The effect of volatiles on the properties of magmatic melts

Systematic experimental studies at 750-1400 degrees C and 1 atm-7 kbar have shown the H (sub 2) solubility in an albite melt at 1300 degrees C is two orders of magnitude lower than the H (sub 2) O solubility and approx twice as high as that of CO (sub 2) . These findings are thermodynamically consistent with the fact that the albite melting T decreases considerably under H (sub 2) P. The results are used to derive the general viscosity patterns in magmatic melts and to study new facets of the interaction of volatiles (H (sub 2) O, H (sub 2) , F, Cl) and melts. A new model for calculation of the viscosity and activation energy of viscous flow in a series of ultrabasic to acid magmas is described.