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Uragawara Formation Takeuchi and Kato, 1994

Invalid synonym: Nagasaka Formation, Tsuitachi Formation

• Type locality: Hokura river, Uragawara, Joetsu city, Niigata prefecture
• Coherent formation
• late Pliocene
• Correlation (Upper): lower Naradate Formation
• Correlation (Lower): Shiroiwa Formation

• Sedimentary facies: Shallow marine
• Lithofacies: Sandstone, Interbedded sandy siltstone and siltstone
• Lithofacies (Upper, Minor): Conglomerate, Acidic tuff
• Sedimentary structures: Ripple marks
• Paleocurrent: Southwest to Northeast

• Thickness: 250 - 750 m or thicker
• Lower limit: Conformity (Tamugigawa Formation)

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

• Distribution: Hokura river - Hishida - Takatani river, Uragawara, Joetsu city, Niigata pref.
• Fossils: Trace fossils (Tube form), Foraminifera
• Tephra: Nagashiri Tuff

• Takeuchi et al. (1996) Geology of the Kakizaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 48p. (in Japanese with English abstract 5p.)
• Takeuchi and Kato (1994) Geology of the Takada-tobu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 67p. (in Japanese with English abstract 5p.)