Morikuma Volcanic Breccia Member

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Morikuma Volcanic Breccia Member Akima Collaborative Research Group, 1971

Volcanic rocks
Pliocene

Sedimentary facies: Pyroclastic flow deposit, Debris flow deposit, Debris avalanche deposit
Lithofacies: Tholeiite, Calc-alkaline
Lithofacies: Andesite volcanic breccia, Tuff breccia
Lithofacies (Minor): Tuffaceous sandstone, Tuff, Tuffaceous siltstone
Lithofacies (Bottom): Tuffaceous sandstone, Tuff breccia

Thickness (Pyroclastic flow deposit): ca. 20 m
Thickness (Debris avalanche deposit): ca. 20 m

Akima Formation
[ Upper ]
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Upper part
~~~~~~~~~~~~~~
Chausuyama Welded Tuff Member
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Otogai Tuff Breccia Member
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Nagaiwa Lapilli Tuff Member
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Morikuma Volcanic Breccia Member
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[ Lower ]

Kirizumi volcano
[ Upper ]
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Aimagawa Formation / Akima Formation
~~~~~~~~~~~~~~
[ Lower ]

Takasaki Group
[ Upper ]
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Akima Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Gunma pref.

Geshi and Takeuchi (2012) Geology of the Haruna San District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 79p. (in Japanese with English abstract 3p.)