Primary magma formation mechanisms: decompression melting - hot mantle ascends and partially melts due to pressure release melting due to addition of a 'fluxing agent' such as water (e.g., subduction zones) melting due to heating by hot intrusive magma, usually basalt (e.g., melting of continental crust) Important magma evolution/modification mechanisms: magma mixing in conduits or 'magma chambers' magma contamination by partial melts or fragments of wallrocks crystal fractionation - removal of crystals formed during cooling (e.g., settling of dense ones, floating of less dense ones) Eruption & ascent What causes magmas to rise in the first place?
(pressure release; melting; due to addition of a 'fluxing agent' such as water) (hot intrusive magma; basalt; T:usually) (Eruption & ascent; causes; magmas to rise in the first place) Context(Eruption & ascent causes,List([591, 620))):(magmas; to rise; L:in the first place) (magma; mixing; in conduits)
Eruption & ascent causes,List([591, 620))
pressure release hot intrusive magma Eruption & ascent magmas magma
melting basalt causes to rise mixing
due to addition of a 'fluxing agent' such as water
T:usually
magmas to rise in the first place
L:in the first place
in conduits