Gongenzaki Formation

Type locality: Cape Gongen, Kodomari, Nakadomari city, Kitatsugaru county, Aomori prefecture
Volcanic rocks
early Miocene (23.0 - 20.0 Ma, FT)

Sedimentary facies: Terrestrial
Lithofacies (Upper): Andesitic tuff breccia, Lapilli tuff
Lithofacies (Lower): Andesitic tuff, Tuff breccia
Lithofacies (Lower, Minor): Altered andesite lava
Lithofacies (Bottom): Basal conglomerate

Thickness: 100 - 500 m
Thickness (Upper): ca. 350 m
Thickness (Lower): ca. 200 m
Upper limit: Abut unconformity (Isomatsu Formation)
Lower limit: Unconformity

Gongenzaki Formation (Minmaya)
[ Upper ]
~~~~~~~~~~~~~~
Variegated Tuff Member
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Purple Propylite Member
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Purple Tuff Breccia Member
~~~~~~~~~~~~~~
[ Lower ]

Northern Tsugaru peninsula
[ Upper ]
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Nagane Formation
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Fuyube Formation
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Isomatsu Formation
~~~~~~~~~~~~~~
Gongenzaki Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Cape Gongen, Kodomari, Nakadomari city, Kitatsugaru county, Aomori pref.; Koyobi creek - Katakariishi creek, Isomatsu river, Kodomari, Nakadomari city, Kitatsugaru county, Aomori pref.; Mount Yotsudaki, Shiura, Koshogawara city, Aomori pref.
Fossils (Aniai-type flora?): Plants

Hoshi et al. (2016) Jour. Geol. Soc. Japan, vol.122, no.4, pp.163-170, DOI
Kamikuri et al. (2010) Jour. Geol. Soc. Japan, vol.116, no.8, pp.403-411 DOI
Tsushima and Uemura (1959) Kodomari, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 45p. (in Japanese with English abstract 5p.)
Ota et al. (1957) Mimmaya, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 30p. (in Japanese with English abstract 5p.)