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Ogane Formation

• Coherent formation
• Miocene (12.0 - 11.0 Ma, Ar-Ar, K-Ar)

• Sedimentary facies: Marine
• Lithofacies (Upper): Mudstone, Pumiceous sandy tuff, Tuff, Diatomaceous sandy mudstone
• Lithofacies (Middle): Interbedded pumice Tuff, sandy tuff, and sandy mudstone (3 sets)
• Lithofacies (Lower, Main): Muddy sandstone, Sandy mudstone, Mudstone
• Lithofacies (Lower, Minor): Tuff, Pumice tuff

• Upper limit: Conformity (Tanokura Formation)
• Lower limit: Conformity (Kobana Formation)

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

• Distribution: Shiota, Ichikai city, Haga county, Tochigi pref.; Magatta - Takase - Junikuchi - Kumada, Nasukarasuyama city, Tochigi pref.; Yoshida, Nakagawa city, Nasu county, Tochigi pref.
• Fossils (Upper, Shiobara-Yama fauna)
• Fossils (Middle, Shiobara-Yama fauna): Aradara ninohensis, Phos iwakianus, Serripes groenlandicus, Neptunea koromogawana, Buccinum sp., Cultellus izumoensis, Lucinoma acutilineata, Macoma optiva, Mya cuneiformis, Panomya simotomensis, Dosinia cf. kaneharai, Mercenaria cf. yokoyamai, Glycymeris, Lucinoma acutilineata, Clinocardium sp., Anadara ninohensis, Macoma optiva, Mya cuneiformis, Acila divaricata, Cultellus izumoensis, Phos iwakianus, Dosinia cf. kaneharai, Mercenaria cf. yokoyamai, Glycymeris sp.
• Fossils (Lower, Shiobara-Yama fauna): Cyclocardia siogamensis, Thracia sp., Neptunea hukusimensis

• Matsui et al. (2011) Jour. Geol. Soc. Japan, vol.117, Supplement, pp.89-102 DOI
• Hayashi et al. (2008) Jour. Geol. Soc. Japan, vol.114, no.3, pp.141-144 DOI