Shichikosan Lava

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Shichikosan Lava Hayashi, 1984

Stratovolcano
Volcanic rocks
Holocene

Lithofacies: Olivine hypersthene augite andesite, Hypersthene augite andesite
Lithofacies: Lava (more than 24 flow units), Agglutinates

Eruptive volume: 2.82 km³
Thickness: 200 m or thicker
Lower limit: Unconformity (Upper Kanomatagawa Lava, Shirasawagawa Lava)

Stage IIIa
[ Upper ]
~~~~~~~~~~~~~~
Saruana Lava
~~~~~~~~~~~~~~
[ Lower ]

Stage IIIa
[ Upper ]
~~~~~~~~~~~~~~
Nabemori Lava
~~~~~~~~~~~~~~
Mansukemichi Lava
~~~~~~~~~~~~~~
[ Lower ]

Stage IIIa
[ Upper ]
~~~~~~~~~~~~~~
Shichikosan Lava
~~~~~~~~~~~~~~
[ Lower ]

Stage III
[ Upper ]
+__+__+__+__+_
Stage IIIb
~~~~~~~~~~~~~~
Kisakata Debris Avalanche Deposit
~~~~~~~~~~~~~~
Stage IIIa
~~~~~~~~~~~~~~
[ Lower ]

Chokai volcano
[ Upper ]
+__+__+__+__+_
Stage III
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Stage II
~~~~~~~~~~~~~~
Stage I
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Mount Shichiko, Yurihonjo city, Akita pref.; Akagawa river, Kisakata, Nikaho city, Akita pref.

Hayashi and Yamamoto (2008) Jour. Geol. Soc. Japan, vol.114, Supplement, pp.87-95 DOI
Nakano and Tsuchiya (1992) Geology of the Chokaisan and Fukura District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 138p. (in Japanese with English abstract 7p.)