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Kurosedani Formation Tsuda and Chiji, 1950

Invalid synonym: Fushikidani Mudstone Member

• Type locality: Do - Kakehata, Yatsuo city, Toyama city, Toyama prefecture
• Turbidite in a rift zone
• Coherent formation
• Miocene
• Contemporaneous heterotopic facies: Kashinoki Conglomerate Member, Muromaki Conglomerate Member
• Intruded by: Andesite dikes

• Sedimentary facies: Marine, Fluvial
• Sedimentary facies: Braided river, Inner bay
• Depth of water: Tidal zone (200 - 400 m depth, Shellfish)
• Depth of water (Upper, West): Upper - middle bathyal (Foraminifera)
• Depth of water (Middle - Lower, West): Shallow marine (Foraminifera)
• Lithofacies: Interbedded conglomerate, sandstone and mudstone
• Lithofacies (Minor): Tuff breccia, Lapilli tuff, Pumice tuff
• Sedimentary structures: Cross stratificaiton

• Thickness: ca. 600 - 900 m
• Upper limit: Top of Yamadanaka Tuff
• Upper limit: Transitional (Monmyoji Alternation of Sandstone and Mudstone Member), Conformity (Higashibessho Formation, Joyama Mudstone Member)
• Lower limit: Transitional (Iozen Formation, Muromaki Conglomerate Member), Conformity (Iwaine Formation)

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

• Distribution: Do - Kakehata - Sho river - Jinzu river - Jinzu river daisan dam - Kubusugawa river - Jinpugawa river - Iwaya - Shimizu town - Nakamura, Yatsuo town, Toyama city, Toyama pref.; Kochi - Terao, Tonami city, Toyama pref.
• Fossils: Foraminifera (Miogypsina ozawai, Operculina complanata), Ostracods, Nannofossils
• Fossils (Kurosedani fauna): Acteon sp., Anadara kakehataensis, Anadara kurosedaniensis, Anadara cfr. makiyamai, Anomia sp., Babylonia sp., Batillaria yamanarii, Cardium ogurai, Cerithidea miofluviatilis, Chicoreus tiganouranus, Chlamys sp., Clementia sp., Cyclina sp., Dentalium sp., Dosinia nagaii, Dosinia nomurai, Dosinia suketoensis, Geloina sp., Gibbula sp., Joanisiella takeyamai, Meretrix sp., Nassarius sp., Natica sp., Ostrea sp., Patinopecten sp., Protorotella yuantaniensis, Sangunolaria sp., Striarca minoensis, Syrnola sp., Telescopium sp., Tellina? sp., Teredo sp., Vicarya yokoyamai, Vicaryella notoensis
• Fossils: Allospondias makiyamai, Allospondias sakamotoi, Carya sp., Comptoniphyllum naumanni, Cyclobalanopsis sp., Euscaphis sp., Fagus sp., Liquidambar formosana, Melia angularis, Picea cf. latibracteata, Pinus fujiii, Quercus cf. rubroidea, Sequoia sempervirens, Spondias axillaris var. polymeris, Tsuga rotundata
• Fossils (Pollen): Bruguiera sp., Sonneratia sp., Excoecaria sp.
• Tephra: Yamadanaka Tuff

• Nakajima et al. (2019) Jour. Geol. Soc. Japan, vol.125, no.7, pp.483-516 DOI
• Kunugiza et al. (2010) Jour. Geol. Soc. Japan, vol.116, Supplement, pp.83-101 DOI
• Yamanoi et al. (2008) Jour. Geol. Soc. Japan, vol.114, no.5, pp.262-266 DOI
• Sakamoto and Nozawa (1960) Yatsuo, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 69p. (in Japanese with English abstract 8p.)