TrekGEO > Mineral Trail > Chugoku region > Shimane pref. > Komaki Mine

Japanese page

Komaki Mine

Yokota, Oku-Izumo city, Nita county, Shimane pref., Japan


Pneumatolytic deposit

Pneumatolytic deposit formed in the early Paleocene (65 Ma) Komaki Granite. The Komaki Granite is intruded in the Carboniferous to Permian (350-270 Ma) limestone of the Akiyoshi Limestone Group, a member of the Akiyoshi accretionary complex. The Komaki Granite is I-type (Magnetite-series). The Akiyoshi Limestone Group is considered as the Carboniferous to Permian reef limetone, reef on the summit of the seamount in the Panthalassa (Panthalassic Ocean). Ages of limestone was determined by microfossils and coral fossils, granite by Rb-Sr whole rock isochron age and K-Ar radiometric dating of muscovite and biotite.

Reported Minerals

Mineral Assemblages

  • Quartz(Gangue) - Molybdenite - Wolframite
  • Quartz(Gangue) - Molybdenite - Ferrimolybdite
  • Almandine - Chlorite - Quartz


  • around 1900: The deposit was found during road construction.
  • 1911: Began to mine.
Copyright (c) 2015 NariNari, All Rights Reserved.