Obora Path
Toi, Izu city, Shizuoka pref., Japan
Synonym
Toi-Shinden
Occurrence
Alkaline metasomatic rocks of Laumontite-Albite zone
Vesicules of the andesitic to basaltic tuff breccia of the upper part of the early Pliocene (4.0 Ma) Shirahama Group. Tuff breccia is a part of pillow lava and hyaloclastite. Andesite and basalt of the upper Shirahama Group are tholeiitic, and have been subjected to propylitization alteration. The Shirahama Group unconformably overlies the Miocene Yugashima Group. Ages of sediments were determined by microfossils and K-Ar radiometric dating.
Outcrop of andesitic to basaltic tuff breccia of the Shirahama Group. The grayish-green host is tuff breccia composed of lapilli smaller than the coin. It turned greenish by propylitization alteration. The group of tabular white crystals is yugawaralite in the open space of the tuff breccia.
Reported Minerals
- Chabazite
- Laumontite
- Mordenite
- Stellerite
- Heulandite
- Stilbite
- Wairakite
- Yugawaralite
Mineral Assemblages
- Chabazite - Wairakite - Mordenite
- Yugawaralite
- Stilbite
Localities
- Obora Path (Pillow lava)
- Sogaura (Pillow lava)
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)