- Most common volatile in magma are: H2O, CO2, SO2, CO, H2S ...
In general, all volatile species are lumped into one percent value for the melt
High pressure/temperature, volatiles are in solution (no bubbles), hence lower viscosity
Just like the CO2 in a can of Coke when the can is opened, the bubbles form
- Volatile % can be as high as 20% by mass at these high pressures however, volatiles have low molecular weights and therefore can be a much larger volume of the melt
The more volatiles in a melt, the more potential for an explosive eruption when the magma gets close to the surface!