Kawazura Mine

Hikoma village, Sano city, Tochigi pref., Japan

Synonym

Higashiyama Mine

Occurrence

Albite-Epidote-hornfels facies bedded Manganese deposit

Chert-hosted bedded manganese deposit in the Late Triassic (220 Ma) to Early Jurassic (175 Ma) chert block of the Late Jurassic (145 Ma) Kurohone-Kiryu Unit. The deposit has been subjected to weak Albite-Epidote-hornfels facies contact metamorphism by the Sori granodiorite in the Late Cretaceous (90 Ma). The Kurohone-Kiryu Unit corresponds to the Kanayama Unit of the Tamba-Mino-Ashio accretionary complex. The Sori granodiorite is S-type (Ilmenite-series). Approximately 10 km apart from the Sori granodiorite, the heat source. Ages of sedimentary rocks were determined by radiolarians, and granodiorite by K-Ar or Ar-Ar radiometric dating of biotite.

Reported Minerals

Graphite
Hausmannite
Manganosite
Jacobsite
Pyrochroite
Sonolite
Alleghanyite
Cryptomelane
Pyrolusite
Feitknechtite
Pyrite
Siderite
Barite
Gypsum
Rhodonite
Tephroite
Braunite
Spessartine
Caryopilite(Bementite)

Mineral Assemblages

Hausmannite - Manganosite - Tephroite - Jacobsite - Pyrochroite - Sonolite - Alleghanyite - Rhodochrosite
Quartz - Rhodonite - Braunite
Quartz - Rhodonite - Spessartine - Caryopilite
Quartz - Graphite

History

Manganese oxide ore was mined.
1958: Began to mine maganese ore.

Localities

Mogurazawa Mine (V-bearing minerals)
Kyurazawa Mine (Pyrosmalite-(Mn))
Kurokawa Mine (Ni-bearing minerals)
Kawazura Mine (Low AE facies)
Daikei Mine (AE facies)
Ittanda Mine (Neotocite)

Related Occurrences

Other Occurrences