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Towada-Ofudo Pyroclastic Flow Deposit (Tohoku Region Quaternary Research Group, 1969) Takarada and Muraoka, 2004

Abbr.: To-Of

Synonym.: Towada-Ofudo Tephra

Synonym (Invalid).: Ofudo Pumice Tuff, Ofudo ignimbrite, Fukuoka Pumice (a part), Fukuoka Formation (a part)

• Type locality: Ofudo, Towada city, Aomori prefecture
• Tephra
• Pleistocene (35.8 cal ka BP, ¹⁴C, 29.6 - 29.0 ka, ¹⁸O)

• Lithofacies: Un-welded pyroclastic flow deposit (2 - 3 flow units)
• Lithofacies: Rhyolitic pumice flow deposit
• Lithofacies (Pumice): Hornblende-deficient
• Sedimentary structures: Reversed graded bedding

• Thickness: 3 - 10 m
• Thickness (A sheet): several m
• Source: Towada caldera
• Upper limit: Unconformity (Towada-Hachinohe Pyroclastic Flow Deposit)
• Lower limit: Unconformity (Hakkoda 1st-stage Pyroclastic Flow Deposit, Towada-Okuse Pyroclastic Flow Deposit, Nakuidake Volcanic Rock Member)

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

• Distribution: Ofudo, Towada city, Aomori pref.; Nurukawa - Suginoki - Takinosawa pass - Sennosawa creek, Towada city, Aomori pref.; Hosono - Aizawa, Namioka, Aomori city, Aomori pref.; Iwatari - Kodate, Aomori city, Aomori pref.; Kosaka city, Kazuno county, Akita pref.; Hayawatari, Karumai city, Kunohe county, Iwate pref.; Nonoue - Jumonji - Uwasato - Aikawa, Ninohe city, Iwate pref.; Togariishi - Iwadate, Ichinohe city, Ninohe county, Iwate pref.

• Okuno (2019) Jour. Geol. Soc. Japan, vol.125, no.1, pp.41-53 DOI
• Tuzino et al. (2018) Geology of the Ichinohe District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 161p. (in Japanese with English abstract 4p.)
• Nagamori et al. (2013) Geology of the Aomori-Seibu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 67p. (in Japanese with English abstract 4p.)
• Kudo (2005) Geology of the Towada District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 79p. (in Japanese with English abstract 3p.)
• Takarada and Muraoka (2004) Geology of the Hakkoda San District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 86p. (in Japanese with English abstract 4p.)