"Limestone inclusions in granite show a skarn armour made up of definite mineral zones. From the limestone side these are in order: grossular zone (with or without idocrase), clinozoisite zone, plagioclase-pyroxene zone, and finally a hornblendic or dioritic zone that passes into the biotite-granite or granodiorite of the district. These different zones were not static but moved into the limestone, each zone replacing the one preceding it and being replaced by the zone following it. A mechanism by which limestone inclusions disappear in granite is clearly exemplified."