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Volcanic Fan 1 Deposit

• Volcanic rocks
• Pleistocene (ca. 15 ka)
• Contemporaneous heterotopic facies: Younger volcanic-cone-building stage

• Sedimentary facies: Terrestrial
• Lithofacies: Debris flow deposit, Hyperconcentrated flood flow
• Lithofacies: Andesite, Dacite gravels, Sands
• Sedimentary structures: Parallel stratification, Graded bedding, Reversed graded bedding

• Thickness: 100 m or thicker
• Upper limit: Conformity (Itoi Pumice Flow Deposit, Fudo Pumice Flow Deposit), partly unconformity (Fujiki Pumice Flow Deposit), Unconformity (Volcanic Fan 2 Deposit)
• Lower limit: Conformity, Unconformity (Nashiki Debris Avalanche Deposit)

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

• Distribution: The foot of Mount Akagi except the north-eastern foot, Gunma pref.

• Ito et al. (2022) Geology of the Kiryu and Ashikaga District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 101p. (in Japanese with English abstract 4p.)
• Yamamoto (2016) Jour. Geol. Soc. Japan, vol.122, no.3, pp.109-126, DOI