Iida Formation

Iida Formation (Suzuki, 1950) Yoshikawa et al., 2002

Invalid synonym: Iida Diatomaceous Mudstone Formation, lower Najimi Formation

Type locality (Calcareous siltstone): Higashiyamanaka town, Suzu city, Ishikawa prefecture
Type locality: Oya, Misaki town, Suzu city, Ishikawa prefecture
Coherent formation
middle Miocene (15.3 - 12.3 Ma, Diatoms, Glauconite sandstone, 15.2 Ma, K-Ar)

Sedimentary facies: Marine
Sedimentary facies: Open sea (Diatom)
Lithofacies (Top): Glauconite sandstone
Lithofacies: Calcareous siltstone, Siliceous siltstone, Diatomaceous siltstone

Thickness: 10 - 180 m
Thickness (Glauconite sandstone): 10 m or thinner
Upper limit: Conformity (Iizuka Formation)
Lower limit: Conformity (Awagura Formation)

northeast Noto peninsula
[ Upper ]
~~~~~~~~~~~~~~
Iizuka Formation
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Iida Formation
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Awagura Formation
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Hojuji Formation
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Higashiinnai Formation
~~~~~~~~~~~~~~
Horyuzan Formation
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Kamiwazumi Formation / Matsunagi Formation
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Goroku Formation
~~~~~~~~~~~~~~
Konosuyama Formation
?--?--?--?--?-
[ Lower ]

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

Distribution: Higashiyamanaka town - Wakayama town, Suzu city, Ishikawa pref.; Oya, Misaki town, Suzu city, Ishikawa pref.
Fossils: Sponges (Aphrocallistes sp.), Foraminifera, Radiolarians, Silicoflagellates
Fossils (Diatoms): Actinocyclus ingens f. ingens, Actinocyclus ingens f. nodus, Actinocyclus ingens f. planus, Actinoptychus senarius, Azpeitia vetustissima, Cavitatus miocenicus, Coscinodiscus marginatus, Crucidenticula paranicobarica, Denticulopsis lauta, Denticulopsis praehyalina, Denticulopsis tanimurae, Denticulopsis lauta, Hyalodiscus obsoletus, Nitzschia chaliengeri, Paralia sulcata, Rhizosolenia hebetata, Stephanopyxis sp., Thalassionema nitzschioides
Fossils (Trace fossils): Thalassionides isp.

Kano (2018) Jour. Geol. Soc. Japan, vol.124, no.10, pp.781-803 DOI
Yoshikawa et al. (2002) Geology of the Suzumisaki, Noto-iida and Horyuzan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 76p. (in Japanese with English abstract 4p.)