Onara
Sanbagawa, Fujioka city, Gunma pref., Japan
"No Trespassing" sign was erected
Occurrence
Greenschist facies serpentinite
Serpentinite in Mikabu Unit of Sanbagawa Belt. This serpentinite block is lens-shaped and is concordant with schistosity of Sanbagawa Metamorphic Rocks. This serpentinite block is associated with metamorphosed mafic volcanic rocks. This locality had been a Ni mine and is a quarry for serpentinite.
Outcrop of serpentinite in Mikabu Unit. The dark green outcrop is uniformly composed of serpentinite.
Reported Minerals
- Piemontite
- Albite
- Pyrite
- Malachite
- Fuchsite
- Magnetite
- Hydromagnesite
- Brucite
- Tremolite
- Serpentine
- Pumpellyite
- Clinothulite
- Sursassite
- Aragonite
Mineral Assemblages
- Piemontite - Albite - Quartz - Muscovite
- Epidote -Pyrite - Malachite - Quartz - Albite
- Quartz - Albite - Muscovite - Graphite - Fuchsite
- Serpentine - Magnetite - Hydromagnesite - Aragonite
- Serpentine - Brucite - Tremolite
- Pumpellyite
- Albite - Quartz - Clinozoisite - Sursassite
Localities
- Orihara (Talc, High-P)
- Matsunaga Mine (Talc, High-P)
- Arai (Diopside, High-P)
- Osaka (Ophicalcite, High-P)
- Miyazawa (Dolomite, High-P)
- Onara (Fe-Ni, High-P)
- Yashio mine (Fe-Cr, High-P)