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Yoshinazawa Formation Shiraishi, 1992

• Type locality: Odokorogawa river - Yoshinazawa creek, Kotaki, Itoigawa city, Niigata prefecture
• Coherent formation
• Jurassic
• Correlation: Negoya Formation

• Sedimentary facies: Fluvial
• Lithofacies: Sandstone
• Lithofacies (Minor): Interbedded mudstone and sandstone
• Sedimentary structures: Cross-stratification, Channel structures

• Thickness: ca. 400 - 1,000 m
• Lower limit: Conformity (Bottom of the thick sandstone bed)
• Lower limit: Conformity (Odokorogawa Formation)

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

• Distribution: Odokorogawa river - Yoshinazawa creek - Kotakigawa river - Shikkuizawa creek - Mount Nakamatayama, Kotaki, Itoigawa city, Niigata pref.; Tsunzawa - Kuruma - Urakawa river, Otari city, Kitaazumi county, Nagano pref.
• Fossils: Dinosaur (Footprints)
• Fossils (Shellfishes): Bakevellia otariensis, Cardinoides varidus, Corbicula kurumaensis, Mytilus heranirus

• Takeuchi et al. (2017) Jour. Geol. Soc. Japan, vol.123, no.5, pp.335-350 DOI
• Takeuchi et al. (2015) Jour. Geol. Soc. Japan, vol.121, no.7, pp.193-216, DOI
• Nagamori et al. (2010) Geology of the Kotaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 130p. (in Japanese with English abstract 4p.)
• Nakano et al. (2002) Geology of the Shiroumadake District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 105p. (in Japanese with English abstract 5p.)