water and carbon dioxide, significantly impact the behavior of each form of magma differently.

[4],[2] Magma with a high concentration of volatiles has a significant reduction in temperature of up to hundreds of degrees, which reduces its inherent viscosity.

For instance, magmatic water leads to the crystallization of several minerals abundant in hydroxyl- or halogenated-groups, including garnets.

[1], [3] The composition of silica within basaltic magma ranges from 45-55 weight percent (wt.%), or mass fraction of a species.

Rhyolitic magma is felsic and the most abundant in silica, potassium, and sodium but the lowest in iron, magnesium, and calcium.

Degassing occurs when hydrous magma is uplifted, gradually converting the dissolved water to aqueous phase.

Dependent on which cation the hydroxyl is bound to, it significantly impacts the properties of a volcanic eruption, particularly its explosiveness.

[9] During unusually high temperature and pressure conditions exceeding 374 °C and 218 bar, water enters a supercritical fluid state and becomes no longer a liquid or a gas.

[9] Isotopic data from various locations within the Mid-Atlantic Ridge indicates the presence of mafic-to-felsic intrusive igneous rocks, including gabbro, diorite, and plagiogranite.