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Hideshima Formation

• Type locality: Hideshima island, Miyako city, Iwate prefecture
• Coherent formation
• Early Cretaceous, Albian or later
• Intruded by: Jodogahama Rhyolite

• Sedimentary facies: Marine
• Sedimentary facies: Sediment gravity flow (Turbidite, Debris flow, Slump)
• Depth of water: Continental slope - Basin floor
• Lithofacies: Interbedded sandstone and mudstone, Sandstone
• Lithofacies (Minor): Conglomerate, Gravel-bearing mudstone, Tuff
• Sedimentary structures: Paralle stratification, Cross stratification, Climbing-ripples, Comvolute lamination, Graded bedding

• Thickness: 70 m or thicker
• Upper limit: Unknown
• Lower limit: Unknown

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

• Distribution: Hideshima island, Miyako city, Iwate pref.
• Fossils (Bivalves): Glycymeris, Eriphyla, Nipponitrigonia, Rudists
• Fossils (Foraminiferas): Bathysiphon spp., Recurvoides spp., Haplophragmoides spp., Glomospira sp., Haplophragmoides sp., Trochammina sp., Reophax sp., Gaudryina sp., Ammodiscus sp., Spiroplectammina sp., Ramulina sp.

• Urakawa et al. (2017) Jour. Geol. Soc. Japan, vol.123, no.3, pp.121-130 DOI
• Yoshida and Katada (1984) Geology of the Miyako District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 44p. (in Japanese with English abstract 6p.)
• Shimazu et al. (1970) Geology of the Taro District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 54p. (in Japanese with English abstract 6p.)