Towada Nanbu Tephra

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Towada Nanbu Tephra (Nakagawa, 1963) Oike and Nakagawa, 1979

Abbr.: NB, Nb

Type locality: Aomori prefecture
Tephra
late Pleistocene (9.2 ka; 8.6, 8.3 year BP, ¹⁴C)

Lithofacies: Dacitic
Lithofacies (Kaimori Volcanic Ash Unit): Volcanic ash fall deposit
Lithofacies (Nanbu Pumice Unit): Pumice fall deposit

Source: Naknoumi lake of Towada caldera
Mode of eruption: Plinian
Thickness (Kaimori Volcanic Ash Unit): 3 m or thicker
Thickness: 50 cm
Lower limit: Conformity (Maisawa Terrace Deposit, Rendaino Terrace Deposit)

Towada Nanbu Tephra
[ Upper ]
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Kaimori Volcanic Ash Unit
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Nanbu Pumice Unit
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[ Lower ]

Towada Post-caldera Stage Tephra Group
[ Upper ]
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Towada-Chuseri Pyroclastic Fall Deposit
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Towada D' Tephra
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Towada Nanbu Tephra
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Towada Ninokura Tephra Group
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[ Lower ]

Towada caldera
[ Upper ]
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Towada Post-caldera Stage Tephra Group
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Towada Caldera-forming Stage Tephra Group
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[ Lower ]

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

Distribution: Kamikita plain, Aomori pref.
Distribution: Kokarumai, Karumai city, Kunohe county, Iwate pref.

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.)
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.)
Yoshida et al. (1987) Geology of the Rikuchu-Ono District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 70p. (in Japanese with English abstract 6p.)