Fuzawa Formation

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Fuzawa Formation Ministry of International Trade and Industry, 1968

Type locality: Fuzawa river, Fuzawa, Tadami city, Minamiaizu county, Fukushima prefecture
Coherent formation
middle Miocene (15 - 10 Ma; 14.4 Ma, K-Ar)
Correlation (Upper): Yuzuritoge Formation
Correlation (Lower): Ninosawa Formation

Sedimentary facies: Marine
Lithofacies (Upper): Mudstone
Lithofacies (Upper, Minor): Rhyolite tuff
Lithofacies (Lower): Rhyolite tuff, Pumiceous volcanic sandstone, Lapilli tuff, Volcanic conglomerate
Sedimentary structures (Upper): Bioturbation

Thickness: ca. 300 m
Upper limit: Conformity (Matsuzakatoge Formation), Unconformity (Minami-aizu Formation)
Lower limit: Conformity (Takizawagawa Formation)

Miyashita, Fukushima pref.
[ Upper ]
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Minami-aizu Formation
~~~~~~~~~~~~~~
Matsuzakatoge Formation
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Fuzawa Formation
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Takizawagawa Formation
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[ Lower ]

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

Distribution: Fuzawa, Tadami city, Minamiaizu county, Fukushima pref.; Showa city, Onuma county, Fukushima pref.; Komado pass - Mount Nanatsu, Minamiaizu city, Minamiaizu county,
Fossils (Shellfishes): Acila sp., Anadara sp., Dentaliidae gen. et sp. indet, Dosinia sp., Macoma sp., Mercenaria chitaniana, Mya cuneiformis
Fossils (Radiolarians): Crytocapsella tetrapera, Didymocrytis laticonus, Stichocorys delmontensis

Yamamoto and Komazawa (2004) Geology of the Miyashita District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 71p. (in Japanese with English abstract 5p.)