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Okunoin volcano

• Type locality: Southern cliff of Okunoin, Otaki city, Kiso county, Nagano prefecture
• Volcanic rocks
• Stratovolcano
• late Pleistocene (ca. 59 ka, K-Ar)

• Sedimentary facies (Minor): Scoria hill
• Lithofacies: Augite hypersthene andesite
• Lithofacies (Minor): Hypersthene hornblende andesite, Hornblende/Olivine-bearing aAugite hypersthene andesite
• Lithofacies: Scoria agglomerate, Lava, Pyroclastic flow deposit
• Lithofacies (Minor): Lava, Pyroclastic surge deposit

• Source: Okunoin, Mount Ontakeyama
• Thickness: ca. 20 - 100 m
• Upper limit: Unconformity (Ichinoike volcano)
• Lower limit: Unconformity (Kongodo volcano, Takigoshi Formation, Mamahahadake volcano group)

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

• Distribution: Okunoin - Shimokurosawa creek - Denjogawa river - Akagawa river - Nigorikawa river - Takigoshi - Otakigawa river - Suzugsawa creek, Otaki city, Kiso county, Nagano pref.

• Takeuchi et al. (1998) Geology of the Kiso-Fukushima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 94p. (in Japanese with English abstract 4p.)
• Yamada and Kobayashi (1988) Geology of the Ontakesan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 136p. (in Japanese with English abstract 9p.)