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Daisenyama Formation Ozawa et al., 1979

• Type locality: Minamizawa river - Daisen river, Innai, Yuzawa city, Akita prefecture
• Volcanic rocks
• Miocene
• Contemporaneous heterotopic facies: Hatamura Formation
• Correlation: upper Daijima Formation

• Lithofacies: Olivine basalt lava, Olivine augite basalt lava (Pillow lava, Hyaloclastite), Lapilli tuff, Tuff
• Lithofacies (Minor): Basalt tuff breccia, Volcanic breccia, Pyroxene andesite tuff, Lapilli tuff, Tuff breccia, Acidic tuff, Sandstone, Mudstone

• Thickness: 100 - 450 m
• Upper limit: Conformity (Sugota Formation)
• Lower limit: Conformity, partly unconformity (Sarakawa Formation, Iizawa Formation), Unconformity (Okachigawa Formation)

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

• Distribution: Minamizawa river - Daisen river - Hokizawa river - Mount Daisen, Innai, Yuzawa city, Akita pref.; Sarakawa - Mount Ubaido, Chokai town, Yurihonjo city, Akita pref.
• Fossils: Silicified woods
• Fossils (Daijima-type flora): Alnus miojaponica, Carpinus sp., Fraxinus sp., Mochilus ugoana, Ostrya shiragiana, Salix sp.

• Ozawa et al. (1979) Geology of the Yuzawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 64p. (in Japanese with English abstract 4p.)