[citation needed] Anatexis can occur in a variety of different settings, from zones of continental collision to mid-ocean ridges.
[5] Crustal anatexis is not restricted to a single tectonic setting, but rather is controlled by four primary parameters: temperature, pressure, volatile content, and rock type/composition.
[7] This heat is distributed throughout the Earth's crust by a number of different processes, including radiation, conduction, convection, and advection.
[8] Decompression melting can occur in thickened portions of the Earth's crust and may be the result of a variety of processes, including erosion, tectonic denudation, and lithospheric thinning.
[2] Depending on the tectonic setting, water can also be introduced to the system through the dehydration of a subducting hydrated oceanic plate or magmatic underplating.
Syntectonic anatectic migmatites at Hafafit region, Eastern Desert, Egypt as a part of the Nubian Shield are a good example of such crustal melts.
[3] Such reactions produce large positive volume changes within the metamorphic system causing melt enhanced embrittlement.
[4][12] This, coupled with an increasing melt fraction, alters the deformation mechanisms acting among grains and decreases the strength of the rock significantly.
[13] When the transport of melt occurs on larger scales, anatexis can lead to the ascent and emplacement of large granitic bodies in the upper crust.
[4] This process is episodic and accommodated by both ongoing regional tectonics and emplacement-generated wall rock structures allowing the pluton to spread laterally and thicken vertically.
Syntectonic anatectic migmatites at Hafafit region, Eastern Desert, Egypt, Nubian Shield provide an example of the close relation between orogeny (tectonic), metamorphism and granite generation and emplacement.