TrekGEO > Mineral Trail > Koshinetsu region > Nagano pref. > Wada Pass

Japanese page

Wada Pass

Wada, Nagawa city, Chiisagata county, Nagano pref., Japan

This locality is closed to collecting.


Rhyolite vesicules

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.

Wada Pass

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


  • Kiyomizu (Lava, Osumilite)
  • Kozu Island (Lava, Osumilite)
  • Tsukigase (Lava, Osumilite)
  • Wada Pass (Lava, Spessartine)

Related Occurrences

Copyright (c) 2013 NariNari, All Rights Reserved.