Kunimitoge Formation

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Kunimitoge Formation Murai, 1962

Invalid synonym: Kunimi Formation, Horikizawa Formation

Type locality: Kunimi pass, Senboku city, Akita prefecture - Shizukuishi city, Iwate county, Iwate prefecture
Coherent formation Murai, 1962
Miocene (ca. 11 - 9 Ma, K-Ar)
Intrusive rocks: Miocene (ca. 8 - 6 Ma, K-Ar)

Lithofacies: Interbedded siltstone and tuff, Tuff
Lithofacies (Minor): Dolerite, Basalt lava, Hyaloclastite, Andesite, Dacite, Rhyolite lava, Tuff breccia

Thickness: ca. 1,000 m
Upper limit: Conformity (Ryukawa Formation), Unconformity (Ainaizawa Formation)
Lower limit: Conformity (Omata Formation), Unconformity (Obonai Formation)

Shizukuishi, Iwate pref.
[ Upper ]
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Kakkondagawa Pyroclastic Rocks
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Minamishirasawa Formation / Masuzawa Formation
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Yamatsuda Formation
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Koshitomaezawa Formation
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Ryukawa Formation
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Kunimitoge Formation
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Obonai Formation
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[ Lower ]

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

Distribution: Kunimi pass, Senboku city, Akita pref. - Shizukuishi city, Iwate county, Iwate pref.; western flank of Mount Akita-Komagatake, Akita pref.; Mount Jimori, Senboku city, Akita pref.; Ryukawa river - Sakamoto river - Daichi creek, Shizukuishi city, Iwate county, Iwate pref.
Fossils: Foraminifera
Fossils (Daijima-type flora):

Suto and Ishii (1987) Geology of the Shizukuishi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 142p. (in Japanese with English abstract 5p.)
Ozawa and Sumi (1958) Tazawako, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 23p. (in Japanese with English abstract 4p.)