Kohamadatezawa Andesite Member

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Kohamadatezawa Andesite Member Hirayama and Uemura, 1985 (Photo)

Invalid synonym: Ogitazawa Andesite

Host of bedded Mn deposits

Type locality: middle - upper reaches of Kohamadate creek, Fukaura city, Nishitsugaru county, Aomori prefecture
Volcanic rocks
middle Miocene

Sedimentary facies: Fluvial
Sedimentary facies: Transgressive
Lithofacies: Andesite lava, Tuff breccia, Lapilli tuff
Lithofacies (Minor): Scoria tuff, Conglomerate, Rhyolitic - dacitic pyroclastic rocks, Lava

Thickness: 100 - 500 m
Upper limit: Unconformity (Tanosawa Formation)
Lower limit: Conformity (Azumagawa Rhyolite Member)

Otose Formation
[ Upper ]
~~~~~~~~~~~~~~
Kohamadatezawa Andesite Member
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Azumagawa Rhyolite Member
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Kiyotakizawa Andesite Member
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[ Lower ]

Fukaura, Aomori pref.
[ Upper ]
~~~~~~~~~~~~~~
Narusawa Formation
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Maito Formation
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Akaishi Formation
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Odoji Formation
-------~~~~~~~
Tanosawa Formation
~~~~~~~~~~~~~~
Otose Formation
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Fujikuragawa Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Kohamadate creek, Fukaura city, Nishitsugaru county, Aomori pref.; Cape Torii - Cape Shiomi, Fukaura city, Nishitsugaru county, Aomori pref.; Mount Masugata, Fukaura city, Nishitsugaru county, Aomori pref.; Mount Takaniu, Fukaura city, Nishitsugaru county, Aomori pref.

Hirayama and Uemura (1985) Geology of the Ajigasawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 86p. (in Japanese with English abstract 6p.)