Taguchi Mine

This locality is strictly closed to collecting.

Occurrence

Amphibolite facies bedded manganese deposit

Bedded manganese deposit in pelitic schist of the low-pressure Ryoke metamorphic belt. The protolith of the Ryoke metamorphic rocks is the Middle Jurassic (170 Ma) accretionary complex, a part of the Tamba-Mino-Ashio accretionary complex. The deposit has been subjected to Amphibolite facies metamorphism by the Late Cretaceous (100 Ma) low-pressure Ryoke metamorphism, and contact metamorphism by the Late Cretaceous (85 Ma) Kiyosaki Granodiorite of the Inagawa Granite. Pegmatite veins by the Kiyosaki Granodiorite were intruded in the deposit. The Kiyosaki Granodiorite and the Inagawa Granite are S-type (Ilmenite-series). Approximately 2.5 km apart from the Kiyosaki Granodiorite, the heat source. Ages of sedimentary rocks were determined by radiolarians, metamorphic age by CHIME dating, and ages of granidoids by Rb-Sr radiometric dating and K-Ar radiometric dating of biotite. The Rb-Sr radiometric dating of Yoshimuraite-Rhodonite-Phlogopite ores indicates 71-80 Ma.

Reported Minerals

• Copper
• Graphite
• Alabandite
• Pyrrhotite
• Cobaltite
• Molybdenite
• Gersdorffite
• Chalcopyrite
• Galena
• Nickeline
• Pyrite
• Sphalerite
• Jacobsite
• Manganosite
• Pyrochroite
• Feitknechtite
• Hausmannite
• Pyrophanite
• Alleghanyite
• Cryptomelane
• Galaxite
• Hematite
• Manganite
• Uraninite
• Rhodochrosite
• Niahite?
• Barite
• Aragonite?
• Erythrite
• Apatite
• Spessartine
• Almandine
• Sonolite
• Tephroite
• Rhodonite
• Pyroxmangite
• Aegirine
• Manganocummingtonite
• Richterite
• Yoshimuraite
• Phlogopite
• Shirozulite
• Haradaite
• Schorl
• Potassium feldspar
• Celsian?
• Kinoshitalite
• Welinite
• Neotocite
• Caryopilite("Bementite")

Mineral Assemblages

• Rhodonite - Pyrrhotite
• Rhodonite - Quartz - Molybdenite
• Rhodonite - Neotocite - Pyroxmangite
• Rhodonite - Sonolite
• Hausmannite - Jacobsite - Alleghanyite - Sonolite
• Rhodonite - Tephroite
• Quartz - Richterite - Yoshimuraite
• Rhodonite - Phlogopite - Quartz
• Rhodonite - Manganocummingtonite
• Hausmannite - Rhodochrosite - Shirozulite
• Quartz - Feldspar - Biotite - Almandine - Schorl
• Rhodonite - Quartz - Cobaltite - Erythrite

Details of the mine

Taguchi mine includes the Urayama deposit, Kaiten deposit, and Eboshi deposit. These deposits were mined from 1949 to 1960's. Mined primary ore is approximately 20 million tons.