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Hashimoto Formation (Shiraishi, 1982) Osawa et al., 1985

Invalid synonym: Hashimoto Terrace Deposit

• Type locality: Hashimoto seashore - Miyazawa seashore, Oga city, Akita prefecture
• Coherent formation
• Holocene (6,320, 4,560 yBP, ¹⁴C)
• Contemporaneous heterotopic facies: Older Dune of Noshiro Coastal Dune
• Correlation: Jomon transgression

• Climate: Warm (Pollen)
• Lithofacies (Upper): Sands, Gravels
• Lithofacies (Lower): Sands
• Lithofacies (Minor): Mud, Peat

• Thickness: 2 - 5 m
• Lower limit: Unconformity (Tentokuji Formation, Katanishi Formation, Kitaura Formation)

• Distribution: Hashimoto terrace, Oga city, Akita pref.; Hashimoto seashore - Miyazawa seashore, Oga city, Akita pref.
• Fossils (Pollen, Deciduous trees): Carpinus sp., Cryptomeria sp., Fagus sp., Fraxinus sp., Gramineae sp., Juglance sp., Quercus sp.

• Kano et al. (2011) Geology of the Toga and Funakawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 127p. (in Japanese with English abstract 4p.)
• Shiraishi et al. (2008) Jour. Geol. Soc. Japan, vol.114, Supplement, pp.33-50 DOI
• Fujimoto et al. (2008) Jour. Geol. Soc. Japan, vol.114, Supplement, pp.51-74 DOI
• Ozawa et al. (1985) Geology of the Ugo-Hamada District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 57p. (in Japanese with English abstract 4p.)