The authors describe a series of pyroclastic rocks in which zeolites are largely developed. They identified two low-grade metamorphic facies: a) clinoptilolite-analcime - b) laumontite. The occurrence of wairakite and the presence of a batholithic intrusion suggest high temperature conditions considering the pressure. According to the authors, the pumpellyite-prehnite metagraywacke facies does not exist in contact metamorphism, the absence of the pumpellyite minerali and the intimate association epidote-laumontite thus being explained.