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During cooling, crystals will form from the melt. Thus, the crystal/melt ratio increases, generating a magma, a crystal-mush, and finally a cumulate rock. A crystal mush is magma that contains a significant amount of crystals (up to 50% of the volume) suspended in the liquid phase (melt). [1]
High-temperature fractional crystallization of relatively water-poor granite magmas may produce single-alkali-feldspar granite, and lower-temperature crystallization of relatively water-rich magma may produce two-feldspar granite. [13] During the process of fractional crystallization, melts become enriched in incompatible elements. [14]
In addition, numerous studies have focused on looking at the partition coefficients of certain elements in the basaltic magma to characterize the composition of oceanic crust. [2] By having a way to measure the composition of elements in the crust and mantle given a mineral sample, compatibility allows relative concentrations of a particular ...
Magma mixing is a common process in volcanic magma chambers, which are open-system chambers where magmas enter the chamber, [10] undergo some form of assimilation, fractional crystallisation and partial melt extraction (via eruption of lava), and are replenished.
For instance, a magma of gabbroic composition can produce a residual melt of granitic composition if early formed crystals are separated from the magma. Gabbro may have a liquidus temperature near 1,200 °C, and the derivative granite-composition melt may have a liquidus temperature as low as about 700 °C.
The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic magma, which is high in magnesium and iron and produces basalt or gabbro, as it fractionally crystallizes to become a felsic magma, which is low in ...
More typically, they are mixes of melt and crystals, and sometimes also of gas bubbles. [15] Melt, crystals, and bubbles usually have different densities, and so they can separate as magmas evolve. [89] As magma cools, minerals typically crystallize from the melt at different temperatures. This resembles the original melting process in reverse.
[1], [3] The composition of silica within basaltic magma ranges from 45-55 weight percent (wt.%), or mass fraction of a species. [1] It forms in temperatures ranging from approximately 1830 °F to 2200 °F. [1], [3] Basaltic magma has the lowest viscosity and volatiles content, yet still may be up to 100,000 times more viscous than water. [1]