Post-caldera stage

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Post-caldera stage

Invalid synonym: Younger Oshima Group

Type locality: Oshima city, Tokyo
Volcanic rocks
Stratovolcano, Caldera volcano
Holocene (1,300 yBP, ¹⁴C or later)

Sedimentary facies: Scoria cone, Lava
Lithofacies: Low-alkaline tholeiite series
Lithofacies: Pigeonite series
Lithofacies: Pyroxene basalt, Olivine basalt

Eruptive volume (Younger Oshima Group): 3.6 km³
Lower limit: Unconformity (Older edifice)

Post-caldera stage
[ Upper ]
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Izu-Oshima 2013 Lahar Deposit
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1954 Lava
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1950 Lava
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[ Lower ]

Post-caldera stage
[ Upper ]
~~~~~~~~~~~~~~
Yuba Formation
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Nomashi Formation
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[ Lower ]

Oshima volcano
[ Upper ]
~~~~~~~~~~~~~~
Post-caldera stage
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Syn-caldera stage
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Pre-caldera stage
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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.)