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Naganuma Formation (Otsuka, 1937) Kanto Quaternary Research Group, 1974

Invalid synonym: Taya Formation (Upper part is Byobugaura Formation)

• Type locality: Tamanawa, Kamakura city - Naganuma, Totsuka ward, Yokohama city, Kanagawa prefecture
• Coherent formation
• Sediments by Byobugaura transgression
• Pleistocene

• Sedimentary facies: Shallow marine
• Water temperature: Warm ocean current (Shellfishes)
• Lithofacies (Upper): Sands
• Lithofacies (Upper, Minor): Pumice
• Lithofacies (Middle): Sands, Gravels
• Lithofacies (Lower): Sands
• Lithofacies (Lower, Minor): Scoria
• Sedimentary structures: Cross stratification

• Thickness: ca. 46 - 100 m or thicker
• Upper limit: Unconformity (Byobugaura Formation)
• Lower limit: Unconformity (Ofuna Formation, Nakazato Formation)

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

• Distribution: Tamanawa, Kamakura city, Kanagawa pref.; Naganuma - Iijima town - Taya town, Totsuka ward, Yokohama city, Kanagawa pref..; Hino town, Konan ward, Yokohama city, Kanagawa pref.; Shiomidai, Isogo ward, Yokohama city, Kanagawa pref.; Koayukawa river, Atsugi city, Kanagawa pref.; Shiromeguri, Kamakura city, Kanagawa pref.
• Fossils (Shellfishes): Anadara (Scapharca) broughtoni, Anomia cytaeum, Azorinus abbreviatus, Callista chinensis, Chlamys (Chlamys) ferreri, Clausinella (Placamen) tiara, Crassatella (Eucrassatella) nana, Cryptonatica janthostomoides, Dentalium (Antolis) septentrionale, Dentalium (Paradentalium) octangulatum hexagonum, Fulvia mutica, Limaria hakodatensis, Lucinoma concentricum, Myadora yokoyamai, Nassarius (Zeuxis) caelatus, Paphia (Paphia) naganumana, Pecten (Mizuhopecten) tokyoensis, Pecten (Notovola) albicans naganumanus, Ringicula doliaris, Saccella gordonis, Semelangulus miyatensis, Siphonalia spadicea, Striarca (Didimacar) tenebrica, Striarca (Galactella) interplicata, Tonna luteostoma, Umitakea japonica
• Tephra: Taya Scoria

• Oka et al. (1984) Geology of the Tokyo-Seinambu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 148p. (in Japanese with English abstract 7p.)
• Mitsunashi and Kikuchi (1982) Geology of the Yokohama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 105p. (in Japanese with English abstract 4p.)
• Oka et al. (1979) Geology of the Fujisawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 111p. (in Japanese with English abstract 5p.)