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Akiyamago Formation Shimazu and Tateishi, 1993

• Volcanic rocks
• middle - late Miocene
• Correlation: Mugurazawa Formation?

• Lithofacies: Andesite - dacite volcaniclastic rocks, Clastic rocks

• Upper limit: Unconformity (Takai Volcanic Rocks, Takayamazawa-Onizawa Pyroclastic Flow Deposit, Uenohara Welded Tuff, Shirakurayama Lavas, Erakubodaira Volcanic Rocks)
• Lower limit: Unconformity (Zakogawae Formation, Ketto Formation)

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

• Distribution: Nakatsu river, Sakae city, Shimominochi county, Nagano pref.

• Igarashi et al. (2007) Jour. Geol. Soc. Japan, vol.113, no.11, pp.565-584 DOI
• Shimazu and Tateishi (1993) Geology of the Naebasan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 90p. (in Japanese with English abstract 5p.)