Phase relations concerning zeolites and aluminous clay minerals

8) Phase relations concerning zeolites and aluminous clay minerals 

5) feldspar-montmorilion ite-zeolite-silica Two, three or four of the minerals in these assemblages have been reported for assemblage 1) by Dzotsendidze and Skhirtladze (1964) Moiola (1970)  

Kaol = kaolinite Mo = beidelitic montmorillonite M 38 muscovite (or illite) ML = mixed layered minerals Anal = analcite Nat = natrolite Ze = alkali zeolites. Alkali zeolite tie-lines for specific species are not given, j) less than 100°C. 

The geological environments for these assemblages are those of weather ing, deep-sea floor sediments and continental shelf sediments, or shallow burial of these materials as sedimentary or tuffaceous rocks. 

These associations are noted by Hay (1966) as being found in sequences of sedimentary rocks or altered pyroclastics buried to depths greater than 3,000 meters and generally less than 10,000 meters. However, the limits are actually vague and the identifications imprecise. The relatively frequent occurrence and persistence of albite or potassium feldspar and alkali zeolite in such rocks leads one to believe that they can coexist stably in nature. This could be, however, a misleading conclusion based upon too few observations. The elimination of the silicic, alkali zeolites and the persistence of montmorillonite is known to exist in series of deeply buried rocks (Ii-jima, 1970 Moiola, 1970 Iijima and Hay, 1968). 

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