The hydraulic flow involved is usually due to hydrothermal circulation.
The source of the heating for the water in the hydrothermal circulation is still under discussion.
Hydration of minerals occurs generally in concert with hydrothermal circulation which may be driven by tectonic or igneous activity.
Minerals in the marginal facies include zeolite minerals, micas, kaolinite and clays, typical of post-eruption hydrothermal circulation.
It was formed by hydrothermal circulation previous to the 1064 eruption of Popocatépetl, located in the town of La Libertad.
The area underlying the silo's site contain minerals indicating hydrothermal circulation and alteration.
This was attributed to hydrothermal circulation accelerating the cooling of the magma over the nine to ten years since the end of the eruption.
Sometimes granites erupt to surface as volcanoes, and copper mineralisation forms during this phase when the granite and volcanic rocks cool via hydrothermal circulation.
The combined processes of volcanism, tectonic fracturing and hydrothermal circulation together form massive deposits of sulphides.
They also examine volcanic processes, mantle circulation, hydrothermal circulation, magma genesis, and crustal formation.