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Hayama Formation (Shiida and Shibata, 1968) Nishioka et al., 2001

• Type locality: Hayama, Tsuge, Nara city, Nara prefecture
• Coherent formation
• Miocene

• Sedimentary facies: Marine
• Sedimentary facies: Offshore
• Depth of water: Sublittoral
• Lithofacies (Upper): Sandstone, Siltstone
• Lithofacies (Upper, Minor): Tuff, Coal
• Lithofacies: Sandstone

• Thickness: 20 - 100 m or thicker
• Thickness (Upper): ca. 20 m
• Upper limit: Unconformity (Shiraishi Sandstone and Mudstone Member)
• Lower limit: Transitional (Sogo Formation)

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

• Distribution: Hayama - Mount Tsugenodake, Tsuge, Nara city, Nara pref.; Mukoji - Kaiba - Tenmadai, Uda city, Nara pref.; Mount Kaigahirayama, Sakurai city, Nara pref.
• Fossils: Echinoids (Linthia nipponica), Foraminifera
• Fossils (Shellfishes): Acila cf. divaricata, Ancistrolepis miensis, Calyptraea sp., Cardiomya sp., Cavolina sp., Cerithidea? sp., Cirsostrema sp., Clinocardium sp., Dentalium sp., Ennucula sp., Eoscaphander corpulenta, Epitonium sp., Fulgoraria miensis, Liocyma cf. minuta, Lucinoma acutilineatum, Macoma izurensis, Macoma optiva, Minolia sp., Nassarius sp., Nuculana pennula, Panomya simotomensis, Periploma mitsuganoense, Portlandia sp., Puncturella sp., Riuguhdrillia sp., Saccella miensis, Serripes cf. laperousii, Tectonatica sp., Teredo sp., Thyasira sp., Tristichotrochus sp., Turritella sagai, Venericardia (Cyclocardia) sigamensis, Yoldia (Cnesterium) sp., Yoldia (Orthoyoldia) sagittaria
• Fossils (Trace fossils): Cylindrichnus isp., Ophiomorpha isp., Skolithos isp.

• Sato et al. (2012) Jour. Geol. Soc. Japan, vol.118, Supplement, pp.53-69 DOI
• Nishioka et al. (2001) Geology of the Sakurai District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 141p. (in Japanese with English abstract 5p.)