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Hachiya Formation Yabe, 1921 ex Saga, 1917

• Type locality: Hachiya town, Minokamo city, Gifu prefecture
• Coherent formation
• First Seto Inland Sea
• Sedimentary basin in island arc
• early Miocene (22.2, 20.6, 19.8 Ma, K-Ar; 22.7 Ma, FT)

• Sedimentary facies: Lacustrine
• Lithofacies: Rhyolite - Andesite - Basalt lava, Volcanic breccia, Tuff breccia, Hyaloclastite
• Lithofacies (Minor): Tuffaceous sandstone, Conglomerate, Tuffaceous siltstone

• Thickness: 10 - 60 m or thicker
• Lower limit: Unconformity (Kamiaso Unit)

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

• Distribution: Hachiya town - Ichihashi, Minokamo city, Gifu pref.; Kaneyama - Nishikatabira, Kani city, Gifu pref.; Yuta - Kajita, Tomika town, Kamo county, Gifu pref.; Oharai, Sakahogi city, Kamo county, Gifu pref.
• Fossils (Aniai-type flora): Magnolia miocenica, Metasequoia occidentalis, Pterocarya asymmetrosa

• Shinjoe et al. (2018) Jour. Geol. Soc. Japan, vol.124, no.7, pp.533-538 DOI
• Ina et al. (2007) Jour. Geol. Soc. Japan, vol.113, no.10, pp.542-545 DOI
• Yoshida and Wakita (1999) Geology of the Gifu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 71p. (in Japanese with English abstract 4p.)
• Wakita (1995) Geology of the Mino District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 36p. (in Japanese with English abstract 3p.)
• Mizutani and Koido (1992) Geology of the Kanayama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 111p. (in Japanese with English abstract 9p.)