Stilbite-Mordenite zone
Chemical Process (Alteration) - Open system under ground (Alkaline metasomatism)
Correlated: Low-T zeolite facies
Synonym
Zeolite zone
Index Minerals
Stilbite, Mordenite
Required Geological Setting
Occurrence
Metasomatic zone formed by alkaline hydrothermal fluid of 50-100 degree associated with Basaltic magma activities. This alteration is a part of Zeolitization. Stilbite-Mordenite zone may be associated with Hydrothermal Au-Ag deposits. The water related to the alteration reaction of the stilbite-mordenite zone is meteoric water and/or magmatic water, and the water/rock ratio is more than a few tens times. It means that minerals were formed by reactions of the open system. On the other hand, the water related to the diagenesis is interstitial water in sediments, and the water/rock ratio is less than ten times. Minerals by diagenesis were formed by reactions of the closed system.
Change of mineral assemblages
- [ Appear ] Stilbite, Mordenite, Chabazite
Mineral Assemblages
- [ Felsic Rocks ] Stilbite, Chabazite, (Calcite)
- [ Mafic Rocks ] Mordenite, Chabazite, (Calcite)
Localities
Related Occurrences
- Halloysite zone (Alunite zone, Argillized zone)
- Kaolinite zone (Alunite zone, Argillized zone)
- Minamiite-Alunite zone (Alunite zone)
- Pyrophyllite zone
- Smectite zone (Argillized zone)
- Interstratified mineral zone (Argillized zone)
- Illite-Chlorite zone (Propylite zone)
- Epidote-Actinolite zone
- Stilbite-Mordenite zone (Zeolite zone)
- Heulandite-Analcime zone (Zeolite zone)
- Laumontite-Albite zone (Zeolite z., Propylite z.)
- Wairakite-Albite zone (Zeolite zone)