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Bushi Formation Fujimoto, 1932

Invalid synonym: Iruma Formation

• Type locality: Azu, Hanno city - Bushi, Iruma city, Saitama prefecture
• Coherent formation
• late Pliocene - early Pleistocene
• Correlation: Hirayama Formation, Renkoji Formation, Umegase Formation, Kokumoto Formation, Oyabe Formation, Sayama Formation, Ozenji Formation, Kamihoshikawa Formation

• Sedimentary facies: Marine
• Sedimentary facies: Marsh, Mudflat, Inner bay
• Lithofacies: Silt, Sands
• Lithofacies (Minor): Lignite, Gravels
• Sedimentary structures: Channel structure

• Thickness: ca. 110 m
• Upper limit: Unconformity (Toyooka Formation)
• Lower limit: Conformity (Hanno Formation)

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

• Distribution: Azu, Hanno city, Saitama pref.; Bushi - Uekoyata, Iruma city, Saitama pref.; Iwasawa, Hanno city, Saitama pref.; Irumagawa river, Sasai, Sayama city, Saitama pref.
• Fossils: Stegodon aurorae, Deer, Insects (Plteumaris dorsata), Shellfishes, Foraminifera, Diatoms
• Fossils: Actinidia sp., Alnus japonica, Ampelopsis sp., Berchemia sp., Buxus sp., Carex sp., Ceratophyllum demersum, Cinnamomum macropodum, Clerodendron trichotomum, Cocculus trilobus, Cornus controversa, Cornus macrophylla, Corylopsis sp., Corylus sieboldiana, Cupressinoxylon sp., Cyclocarya paliurus, Fagara ailanthoides, Fagus sp., Ilex cornuta, Impatiens textori, Juglans megacinerea, Lindera? sp., Magnolia kobus, Metasequoia disticha (Taxodioxylon sequoianum), Nelumbo sp., Nuphar sp., Paliurus nipponicus, Phellodendron amurense, Picea koribai, Polygonum cf. hydropiper?, Potamogeton sp., Prenna sp., Prunus sp., Quercus serrata, Rhamnella sp., Rosaceae, Salix cf. integra, Sapium? sp., Scirpus sp., Sparganium sp., Stewartia monadelpha, Styrax japonica, Trapa maximowiczii, Viburnum sp., Vitis sp., Zanthoxylum piperitum, Zelkova serrata
• Fossils (Pollen): Carya sp., Cunninghamia sp., Glyptostroboides sp., Metasequoia sp., Pseudolarix sp.
• Fossils (Trace fossils): Footprints (Stegodon aurorae, Cetartiodactyla), Pipe rocks (Upogebia major, Ghost crab)
• Tephra: Kd44-Nk, E1
• Deposits: Lignite

• 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.)