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Hanno Formation Hanno City, 1986

Invalid synonym: Azuyama Formation, Kobushi Formation

• Type locality: Azu, Hanno city, Saitama prefecture
• Coherent formation
• Pliocene
• Correlation: Nihondake Formation, Tomioka Formation, Oyabe Formation?, Terada Formation?, Hirayama Formation?

• Sedimentary facies: Fluvial
• Paleo-river system: Arakawa river or Tamagawa river
• Lithofacies: Gravels
• Lithofacies (Minor): Tuffaceous silt, Sands, Pumiceous tephra
• Sedimentary structures: Channel structure, Imbricate structure
• Paleocurrent: to East

• Thickness: ca. 100 m
• Upper limit: Conformity (Bushi Formation, Kasumi Formation)
• Lower limit: Unconformity (Nakato Unit, Nitayama Unit, Nariki Unit, Raidenyama Unit, Osoki Formation)

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

• Distribution: Azu - Yaoroshi - Iwasawa, Hanno city, Saitama pref.; Minamimine - Teratake, Iruma city, Saitama pref.; Nekabu - Osoki, Ome city, Tokyo
• Fossils (Pollen): Measequoia? sp.
• Tephra: Yaoroshi Tuff

• Ueki and Sakai (2007) Geology of the Ome District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 189p. (in Japanese with English abstract 5p.)