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Goyasu Formation (Nakamura, 1913) Kamata, 1972

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

• Sedimentary facies: Marine
• Sedimentary facies (Upper): Inner shelf
• Sedimentary facies (Lower): Upper shoreface - Lower shoreface
• Lithofacies (Upper): Sandstone
• Lithofacies (Middle): Sandstone
• Lithofacies (Lower): Gravelly sandstone
• Lithofacies (Basal): Conglomerate
• Lithofacies (Minor): Coal
• Sedimentary structures: Bioturbation
• Sedimentary structures (Lower): Cross stratification

• Thickness: 20 - 150 m
• Upper limit: Bottom of the mudstone bed overlying the sandstone bed
• Upper limit: Transitional (Mizunoya Formation), Unconformity (Mukaiyama Formation)
• Upper limit (West): Unconformity (Yoshinoya Formation)
• Lower limit: Conformity (Kunugidaira Formation), Unconformity (Shirasaka Formation, Gozaisho Metamorphic Rocks)

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

• Distribution: Goyasu, Jobanmatsukusune town, Iwaki city, Fukushima pref.; Yamadorisaku, Haramachi ward, Minamisoma city, Fukushima pref.; Kawabusa river, Kitanouchi - Higashihata, Odaka ward, Minamisoma city, Fukushima pref.; Suenomori, Namie city, Futaba county, Fukushima pref.; Hanyasawa, Tomioka city, Futaba county, Fukushima pref.; Suetsugi, Hisanohama town, Iwaki city, Fukushima pref.; Shibahara, Ogawa town, Iwaki city, Fukushima pref.
• Fossils (Shellfishes): Dentalium sp., Euspira sp., Glycymeris cf. cisshuensis, Lucinoma kamenooensis, Macoma sp., Mytilus tichanovitchi, Ostrea sp., Spisula sp., Turritella sp.
• Fossils (Trace fossils): Thalassinoides isp.

• 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.)