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Tomoda Formation Ueki and Sakai, 2007

Invalid synonym: Ashigeta Formation

• Type locality: Chigase town - Kabe town, Ome city, Tokyo
• Coherent formation
• late Pliocene (2.9 - 2.6 Ma, Tephra, Paleomagnetism)

• Sedimentary facies: Fluvial
• Lithofacies: Interbedded silt and sands
• Lithofacies (Minor): Pumiceous tephra, Vitreous tephra, Lignite
• Lithofacies (Bottom): Breccia
• Sedimentary structures (Bottom): Channel structure

• Thickness: ca. 40 m
• Upper limit: Unconformity (Onita Formation)
• Lower limit: Unconformity (Raidenyama Unit, Minokuchi Unit, Akikawa Formation)

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

• Distribution: Chigase town - Kabe town - Nagabuchi - Tomoda town - Mabikizawa pass, Ome city, Tokyo; Ashigeta - Hirai river, Hirai, Hinode city, Nishitama county, Tokyo; Futatsuzuka pass, Oguno, Hinode city, Nishitama county, Tokyo; Sugao, Akiruno city, Tokyo
• Fossils: Elephants (Stegodon? sp.), Insects, Diatoms
• Fossils (Plants): Juglans megacinerea, Metasequoia disticha (Taxodioxylon sequoianum, Metasequoia cfr. glyptostroboides), Sequoia sp.
• Fossils (Pollen): Lagerstroemia sp., Metasequoia japonica
• Tephra: CGS 1, CGS 2, CGS 3, CGS 4, CGS 5, CGS 6, TMD 1, TMD 2, TMD 3, TMD 4, TMD 5, TMD 6, TMD 7, TMD 8

• 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.)