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Mizunoya Formation (Nakamura, 1913) Tokunaga, 1927

• Type locality: Jobanmizunoya town, Iwaki city, Fukushima prefecture
• Coherent formation
• southern Yezo Forearc basin (Jobanoki basin)
• early Miocene (Diatoms)

• Sedimentary facies: Marine
• Sedimentary facies: Outer shelf - Upper continental slope
• Lithofacies (Upper): Interbedded sandy siltstone and sandstone, Turbidite
• Lithofacies (Lower): Sandy siltstone
• Sedimentary structures (Upper): Graded bedding

• Thickness: ca. 20 - 150 m
• Thickness (Upper): ca. 40 - 60 m
• Thickness (Lower): ca. 50 m or thinner
• Upper limit: Conformity (Kamenoo Formation), Unconformity (Yoshinoya Formation, Mukaiyama Formation, Minamishirado Formation)
• Lower limit: Bottom of the mudstone bed overlying the sandstone bed
• Lower limit: Transitional (Goyasu Formation)

------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

• Distribution: Jobanmizunoya town, Iwaki city, Fukushima pref.; Shimohara, Odaka ward, Minamisoma city, Fukushima pref.; Murohara - Suenomori, Namie city, Futaba county, Fukushima pref.; Tateishi, Naraha city, Futaba county, Fukushima pref.; Suetsugi, Hisanohama town, Iwaki city, Fukushima pref.; Yotsunami - Mount Ishimori - Shimoyoshima, Iwaki city, Fukushima pref.; Futaba city - Hirono city, Futaba county, Fukushima pref.
• Fossils: Crabs (Thyasira bisecta), Radiolarians
• Fossils (Shellfishes): Dentalium sp., Lucinoma sp., Teredo sp.
• Fossils (Diatoms): Actinocyclus cf. ingens, Actinocyclus octonarius, Actinoptychus senarius, Actinoptychus splendens, Adoneis pacifica, Aulacosira spp., Azpeitia endoi, Cocconeis californica, Coscinodiscus lewisianus, Coscinodiscus marginatus, Hemiaulus bipons, Ikebea tenuis, Kisseleviella carina, Paralia sulcata, Rhizosolenia styliformis, Stellarima sp., Stephanogonia hanzawae, Stephanopyxis spp., Thalassionema nitzschioides, Thalassiothrix longissima

• Ando et al. (2011) Jour. Geol. Soc. Japan, vol.117, Supplement, pp.49-67 DOI
• Kubo et al. (2002) Geology of the Kawamae and Ide District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 136p. (in Japanese with English abstract 6p.)
• Kubo et al. (1994) Geology of the Namie and Iwaki-Tomioka District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 104p. (in Japanese with English abstract 7p.)
• Kubo et al. (1990) Geology of the Haramachi and Omika District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 138p. (in Japanese with English abstract 7p.)
• Kano et al. (1973) Geology of the Takanuki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 109p. (in Japanese with English abstract 6p.)
• Iwao and Matsui (1961) Taira and Kawamae, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 103p. (in Japanese with English abstract 17p.)