The solubility of corundum in H2O at high pressure and temperature and its implications for Al mobility in the deep crust and upper mantle

The solubility of corundum in H2O was measured at 700-1100 degrees C and 0.5-2.0 GPa using a piston-cylinder apparatus and weight-loss methods. At 700 degrees C, 0.5 GPa, Al concentration is 0.41 +/- 0.15 millimolal (1 sigma analytical error). Corundum solubility increases strongly with pressure (P) and temperature (T), reaching 2.57 +/- 0.15 millimolal at 700 degrees C, 2.0 GPa, and 27.3 +/- 1.5 millimolal at 1100 degrees C, 2.0 GPa. The results were fitted with the equation log m(Al)= 1.131 +3827/T-(2.277-7336/T)log rho H2O, where MAI is molality of Al, rho(H2O) is the density of H2O in g/cm(3), and T is in Kelvin. The data indicate that Al can have significant solubility in H2O during metamorphic and metasomatic processes in the deep crustal and upper mantle. (c) 2007 Elsevier B.V All rights reserved.