Zeolite deposits exist in almost every province and region in Cuba. They are related to back-arc sequences from Cretaceous and Paleocene- Eocene volcanic arcs, and to top sequences of the axial arc zone from a Cretaceous volcanic arc, of which the latter developed only in the central part of Cuba. Due to the transformation of volcanic shards of medium-acid composition clinoptilolite, mordenite and less widespread montmorillonite originated. Clinoptilolite substitutes volcanic shards, and mordenite is formed after it