User:Maggiewhelan/New sandbox

Anatexis
Anatexis (via Latin from Greek roots meaning "to melt down") in geology, refers to the differential, or partial, melting of rocks, especially in the forming of metamorphic rocks such as migmatites.

Optimum temperature conditions for crustal melting
In order to have partial melting in the middle to lower continental crust, the continental geotherm must be steepened towards much higher temperatures. The minimum temperature needed to produce partial melting in metasedimentary rocks is about 650 °C. Under these conditions, water saturated metapelites reach their solidus and produce a melt of granite composition. The "standard" geotherm at the Moho is in the 500-600 °C range which would not be optimally hot enough for anatectic melting.

Extending the continental geotherm
Situations when the continental geotherm is hotter and can induce partial melting of the crust is where "orogenic processes such as crustal thickening, lithospheric mantle thinning, and underplating of mafic magma" occur (the transfer of heat from magma into the base of the continental crust).

Role of water in production of anatectic melts
The amount of water in granitic systems controls the degree of melting at a given temperature. Very high temperatures are required to generate substantial melt if the water content of the system is low.

** where does the water come from? Pore water, hydrous minerals

Mantle melting
** find sources

Extracting melt or Melt extraction?
** discuss role of deformation in extraction of melt

Types of melting
** types of melt produced by different melting processes