Kamado Mine

Shirako, Hanno city, Saitama pref., Japan

Occurrence

Prehnite-Pumpellyite facies bedded manganese deposit

Chert-hosted bedded manganese deposit in a chert block of the Early Jurassic (175 Ma) Sumaizuku unit, a member of the Northern Chichibu accretionary complex. The Sumaizuku unit has been subjected to Prehnite-Pumpellyite facies metamorphism as a low grade part of the Sambagawa metamorphic belt in the Late Cretaceous (100 Ma). The age of chert is Permian Guadalupian (270 Ma) to Early Jurassic (190 Ma). Ages of sedimentary rocks were determined by radiolarians, and metamorphic age by K-Ar or Ar-Ar radiometric dating of muscovite. The local name of Sumaizuku unit in this locality is the Anagiri Formation.

Outcrop of side wall of an adit. Hematite-rich chert of the Sumaizuku Unit is clearly observed as red stacking layers.

Reported Minerals

Caryopilite
Jacobsite
Rhodochrosite
Braunite
Hematite
Pyrite
Chalcopyrite
Greenalite

Mineral Assemblages

Jacobsite - Rhodochrosite
Braunite - Hematite
Quartz - Greenalite - Rhodochrosite

History

1940-1945: Mn was mined for a few years during World War II.

Localities

Okura Mine (Chichibu belt, Jurassic)
Agano Mine (Chichibu belt, Jurassic)
Kamado Mine (Chichibu belt, Jurassic)
Naguri Mine (Chichibu belt, Jurassic)
Yamanaka Mine (Chichibu belt, Jurassic)
Masutomi Mine (Koma Group, Miocene)
Ochiai Mine (Koma Group, Miocene)
Tomisato Mine (Koma Group, Miocene)
Inago Mine (Tanzawa Group, Miocene)
Takamatsu Mine (Tanzawa Group, Miocene)
Dainichi Mine (Tanzawa Group, Miocene)

Related Occurrences

Other Occurrences