Yoshimi
Hattanda, Yoshimi city, Hiki county, Saitama pref., Japan
Occurrence
Greenschist facies metamorphic rocks
Ba and Sr-bearing zeolites in sandstone and mudstone of the accretionary complex subjected to Greenschist facies metamorphism as a low grade part of the early Paleocene (64 Ma) high-P Yoshimi metamorphic rocks. The Yoshimi metamorphic rocks may be a part of the Sambagawa metamorphic belt. The age of the zeolite formation has not been reported but is younger than metamorphism. The metamorphic age was determined by U-Pb SHRIMP dating of Zircon.
Outcrop of the Yoshimi metamorphic rocks. White veins in the outcrop are phillipsite-Ca and phillipsite-Ba with minor amount of chabazite-Ca and calcite. The protolith of the gray host rock is probably quartz-rich sandstone and mudstone.
Reported Minerals
- Phillipsite-Ca
- Phillipsite-Ba
- Chabazite-Ca
- Thomsonite
- Analcime
- Calcite
Mineral Assemblages
- Phillipsite-Ca - Chabazite-Ca
Localities
- Kami-Nagatoro (Stilpnomelane, High-P)
- Banjo (Glaucophane, High-P)
- Yamabuki creek (Hematite, High-P)
- Yoshimi (Zeolite, High-P)
- Kami-Suwa (Chloritoid, Middle-P)
- Takarayama Mine (Quartz, Middle-P)
Related Occurrences
- Albite-Epidote-hornfels facies
- Hornblende-hornfels facies
- Pyroxene-hornfels facies
- Sanidinite-hornfels facies
- Pumpellyite-Actinolite facies
- Blueschist facies
- Epidote-Amphibolite facies
- Eclogite facies
- Ultrahigh-pressure faices