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Fudonotaki Formation Iizuka, 1930

Invalid synonym: Fudonotaki Formation, Shiokoshi Formation, Shiwokoshi Formation, Imaizumi Formation, Kanagi Formation, upper Iizume Formation, Kareizawa Formation

• Type locality: Fudo fall, Iizume, Goshogawara city, Aomori prefecture
• Coherent formation
• late Miocene (10.0 - 7.5 Ma, Kitaura stage)
• Contemporaneous heterotopic facies: Imabetsu Andesites, Masukawagawa Andesites?, Karasudake Rhyolite, Masukawadake Dacite
• Contemporaneous heterotopic facies (Lower): Genpachimori Formation
• Correlation: Isodayama Formation

• Sedimentary facies: Pyroclastic flow deposit
• Lithofacies: Diatomaceous mudstone, Sandstone, Conglomerate
• Lithofacies (Minor): Basaltic lapilli tuff, Basaltic tuff breccia, Tuffaceous sandstone, Rhyolite lava, Shale, Felsic tuff, Sandy tuff, Dacite
• Sedimentary structures: Graded bedding, Cross stratification, Parallel stratification

• Thickness: 50 - 650 m or thicker
• Upper limit: Conformity (Kanita Formation, Misogasawa Formation, Imabetsu Andesites), Unconformity (Isodayama Formation)
• Lower limit: Reaction boundary by diagenesis from diatoms to quartz
• Lower limit: Interbedded tuffaceous sandstone and glauconite-bearing shale?
• Lower limit: Transitional (Genpachimori Formation), Unconformity (Fuyube Formation, Ota Tuff Member)

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

• Distribution: Kodomari - Imaizumi - Nakasato, Nakadomari city, Kitatsugaru county, Aomori pref.; Mimmaya, Sotogahama city, Higashitsugaru county, Aomori pref.; Horozuki seashore, Horozuki - Yomonai river - Sekiguchi creek, Imabetsu city, Higashitsugaru county, Aomori pref.; Rokumaibashi river, Aomori pref.; Fudo fall, Iizume, Goshogawara city, Aomori pref.
• Fossils: Sponges (Sagarites = Makiyama chitanii, Spicules), Radiolarians (Liosphaericae, Ellipsidiicae, Cenodiscicae, Sethopiliilae, Theopiliilae), Pipe rocks
• Fossils (Diatoms): Actinocyclus ehrenbergii var. ralfsii, Actinoptychus cfr. undulatus, Arachnoidiscus sp., Chaetoceros spp., Cocconeis antiqua, Cocconeis curvirotunda, Cocconeis formosa, Cocconeis vitrea, Coscinodiscus elegans, Coscinodiscus marginatus, Coscinodiscus stellaris var. symbolophora, Coscinosira sp., Denticula hustedtii, Denticula lauta, Eunotia sp., Eutogramma sp., Fragilariopsis pliocenum, Grammatophora sp., Melosira italica, Melosira sulcata, Nitzschia pliocena, Opephora sp., Pyxila cfr. capreolus, Rouxia californica, Rouxia peragalli, Rhizosolenia sp., Thalassionema nitzschioides (= Thalassionema hirosakiensis), Thalassiothrix longissima, Thalassiosira antiqua, Thalassiosira haynaldiella, Thalassiosira maruyamica, Thalassiosira cfr. oculatus, Thalassiosira spp., Triceratium spp.

• Nagamori et al. (2013) Geology of the Aomori-Seibu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 67p. (in Japanese with English abstract 4p.)
• Kamikuri et al. (2010) Jour. Geol. Soc. Japan, vol.116, no.8, pp.403-411 DOI
• Fujii (1981) Geology of the Aburakawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 38p. (in Japanese with English abstract 3p.)
• Fujii (1966) Kanagi, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 40p. (in Japanese with English abstract 4p.)
• Uemura et al. (1959) Kanita, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 30p. (in Japanese with English abstract 5p.)
• Tsushima and Uemura (1959) Kodomari, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 45p. (in Japanese with English abstract 5p.)
• Ota et al. (1957) Mimmaya, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 30p. (in Japanese with English abstract 5p.)