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Ohyamashimo Formation Hayashi et al., 2017

Invalid synonym: Lower Formation

• Type locality: Sasayama river, Oyamashimo, Sasayama city, Hyogo prefecture
• Coherent formation
• Intermountain basin
• Early Cretaceous, Albian - ? (139, 136, 105.6 Ma, FT)

• Sedimentary facies: Fluvial
• Sedimentary facies: Meandering river
• Sedimentary facies: Gravelly fluvial, Sandy fluvial, Flood plain
• Lithofacies: Conglomerate, Sandstone, Mudstone
• Lithofacies (Basal): Conglomerate, Sandstone
• Lithofacies (Basal, Minor): Rhyolitic tuff (more than 3 sheets), Mudstone
• Sedimentary structures: Parallel stratification, Cross-stratification, Trace fossils

• Thickness: 1,300 m
• Upper limit: Litholofacies boundary (Appearance of andesitic pyroclastic rocks), Unconformity (Akusa Formation)
• Lower limit: Unconformity (Ajima Formation, Kaibara Formation, Kamitaki Formation)

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

• Distribution: Sasayama basin, Sasayama city, Hyogo pref.; Sasayama river, Kamitaki - Shimotaki, Tanba city, Hyogo pref.
• Fossils: Sauropods (Tambatitanis amicitiae), Mammals, Amphibians, Estherids, Ostracods (Mongolocypris sp., Eucypris sp.)
• Tephra: SSY-2 Tuff

• Hayashi et al. (2017) Jour. Geol. Soc. Japan, vol.123, no.9, pp.747-764 DOI
• Kobayashi and Goto (2008) Jour. Geol. Soc. Japan, vol.114, no.11, pp.577-586 DOI