Kiura Mine
Kiura-Kozan, Ume, Saiki city, Oita pref., Japan
Occurrence
Skarn formed by the middle Miocene (14 Ma) Okueyama Granite intruded in the early Paleocene (65 Ma) Sambosan unit, a member of the Southern Chichibu accretionary complex. The pneumatolytic deposit associated with the skarn was formed by the ring dike of granite porphyry and quartz porphyry. The Okueyama Granite is I-type (Magnetite-series), and approximately 5 km apart from this locality. The sulfide depostis are in contact with the ring dike. The protolith of the skarn is Middle Triassic (240 Ma) reef limestone. The Okueyama Granite and the ring dike are considered as members of the Miocene Okueyama Caldera Complex, and the Okueyama Granite is the center pluton of the caldera complex. Ages of sedimentary rocks were determined by radiolarians, limestone by microfossils, and igneous rocks by K-Ar radiometric dating of biotite and Rb-Sr isochron age.
Outcrop of oxidation zone associated with skarn of the Wando deposit in the Sambosan Unit. The white part is crystalline limestone (Calcite), and cracks were filled with brown limonite. The surrounding massive gray parts are fine-grained crystalline limestone. Limonite was formed by weathering of iron sulfides in the deposit. Secondary minerals such as hemimorphite were recovered from open spaces of limonite.
Reported Minerals
- Calcite
- Parasymplesite
- Arsenopyrite
- Fluorite
- Corundum (Emery)
- Margarite
- Scarbroite
- Wollastonite
- Hemimorphite
- Casiterite
- Löllingite(Lollingite)
- Schneiderhöhnite(Schneiderhohnite)
- Vesuvianite
- Hedenbergite
- Hedleyite
- Diopside
- Scorodite
- Karibibite
- Bismuth
- Tetrahedrite
- Scheelite
- Tyrolite
- Clinoclase
- Conichalcite
- Pharmacosiderite
- Magnetite
Mineral Assemblages
- Limonite - Hemimorphite - Calcite
- Corundum - Margarite
- Quartz - Lollingite - Scorodite
- Quartz - Lollingite - Parasymplesite
Details of the mine
Emery was mined.
Localities
- Kamioka Mine (Pb-Zn)
- Kiura Mine (Emery)
- Toroku Mine (Arsenate)
- Obira Mine (Granite porphyry)
- Hoei Mine (Granite porphyry)