Katsura Island
Kaka, Shimane village, Matsue city, Shimane pref., Japan
Occurrence
Intermediate acidic metasomatic rocks of low-T silicified zone
Chalcedony veins in rhyolite. This rhyolite is a part of the middle Miocene (15 Ma) lava dome of the submarine volcano in the Jyosoji Formation. There are many platy cooling joints. The age was determined by microfossils.
White chalcedony in rhyolite lava of the Jyosoji Formation. White veins are chalcedony. The brown host is rhyoliteic lava, a part of the lava dome. There are two platy joints from the upper right to the lower left. The chalcedony veins are roughly along the joints faces. Radial aggregates of ferrierite-Mg are in chalcedony at the boundary between chalcedony and rhyolite.
Reported Minerals
- Ferrierite-Mg
- Chalcedony
Mineral Assemblages
- Chalcedony - Ferrierite-Mg
Localities
- Narayama (Rhyolite, Ferrierite-K)
- Katsura Island (Rhyolite, Ferrierite-Mg)
- Kita-Tomida (Dacite, Chalcedony)
- Shibusawa Mine (Gypsum deposit)
- Nanataki fall (Pyrite)
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)