Crystal mush

[3] Seismic investigation offers strong evidence for the existence of crystal mushes rather than fully liquid magmatic bodies.

[1] Crystal mushes can have a wide range of mineral and chemical compositions, from mafic (SiO2-poor, MgO-rich) to felsic (SiO2-rich, MgO-poor).

[5] The initial fluid can form crystals (solid phase) by cooling down and by adding a certain water's concentration.

[6] The rapid increase in the crystal content over a short temperature interval generates ideal rheological conditions for melt extraction.

The buoyant, lighter magmas extracted from the crystal mush can ascend through the crust and form plutonic complexes.

This also halts convection in the system, and the progressive accumulation of crystals increases the efficiency of expulsion of melt from the underlying parts of the chamber due to loading.

This process is expressed by a high fraction of bubbles that drive the liquid phase toward the earth surface.

The “crystal mush” is a leading and most promising model[10][12] of magma bodies, that supported by findings (ignimbrites) on the surface, although there are some controversial aspects.

These fluids, lighter than the magma they were once in, exsolve and rise up to even shallower crust; potentially forming ore deposits.

Micro-textural and geochemical analyses are interpreted to directly link ore formation to the flow of mineralising fluids through palaeo-porosity within once permeable crystal mush dykes.

It is believed these crystal mush dykes acted as conduits for porphyry copper deposit mineralising fluids from deep portions of underlying magmas.