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Iizawa Formation Ozawa et al., 1979

Invalid synonym: Yokonetoge Formation

• Type locality: Iwadai, Iizawa, Ugo city, Ogachi county, Akita prefecture
• Volcanic rocks
• Miocene
• Contemporaneous heterotopic facies: Okachigawa Formation, Sarakawa Formation
• Contemporaneous heterotopic facies (Upper): Shigenosawa Andesite Member

• Lithofacies: Pyroxene andesite lava (Hyaloclastite), Tuff breccia, Volcanic breccia, Lapilli tuff
• Lithofacies (Minor): Pyroxene andesite tuff, Acidic tuff, Lapilli tuff, Mudstone

• Thickness: 100 - 500 m
• Upper limit: Conformity, partly unconformily (Hatamura Formation, Daisenyama Formation), Unconformity (Sugota Formation)
• Lower limit: Conformity (Yunosawagawa Formation), Unconformity (Kamuroyama Granites)

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

• Distribution: Iwadai - Akasawaguchi, Iizawa, Ugo city, Ogachi county, Akita pref.; Iwaizawa river - Oikata - Mount Mitsumori - Matsuzawa - Sakanoshita, Higashiyuri, Yurihonjo city, Akita pref.; Mount Haihei - Nanamagari pass, Ugo city, Ogachi county, Akita pref.; Matsuoka, Yuzawa city, Akita pref.
• Fossils (Aniai-type flora): Alnus? sp., Betula sp., Carpinus sp., Celtis sp., Crataegus okamotoi, Crataegus sugiyamai, Glyptostrobus europaeus, Metasequoia occidentalis, Osmunda japonica, Osmunda tsunemoroensis, Picea ugoana, Pinus sp., Thuja sp., Zelkova? sp.

• Ozawa et al. (1979) Geology of the Asamai District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 53p. (in Japanese with English abstract 4p.)
• 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.)