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Shiriya Group Imai, 1961

Invalid synonym: Shiriya Formation, Shimokita Group

• Accretionary complex
• Deposition (Limestone): Late Jurassic - Early Cretaceous
• Accretion: Late Jurassic, Tithonian - Early Cretaceous
• Intruded by: Quartz diorite porphyry

• Sedimentary facies: Marine
• Lithofacies: Slate (Shale), Chert, Limestone, Sandstone, Conglomerate, Mafic volcanic rocks

• Thickness: 3,500 m or thicker
• Upper limit: Unconformity (Sarugamori Formation, Tomari Formation, Sunagomata Formation, Tanabu Formation)

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

• Distribution: Cape Shiriya, Shiriya, Higashidori city, Shimokita county, Aomori pref.
• Fossils (Limestone, Hexacorals): Kobya shiriyaensis, Calamophyllia? sp., Thecosmilia? sp., Thamnasteria cf. haradai, Milleporidium sp., Rhabdophyllia sp., Chaetetopsis? sp.
• Fossils (Limestone, Stromatopods): Stromatopora (Parastromatopora) crassifibra, Stromatopora (Parastromatopora) memoria-naumanni
• Fossils (Limestone fissure): Bos or Bison sp., Canis lupus, Capricornis crispus, Megaceros sp., Microtus montebelli, Nyctereutes procyonides, Palaeoloxodon aomoriensis, Ursus arctos or U. spelaeus, Vulpes sp., Frogs
• Fossils (Limestone fissure, Land snails): 15 species, Carychium pessimum, Discus ruderatus, Hawaiia minuscula

• Ehiro et al. (2008) Jour. Geol. Soc. Japan, vol.114, Supplement, pp.121-139 DOI
• Tsushima and Takizawa (1977) Geology of the Shiriyazaki District, Quadrangle Series, 1:50,000, Geological Survey of Japan, 32p. (in Japanese with English abstract 4p.)
• Imai (1961) Chikagawa, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 45p. (in Japanese with English abstract 4p.)