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Wanakurasawa Unit Hara and Hisada, 1998

Invalid synonum: Tochimoto Formation, Nakayama Formation

• Type locality: confluence of the Wanakurazawa creek and the Oboragawa river, Otaki, Chichibu city, Saitama prefecture
• Accretionary complex
• Deposition (Shale): Early Cretaceous, late Albian - Late Cretaceous, Cenomanian
• Accretion: Early Cretaceous, late Albian - Late Cretaceous, Cenomanian

• Sedimentary facies: Marine
• Lithofacies: Sandstone, Shale, Sandstone-dominant interbedded sandstone and shale
• Lithofacies (Minor): Broken facies
• Sedimentary structures: Graded bedding

• Thickness: ca. 2,000 m
• Lower limit: Thrust fault (Ichinosawa Unit)

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

• Distribution: Wanakurazawa creek - Oboragawa river, Otaki, Chichibu city, Saitama pref.; Nagasawadani - Ogochi dam - Tochiyorizawa - Nippara river - Ogochi pass - Yukubo -Natsuchi, Okutama city, Nishitama county, Tokyo
• Fossils (Radiolarians): Archacodictyomitra sp., Hemicryptocapsa polihedra, Holocryptocanium barbui, Holocryptocanium barbui japonicum, Parvicingula boesii, Pseudodictyomitra sp., Thanarla praevenela

• Hara et al. (2010) Geology of the Mitsumine District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 110p. (in Japanese with English abstract 4p.)
• Sakai (1987) Geology of the Itsukaichi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 75p. (in Japanese with English abstract 5p.)