Obonai Pyroclastic Flow Deposit

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Obonai Pyroclastic Flow Deposit (Inoue, 1979) Suto, 1982

Type locality: Hinokinai river, Obonai, Tazawako, Senboku city, Akita prefecture
Tephra
Pleistocene (12.4, 13.0, 13.4 ka, ¹⁴C)

Lithofacies: Volcanic tuff
Lithofacies (Minor): Charcoal

Thickness: 3 - 6 m

.Syn-caldera formation stage
[ Upper ]
~~~~~~~~~~~~~~
Yanagisawa Pumice Deposit
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Obonai Pyroclastic Flow Deposit
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Koiwai Pumice Deposit
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[ Lower ]

Akita-Komagatake volcano
[ Upper ]
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Post-caldera eruption stage
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Syn-caldera formation stage
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Main strato cone stage
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[ Lower ]

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

Distribution: Hinokinai river - Takano farm - Owada creek, Obonai, Tazawako, Senboku city, Akita pref.; Kunimi hot spring, Shizukuishi city, Iwate county, Iwate pref.

Suto and Ishii (1987) Geology of the Shizukuishi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 142p. (in Japanese with English abstract 5p.)