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Horyuzan Formation Yoshikawa et al., 2002

Invalid synonym: Tokunari Formation

• Type locality (Pyroclastic rocks): Terayama - Mount Horyuzan, Machino town, Wajima city, Ishikawa prefecture
• Type locality (Lava): Akazaki, Nunoura, Noto city, Hosu county, Ishikawa prefecture
• Volcanic rocks
• early Miocene (20 - 18 Ma; 19.5 Ma, FT)
• Dykes: early Miocene (18.3 Ma, FT)
• Intruded by: Pyroxene dacite - Rhyolite dikes

• Sedimentary facies: Volcanic ash cloud surge, Pyroclastic fall deposit
• Sedimentary facies: Pyroclastic flow deposit
• Sedimentary facies (Lower): Ground surge
• Lithofacies: Dacite tuff, Pumiceous lapilli tuff, Tuff breccia
• Lithofacies (Minor): Pyroxene dacite - Rhyolite lava, Siltstone, Sandstone, Conglomerate
• Sedimentary structures: Parallel stratificaiton, Cross stratification

• Thickness: A few dozen - 300 m or thicker
• Thickness (A flow unit): 10 - 40 m or thicker
• Upper limit: Unconformity (Higashiinnai Formation, Hojuji Formation)
• Lower limit: Conformity (Kamiwazumi Formation, Matsunagi Formation), Unconformity (Goroku Formation, Konosuyama Formation)

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

• Distribution: Terayama - Mount Horyuzan, Machino town, Wajima city, Ishikawa pref.; Akazaki - Matsunami, Nunoura, Noto city, Hosu county, Ishikawa pref.; Mount Yamabushiyama - Ishigami town - Mount Kendaradake, Suzu city, Ishikawa pref.
• Fossils: Charcoal, Silicified woods
• Fossils: Noroshi flora

• Kano (2018) Jour. Geol. Soc. Japan, vol.124, no.10, pp.781-803 DOI
• Yoshikawa et al. (2002) Geology of the Suzumisaki, Noto-iida and Horyuzan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 76p. (in Japanese with English abstract 4p.)