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Oshio Pyroclastic Flow Deposit Kato et al., 1989

Different geological unit from Oshio Pyroclastic Flow Deposit (Kawachi et al., 1967) in Chino area, Nagano pref.

Invalid synonym: Yashiro Tuff and Conglomerate Member, Yashiro Conglomerate and Tuff Member

• Type locality: Oshio - Miyanowaki, Miasa, Omachi city, Nagano prefecture
• Tephra
• Pliocene (2.4, 2.0 Ma, K-Ar)

• Lithofacies: Biotite rhyolite volcanic ash flow depsoit
• Lithofacies (Minor): Conglomerate, Sandstone, Mudstone, Coal
• Sedimentary structures (Minor): Cross stratification

• Thickness: 200 - 800 m or thicker
• Upper limit: Conformity (Hino Member), Unconformity (Shingyo Gravel Deposits, Omachi Tephra)
• Lower limit: Unconformity (Miasa Formation, Taroyama Andesite)

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

• Distribution: Oshio - Miyanowaki - Mount Gongenyama - Aikawa - Jokoji - Odaira, Omachi city, Nagano pref.
• Fossils: Shellfishes (Anodonta sp.), Plants (Metasequoia sp., Salix sp.)

• Kato et al. (1989) Geology of the Omachi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 111p. (in Japanese with English abstract 7p.)
• Kato and Sato (1983) Geology of the Shinano-Ikeda District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 93p. (in Japanese with English abstract 7p.)