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Toyajo Formation

• Coherent formation
• Late Cretaceous, Campanian
• Contemporaneous heterotopic facies: upper Futakawa Formation

• Lithofacies (Top): Sandstone, Interbedded sandstone and mudstone
• Lithofacies (Upper): Silty sandstone
• Lithofacies (Upper, Minor): Sandy siltstone, Sandstone, Pipe rocks
• Lithofacies (Lower): Sandy silt
• Lithofacies (Lower, Minor): Silty sandstone

• Thickness: 1,100 m or thicker
• Thickness (Top): 130 m or thicker
• Thickness (Upper): ca. 600 m
• Thickness (Lower): 400 m or thicker
• Lower limit: Unconformity (Kurosegawa Belt)

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

• Distribution: Aridagawa river, Aridagawa city, Arida county, Wakayama pref.
• Fossils: Echinoids (Micraster sp.)
• Fossils (Ammonoids): Baculites sp., Bostrychoceras awajiense, Bostrychoceras japonicum, Epigoniceras cf. cala, Gaudryceras tenuiliratum, Hauericeras gardeni, Polyptychoceras sp., Pravitoceras sigmoidale, Pseudoperissites cf. bicarinata, Solenoceras sp.
• Fossils (Shellfishes): Aphrodina cf. pseudoplana, Ataphrus cf. teshioensis, Dentalium cf. cooperi var. ezoense, Exogyra sp., Grammatodon sachalinensis, Inoceramus balticus var. toyajoanus, Inoceramus schmidti, Lucina (Myrtea) ezoensis, Pecten (Propeamusium) cooperi var. yubarensis, Scurria cf. cassidarius

• Yao (2012) Jour. Geol. Soc. Japan, vol.118, Supplement, pp.90-106 DOI
• Hirayama and Tanaka (1956) Kainan, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 62p. (in Japanese with English abstract 12p.)