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Nagareya Formation Okamoto et al., 2003

It had been included in Upper Yezo Group.

• Coherent formation
• Yezo forearc basin
• Cretaceous, Campanian (Ammonoids)

• Sedimentary facies: Marine
• Lithofacies (Upper): Siltstone
• Lithofacies (Middle, Main): Siltstone, Silty sandstone
• Lithofacies (Middle, Minor): Sandstone
• Lithofacies (Lower, Main): Siltstone, Silty sandstone
• Lithofacies (Lower, Minor): Sandstone
• Lithofacies (Bottom): Silty sandstone

• Thickness: ca. 400 m
• Upper limit: Unconformity
• Lower limit: Lithofacies boundary (The boundary between coarse sandstone and upper silty sandstone)

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

• Distribution: Miginosawa creek, Haboro river, Haboro city, Tomamae county, Hokkaido
• Fossils (Ammonoids): Neophylloceras ramosum, Phyllopachyceras ezense, Anagaudryceras yokoyamai, Gaudryceras tenuiliratum, Tetragonites glabrus, Hyphantoceras cf. heteromorphum, Eubostrychoceras sp., Polyptychoceras yubarense, Polyptychoceras haradai, Polyptychoceras cf. pseudogaultinum, Hauericeras angustum, Eupachydiscus haradai, Yokoyamoceras ishikawai, Texanites? sp., Platyceramus japonicus, Platyceramus ezoensis, Naefia matsumotoi

• Kawabe and Okamoto (2012) Jour. Geol. Soc. Japan, vol.118, no.12, pp.769-781 DOI