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Genpachimori Formation Iizuka, 1930

Invalid synonym: Gempachimori Formation, upper Kodomari Formation, lower Iizume Formation, Wakayama Formation, Toyamori Formation

• Type locality: Genhachimori, Kiraichi, Kanagi town, Goshogawara city, Aomori prefecture
• Coherent formation
• middle - late Miocene (15.0 - 8.0 Ma, Radiolarians, Diatoms, Funakawa stage)
• Contemporaneous heterotopic facies: Tappi Volcanic Rocks, Horozuki Volcanic Rocks, Mimmaya Rhyolites
• Contemporaneous heterotopic facies (Upper): Imabetsu Andesites, Fudotaki Formation
• Intruded by: Basalt, Masukawadake Dacite

• Sedimentary facies: Marine
• Lithofacies: Mudstone
• Lithofacies (Minor): Diatomaceous mudstone, Sandy mudstone, Andesitic - Rhyolitic tuff

• Thickness: 0 - 1,000 m
• Upper limit: Interbedded tuffaceous sandstone and glauconite-bearing shale
• Upper limit: Conformity (Fudotaki Formation, Horozuki Volcanic Rocks), Unconformity (Upper Nihonmatsu Tuff, Isodayama Formation, Obirakiyama Pyroclastic Flow Deposit)
• Lower limit: Conformity (Ota Pumiceous Volcaniclastic Rocks, Nyunai Formation)

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

• Distribution: Kodomari, Nakadomari city, Kitatsugaru county, Aomori pref.; Masukawa river, Sotogahama city, Higashitsugaru county, Aomori pref.; Yomonai river - Sekiguchi creek, Imabetsu city, Higashitsugaru county, Aomori pref.; Genhachimori, Kiraichi, Kanagi town, Goshogawara city, Aomori pref.; Takizawa, Magonai river, Osawa river, Aomori city, Aomori pref.
• Fossils: Sponges (Sagarites = Makiyama chitanii), Foraminifera (Bathysiphon sp., Haplophragmoides sp., Cyclammina sp., Martinottiella communis, Spirosigmoilinella compressa), Radiolarians (Liosphaericae, Ellipsidiicae, Cenodiscicae, Theopiliilae, Stichocorys delmontensis, Stichocorys peregrina), Diatoms (Coscinodiscus sp., Arachnoidiscus sp., Thalassionema schraderi), Trace fossils

• Hoshi et al. (2016) Jour. Geol. Soc. Japan, vol.122, no.4, pp.163-170, DOI
• 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.)
• Saito and Uemura (1957) Horozuki, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 26p. (in Japanese with English abstract 7p.)
• 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.)