1999 年 108 巻 2 号 p. 132-149
This paper reviews recent advances in the analysis of diffusion in garnet in relation to efforts to evaluate the time scale of metamorphism. First, the basic concept of diffusion in crystals (volume diffusion) is presented to clarify the cumbersome terminology in the study of diffusion, the usage of which is sometimes confused. Then some physical and mathematical treatments for analyzing multi-component diffusion, such as the mean-field theory and the eigen vector analysis are discussed in detail. Finally, efforts to evaluate the time scale of metamorphism by Ganguly et al. (1996) using a natural garnet-garnet diffusion couple is critically discussed.