Electron microprobe analyses were made of diffusion-controlled concentration gradients of Ar in quenched samples. The temperature dependence of Ar diffusivity at 400 to 900C under 1200bar was described by:

D(cm2/s) = 8.71 x 10-6 exp[-24.1(kcal/mol)/RT]

M.R.Carroll, E.M.Stolper: Geochimica et Cosmochimica Acta, 1991, 55[1], 211-25