Oshima volcano

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Oshima volcano

Synonym: Izu-Oshima volcano

Type locality: Oshima city, Tokyo
Volcanic rocks
Stratovolcano, Caldera volcano
late Pleistocene - Holocene (older than 41,600 yBP, ¹⁴C)

Lithofacies: Low-alkaline tholeiite series
Lithofacies: Olivine basalt, Pyroxene olivine basalt lava, Pyroclastic flow deposit
Lithofacies (Minor): Pyroxene andesite lava, Pyroxene dacite pumic fall deposit

Distribution (Caldera, Length): 4.5 km
Distribution (Caldera, Width): 3.5 km
Lower limit: Unconformity (Okata volcano, Fudeshima volcano, Gyojanoiwayam volcano)

Oshima volcano
[ Upper ]
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Post-caldera stage
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Syn-caldera stage
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Pre-caldera stage
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[ Lower ]

Oshima volcano
[ Upper ]
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Lateral volcanoes
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[ Lower ]

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

Distribution: Oshima city, Tokyo

Isshiki (1984) Geology of the Oshima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 133p. (in Japanese with English abstract 5p.)