Wada Pass
Wada, Nagawa city, Chiisagata county, Nagano pref., Japan
This locality is closed to collecting.
Occurrence
Garnet in vesicules of rhyolite lava of the early Pleistocene (1.0 Ma) Wadatoge Rhyolite. It is considered that garnet grew from vapor. The Wadatoge Rhyolite was erupted from the early Pleistocene (1.5 Ma) Enrei Volcano. The chemical composition of garnets is near the boundary between spessartine and almandine, and both species were described. The age of rhyolite was determined by K-Ar radiometric dating.
Outcrop of Wadatoge Rhyolite. The massive white host is rhyolite. The reddish-brown grains in vesicules are garnte, spessartine or almandine. Garnet is associated with fine quartz crystals (Alpha quartz).
Reported Minerals
Mineral Assemblages
- Spessartine - Almandine - Quartz