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Yumoto Formation Iwai, 1949

• Type locality: Rairai valley, Yumoto, Akiu town, Taihaku ward, Sendai city, Miyagi prefecture
• Coherent formation
• late Miocene (17.5, 17.1 Ma, FT)
• Intruded by: Andesite

• Sedimentary facies: Pyroclastic flow deposit
• Lithofacies: Pumice tuff
• Lithofacies (Minor): Tuff breccia, Lapilli tuff

• Thickness: ca. 100 - 200 m
• Upper limit: Unconformity (Nashino Formation)
• Lower limit: Unconformity (Takadate Formation, Moniwa Formation, Hatatate Formation, Tsunaki Formation)

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

• Distribution: Rairai valley, Yumoto, Akiu town, Taihaku ward, Sendai city, Miyagi pref.; Lake Gassan, Kamiaishi, Aoba ward, Sendai city, Miyagi pref.
• Fossils: Silicified woods, Carbonized woods

• Miyamoto et al. (2013) Jour. Geol. Soc. Japan, vol.119, Supplement, pp.27-46 DOI
• Kitamura et al. (1986) Geology of the Sendai District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 134p. (in Japanese with English abstract 9p.)