Akaiwa Formation

Type locality: Kazarashi - Akaiwa - Ichinose, Tetori river, Hakusan city, Ishikawa prefecture
Coherent formation
Early Cretaceous, Aptian, (121.2 Ma, U-Pb)

Sedimentary facies: Terrestrial
Lithofacies (Main): Sandstone, Conglomerate, Interbedded sandstone and mudstone
Lithofacies (Minor): Mudstone
Sedimentary structures: Trough cross-stratification

Thickness: 720 - 1,400 m
Upper limit: Unconformity (Omichidani Formatino)
Lower limit: Transitional (Kuwajima Formation)

Akaiwa Subgroup (Ishikawa pref. - Fukui pref.)
[ Upper ]
~~~~~~~~~~~~~~
Kitadani Formation
--------------
Akaiwa Formation
--------------
[ Lower ]

Tetori Group
[ Upper ]
~~~~~~~~~~~~~~
Akaiwa Subgroup
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Itoshiro Subgroup
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Shiromine, Ishikawa pref. - Takinami river, Katsuyama city, Fukui pref.
Distribution: Kazarashi - Akaiwa - Ichinose - Akadani river - Shimotawara river - Myodani river - Byakodani river - Mount Oarashi - Nishijima pass - Osugi river, Hakusan city, Ishikawa pref.; Tochigamiya - Sugiyama river - Ohara, Katsuyama city, Fukui pref.
Fossils: Vertebrata, Turtles, Shellfishes
Fossils (Akaiwa flora): Thallites sp., Adiantopteris ginkgoifolia, Cladophlebis spp., Eboracia nipponica, Gleichenites nipponensis, Onychiopsis elongata, Osmundopsis distans, Raphaelia diamensis, Ginkgoidium nathorsti, Ginkgoites digitata, Ginkgoites huttonii, Brachyphyllum? sp., Elatocladus spp., Pityophyllum sp., Podozamites lanceolatus, Podozamites reinii, Taeniopteris emarginata, Taeniopteris vittata

Sakai et al. (2019) Jour. Geol. Soc. Japan, vol.125, no.3, pp.255-260 DOI
Sakai et al. (2018) Jour. Geol. Soc. Japan, vol.124, no.3, pp.171-189 DOI