Kyurazawa Mine
Ashio village, Nikko city, Tochigi pref., Japan
Occurrence
Albite-Epidote-hornfels facies bedded Manganese deposit
Chert-hosted bedded manganese deposit in Permian - Jurassic chert blocks of Middle Jurassic Omama Complex. The deposit has been subjected to Albite-Epidote-hornfels facies contact metamorphism by Sori Granodiorite and Kobugahara Granodiorite. Approximately 2 km apart from Kobugahara Granodiorite, 3 km from Sori Granodiorite.

The entrance of the lowest level adit of Shin-sanjin ore body of Kyurazawa mine. The adit is on the outcrop of bedded chert of Omama Complex.
Reported Minerals
- Pyrrhotite
- Sphalerite
- Galena
- Calcite
- Rhodonite
- Spessartine
- Clino-suenoite
- Pyrosmalite-(Mn)
Mineral Assemblages
- Rhodonite - Manganpyrosmalite - Calcite
- Rhodonite - Clino-suenoite
- Quartz - Spessartine
Produced metal
- year 1949: Concentrate 860 t (Mn 40 %)
- year 1950: Concentrate 790 t (Mn 40 %)
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
- Bedded Mn (Diagenesis)
- Bedded Mn (Low-T zeolite facies)
- Bedded Mn (High-T zeolite facies)
- Bedded Mn (Prehnite-Pumpellyite facies)
- Bedded Mn (Pumpellyite-Actinolite facies)
- Bedded Mn (Greenschist facies)
- Bedded Mn (Epidote-Amphibolite facies)
- Bedded Mn (Amphibolite facies)
- Bedded Mn (Albite-Epidote-hornfels facies)
- Bedded Mn (Hornblende-hornfels facies)
- Bedded Mn (Pyroxene-hornfels facies)