Yambarazaka Alternation Member

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Yambarazaka Alternation Member

Coherent formation
Middle - Late Jurassic

Sedimentary facies: Marine
Lithofacies: Interbedded sandstone and shale

Thickness: 43 - 150 m
Lower limit: Conformity (Kaizara Shale Member)

Shimoanama Formation
[ Upper ]
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Yambarazaka Alternation Member
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Kaizara Shale Member
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Kamiwakago Conglomerate Member
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[ Lower ]

Kuzuryu Group (Ono, Fukui pref.)
[ Upper ]
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Shimoanama Formation
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Arashimadani Formation
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[ Lower ]

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

Distribution: Asahi - Shimoyama - Kaizara - Hakogase - Nagano - Mount Washikuragatake - Hinotani valley - Isegawa river, Ono city, Fukui pref.
Fossils: Belemnoids
Fossils (Ammonoids): Calliphylloceras sp., Karanosphinctes cf. matsushimai, Perisphinctids
Fossils (Plants): Cladophlebis distans

Kawai et al. (1957) Arashimadake, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 110p. (in Japanese with English abstract 13p.)