The thermodynamics of the Earth's crust have recently been treated in several Norwegian papers, notably by H. Ramberg ( 1-2-3) and by Jens Bugge ( 4). One of the principal conclusions of these papers is, that the chemical activity (the chemical potential, vapour-pressure) of a suibstance will increase with increasing pressure. Consequently, all minerals which are subject to stress will show a tendency to re-crystallize. This re-crystallisation must take place in the way that the ions of the mineral arre transferred to a disperse phase in places of high pressure and condense to a consolidated orderly phase when the pressure is lower. The result will be a diffusion from high to low pressure; whether this diffusion takes place through the consolidated phase or through the disperse phase is left undecided.