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Hirasawatsudani Formation Ishida, 2007

• Type locality: Hirasawatsudani, Shimanto town, Yatsushiro city, Kumamoto prefecture
• Type locality (Upper): Upper reaches of Hirasawatsudani, Shimanto town, Yatsushiro city, Kumamoto prefecture
• Type locality (Lower): Hirasawatsudani, Shiiba, Shimanto town, Yatsushiro city, Kumamoto prefecture
• Accretionary complex
• Deposition: Early Jurassic, Hettangian (Radiolarians)
• Correlation: Sakamoto Formation

• Sedimentary facies: Marine
• Sedimentary facies: Continental shelf
• Sedimentary facies: Turbidite
• Lithofacies (Upper): Mudstone
• Lithofacies (Upper, Minor): Sandstone
• Lithofacies (Lower): Sandstone
• Lithofacies (Lower, Minor): Conglomerate, Interbedded sandstone and mudstone
• Sedimentary structures (Upper): Parallel stratification, Current ripples

• Thickness (Upper): 100 m or less
• Thickness (Lower): 35 - 45 m
• Upper limit: Fault
• Lower limit: Parallel unconformity (Matsukuma Formation)

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

• Distribution: Iiboshi river - Hirasawatsudani, Shimanto town, Yatsushiro city, Kumamoto pref.
• Fossils (Upper, Radiolarians): Droltus sp., Trexus? sp., Canoptum spp., Natoba? sp., Protokatroma sp., Pseudoeucyrtis? sp., Archaeocenosphaera? sp., Pantanellium cf. blowni, Pantanellium cf. tanuense, Pantanellium cf. kluense, Orbiculiforma? spp., Paromaella? sp., Nassellaria gen. et sp. indet
• Fossils (Lower, Radiolarians): Natoba sp., Archaeocenosphaera? sp., Nassellaria gen. et sp. indet

• Ishida (2015) Jour. Geol. Soc. Japan, vol.121, no.2, pp.45-58 DOI
• Ishida (2007) Jour. Geol. Soc. Japan, vol.113, no.3, pp.83-94 DOI