What does pneumatolytic mean in geology ?
Pneumatolytic : definition
This adjective designates any geological entity formed at the end of the crystallization of a magma, between 374°C and 600°C (term derived from pneuma, the breath).
During this stage, called pneumatolysis, the transport and deposit of the mineralizing fluids takes place in the supercritical state (above 374°C, the critical temperature of water). These end-of-crystallization fluids concentrate most of the gases and rare metals of the magma (B, Be, F, Li, La, Ce, Nb, Sn, etc.), which are expressed in the form of so-called pneumatolytic minerals (beryl, tourmaline, topaz, cassiterite, rare earth phosphates, lepidolite, etc...) in pegmatites, greisens or pneumatolytic veins, often located in fractures on the periphery of the generating granite.
During this stage, called pneumatolysis, the transport and deposit of the mineralizing fluids takes place in the supercritical state (above 374°C, the critical temperature of water). These end-of-crystallization fluids concentrate most of the gases and rare metals of the magma (B, Be, F, Li, La, Ce, Nb, Sn, etc.), which are expressed in the form of so-called pneumatolytic minerals (beryl, tourmaline, topaz, cassiterite, rare earth phosphates, lepidolite, etc...) in pegmatites, greisens or pneumatolytic veins, often located in fractures on the periphery of the generating granite.