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Muraoka Formation

• Type locality: Muraoka, Kami city, Mikata county, Hyogo prefecture
• Coherent formation
• Miocene (16 - 14 Ma, Fossils, Strata correlation; 17.0 - 10.9 Ma, FT; 16.9, 16.7 Ma, U-Pb)
• Contemporaneous heterotopic facies: Amino Formation
• Correlation: Upper Iwami Formation, Tottori Group

• Sedimentary facies: Marine
• Sedimentary facies: Inner - middle shelf
• Lithofacies (Top): Andesitic tuff breccia
• Lithofacies (Upper): Interbedded shale and siltstone
• Lithofacies (Middle): Sandstone
• Lithofacies (Lower): Tuff
• Lithofacies (Bottom): Conglomerate
• Lithofacies (Minor): Rhyolitic pyroclastic rocks
• Sedimentary structures: Parallel stratification, Hummocky cross-stratification

• Thickness: 1,000 m or thicker
• Upper limit: Unconformity (Oginosen Volcanic Rocks)
• Lower limit: Conformity (Toyooka Formation)

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

• Distribution: northeast Tottori pref.
• Distribution: Mount Myoken - Saruodaki Fall - Mount Sobu, Muraoka-ku, Kami city, Mikata county, Hyogo pref.
• Fossils (Sandstone): Shellfishes, Foraminifera (Operculina complanata japonica, Miogypsina sp.)

• Haji and Yamaji (2019) Jour. Geol. Soc. Japan, vol.125, no.9, pp.685-698 DOI
• Haji and Yamaji (2017) Jour. Geol. Soc. Japan, vol.123, no.12, pp.1049-1054 DOI
• Sakiyama et al. (2012) Jour. Geol. Soc. Japan, vol.118, Supplement, pp.1-20 DOI
• Utada (2008) Jour. Geol. Soc. Japan, vol.114, no.5, pp.231-245 DOI