This study is a survey of zeolites in the andesitic rocks of the Central Coastal Range (CCR) of eastern Taiwan. Methods of the study include field observations and laboratory techniques such as X-ray diffraction, petrography, and scanning electron microscopy.
The duration of exposure to seawater is considered as the main factor influencing the amount of zeolites in submarine erupted andesitic rocks of the CCR. The longer the andesitic rocks are exposed to seawater, the larger the amount of zeolites would be in them. On the other hand, the species of zeolite and related authigenic minerals in the andesitic rocks of the CCR are presumably controlled by the kind of their phenocrysts which are the essential minerals suffered from alteration.