Home – Home – Jornals – Russian Geology and Geophysics 2009 number 12

Literature data on the coefficients of heterovalent NaSi-CaAl interdiffusion in plagioclases are analyzed. It is shown that activation energy and frequency factor decrease as the partial pressure of water and plagioclase basicity increase. A general expression has been derived for the interdiffusion coefficients of albite and anorthite asa function of the plagioclase composition (N _Pl ), temperature T (K), and water pressure (kbar):
D [см²/c] = exp {13.14 - 0.354N_Pl + 40.72/(1 + P²_H2O) - (116095 - 1037N_Pl + 139732/(1 + P²_H2O))/RT }