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Takizawagawa Formation (Hirabayashi, 1966) Yamamoto and Komazawa, 2004

Invalid synonym: Oshio Formation, Ogawazawa Formation, Otani Formation, Tamanashi Formation, Nishikata Formation

• Type locality: Takizawa river, Kaneyama city, Onuma county, Fukushima prefecture
• Volcanic rocks
• Lava domes
• early - middle Miocene (23?, 16, 15 Ma, K-Ar)
• Contemporaneous heterotopic facies: Higashiomata Formation
• Intruded by: Basalt dykes, Sills

• Sedimentary facies: Marine
• Sedimentary facies (Rhyolite): Gravity flow deposit, Submarine pyroclastic flow deposit
• Lithofacies: Rhyolite lava dome
• Lithofacies (Main): Lava, Volcanic breccia, Tuff breccia, Lapilli tuff, Volcanic sandstone, Tuff
• Lithofacies (Minor): Mudstone, Basalt
• Sedimentary structures: Graded bedding, Parallel stratification

• Distribution (Diameter, Lava dome): A few hundreds m - 2 km
• Thickness: 1,500 m
• Upper limit: Conformity (Fuzawa Formation), Unconformity (Shirifukitoge Pyroclastic Deposit, Uwaigusa Formation, Sunagohara Formation), Abut unconformity (Iriyamazawa Formation)

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

• Distribution: Takizawa river - Shirasawa river - Tadami river, Kaneyama city, Onuma county, Fukushima pref.; Tadami city, Minamiaizu county, Fukushima pref.; Hayato - Miyashita - Takiya, Mishima city, Onuma county, Fukushima pref.; Nishiaizu city, Yama county, Fukushima pref.

• Yamamoto and Hasebe (2014) Jour. Geol. Soc. Japan, vol.120, no.1, pp.1-9 DOI
• Masubuchi and Ishizaki (2011) Jour. Geol. Soc. Japan, vol.117, no.6, pp.357-376 DOI
• Yamamoto and Komazawa (2004) Geology of the Miyashita District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 71p. (in Japanese with English abstract 5p.)