TrekGEO > Mineral Trail > Koshinetsu region > Yamanashi pref. > Kusama Mine

Japanese page

Kusama Mine

Shimobe, Minobu city, Minami-Koma county, Yamanashi pref., Japan


Shimobe Mine


High-T zeolite facies bedded manganese deposit

Cu-Mn deposit in mudstone of the late Miocene (11 Ma) Shimobe Formation, the bottom member of the Fujikawa Group. The deposit is at the boundary between mudstone and upper basaltic pyroclastics. The deposit has been subjected to Zeolite facies metamorphism. The Fujikawa group can be interpreted as sediments at the back-arc basin of the old Izu-Ogasawara arc. Ages of sedimentary rocks were determined by microfossils.

Kusama Mine

Outcrop of mudstone of the Shimobe Formation near an adit. The adit is at the boundary between mudstone and basaltic lava. This deposit was classified to bedded manganese deposit here, although this can be a sediment-hosted copper deposit. This mine is generally known as copper mine but there is a record that this mine was developed for copper.

Reported Minerals

Mineral Assemblages

  • Hausmannite - Rhodochrosite - Caryopilite
  • Hematite - Bustamite - Piemontite
  • Hematite - Copper
  • Hematite - Chalcopyrite - Malachite
Copyright (c) 2015 NariNari, All Rights Reserved.