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Iwatsuboyama Lava Harayama, 1990

• Type locality: 1,100 m above sea level, Iwatsubodani valley, Okuhidaonsengo, Takayama city, Gifu prefecture
• Volcanic rocks
• Pleistocene (80 ka)

• Sedimentary facies: Terrestrial
• Lithofacies (Upper): Clinker
• Lithofacies (Middle): Biotite augite hornblende hypersthene dacite lava (A flow unit)
• Lithofacies (Lower): Clinker
• Sedimentary structures (Middle): Coloumnar joint

• Thickness: ca. 25 m
• Thickness (Upper): ca. 6 m
• Thickness (Lower): ca. 6 m
• Upper limit: Conformity (Upper pyroclastic flow deposit)
• Lower limit: Conformity (Lower pyroclastic flow deposit), Unconformity (Sorayama Formation)

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

• Distribution: Iwatsubodani valley - Hidarimata valley, Okuhidaonsengo, Takayama city, Gifu pref.

• Oikawa et al. (2010) Jour. Geol. Soc. Japan, vol.116, Supplement, pp.49-61 DOI
• Harayama (1990) Geology of the Kamikochi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 175p. (in Japanese with English abstract 11p.)