Nakatatsu Mine
Kami-Ono, Ono city, Fukui pref., Japan
Synonym
Ohira Mine, Senno Mine, Misaka Mine
Occurrence
Moderate-T hydrothermal skarn deposit
Skarn formed in the Carboniferous Early Mississippian (350 Ma) limestone of the Fujikura Formation in the Hida metamorphic belt by contact metamorphism of the Late Triassic (220 Ma) Funatsu Granitic Rocks. The moderate temperature hydrothermal deposit associated with the skarn was formed by the Late Cretaceous (66 Ma) quartz porphyry dike, and the Mo-bearing high temperature hydrothermal deposit in the Funatsu Granitic Rocks near the Senno deposit was formed in the early Eocene (54 Ma). The Hida metamorphic belt was formed by the collision of the Yangtze Craton with the North China Craton. The Hida metamorphic rocks had been subjected to Granulite facies metamorphism as a part of the medium-P Hida metamorphism in the Ordovician to Caboniferous (450-300 Ma), Epidote-Amphibolite facies metamorphism in the Middle Triassic (240 Ma), and Greenschist facies metamorphism by the Late Triassic (220 Ma) Funatsu Granitic Rocks. The Funatsu Granitic rocks and quartz porphyry are I-type (Magnetite-series). The sulfide deposits are in contact with the quartz porphyry dikes. The age of limestone was determined by coral fossils, metamorphic age by K-Ar and Rb-Sr radiometric dating, granitic rocks by Th-Pb and SHRIMP dating, and deposit ages by K-Ar radiometric dating.
Reported Minerals
- Calcite
- Magnetite
- Pyrite
- Sphalerite
- Galena
- Arsenopyrite
- Pyrrhotite
- Greenockite
- Bustamite
- Molybdenite
- Covellite
- Grossular
- Wollastonite
- Hedenbergite
- Hornblende
- Wulfenite
- Rosasite
- Chrysocolla
- Brochantite
- Azurite
- Hemimorphite
- Mimetite
- Cerussite
- Goethite
Mineral Assemblages
- Calcite - Wollastonite
- Quartz - Molybdenite
- Limonite - Hemimorphite - Wulfenite
- Sphalerite - Greenockite
Details of the mine
Main products are cupper, lead, and zinc. The Ohira mine and the Senno mine in the Senno valley, and the Fukasaka mine in the Fujikura valley were united to be the Nakatatsu mine.
History
- 1250: Nakayama deposit, Ningyo deposit, and Minami-Senno deposit were found.
- 1868: Mr. Wasaburo Taniguchi, a farmer, rediscovered the mine, and Mr. Nakamura and Mr. Tatsuta ran the mine by the name of Naka-Tatsu mine.
- 1894: Began to mine silver.
- 1895: Closed.
- 1904: Began to mine zinc as Fukazawa mine.
- 1934: Nihon zinc mining corporation started to mine commercially.
- 1944: Temporary closed.
- 1951: Restarted to mine. Produced 150 ton ore per a day.
- 1956: Akaiwa deposit was found.
- 1987: Closed because of high yen-dollar rate.
Localities
- Horado Mine (Zn-Co)
- Komoto Mine (Magnetite)
- Kawai Mine (Fe-rich)
- Nakatatsu Mine (Zn)
- Ogibira Mine (Arsenate)