Abstract:
For the first glance, the terms «metamorphism» and «metasomatism» seem to be similar by their notion due to sound of their common beginning. They are quite different even by their origin, though they both have appeared in the middle of XIX century, while the science of geology survived the «petrographic period» of its development. The term of «metamorphism» was formed from the Greek word «µεταμορφοω» - to transform, for meaning a change of the textural-structural image of rocks input under conditions differing from the media of their formation. The term of «metasomatism» did appear with the more detail study of rocks, namely, due to discovery of the mere fact of one mineral replacing another but with remaining form of the initial one. Therefrom, takes its origin the name of such a replacement process: «µετα» - after, «σωμα, σωματος» - body, in sum - «after, over the body», or «pseudomorphous replacement». Just this notion has been taken by K. F. Nau-mann to define the term «metasomatism» (Goldsmidt, 1933, p. 24).