Ionic or atomic diffusion controls chemical exchange between and within different crystalline, melt and fluid phases. It can control the kinetics of phase transitions, the rate at which minerals grow, the degree of compositional zoning in minerals, and other important geochemical processes. Diffusion also plays a central role in the rheological properties of minerals and melts. In diffusion creep stress is accommodated through ions migrating from regions of high stress to regions of low stress. This is achieved either through bulk diffusion or grain boundary diffusion. In dislocation creep the rate-limiting step is often dislocation climb—the process where a dislocation...

First Page Preview

First page PDF preview
You do not currently have access to this article.