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Okogawazawa Debris Flow Deposit (Takarada et al., 1998) Takarada and Muraoka, 2004

Invalid synonym: Okogawazawa Formation

• Type locality: 690 m above sea level of Okogawa creek, Kuroishi city, Aomori prefecture
• Pre-caldera volcanoes
• Coherent formation
• Pleistocene (ca. 0.8 - 0.5 Ma)

• Sedimentary facies: Lahar
• Lithofacies: Debris flow deposit
• Lithofacies: Conglomerate (more than tens flow units)
• Lithofacies (Minor): Scoria flow deposit, Scoria fall deposit

• Source: Mount Shimodake, Mount Kushigadake, Mount Minamizawa, Mount Yokodake
• Thickness: ca. 100 m
• Thickness (A unit): Tens cm - several m
• Upper limit: Unconformity (Hakkoda 2nd-stage Pyroclastic Flow Deposit, Minami-Hakkoda 2nd-stage Lava and Pyroclastic Rocks)
• Lower limit: Unconformity (Minami-Hakkoda 1st-stage Lava and Pyroclastic Rocks, , Aoni Tuff, Anamizuzawa Lithic Tuff Member)

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

• Distribution: Okogawa creek - Aoni river - Nakano river, Kuroishi city, Aomori pref.

• 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.)