Tungsten quartz veins of the Otani mine, Kyoto The Otani mine, one of the largest tungsten mines in Japan mined until 1983, is composed of scheelite-chalcopyrite-pyrrhotite-quartz veins filling NNE fractures formed by right-lateral shearing in late Cretaceous biotite granodiorite with 98.9 Ma Rb-Sr age. The sulfides of the host granodiorite and ore veins have negative δ34S values indicating a sedimentary biogenic source(see p. 461 - 477 in the text). This picture is taken at the Chuo Adit Level of No.2 Vein at north mining face of August. 1980. “Greisenization”was seen along the granodiorite contact. |