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Yashiozawakawa Formation Ozawa et al., 1988

• Type locality: Yashiozawa river, Yashima town, Yurihonjo city, Akita prefecture
• Volcanic rocks
• Miocene
• Contemporaneous heterotopic facies: Kanotsume Formation
• Correlation: Daijima Formation

• Lithofacies (Upper): Pyroxene andesite lava, Tuff breccia, Volcanic breccia
• Lithofacies (Upper, Minor): Conglomerate, Sandstone
• Lithofacies (Middle): Acidic lapilli tuff, Tuff breccia
• Lithofacies (Middle, Minor): Acidic tuff, Andesite tuff breccia, Volcanic breccia, Andesite lava
• Lithofacies (Lower): Acidic welded tuff
• Lithofacies (Lower, Minor): Acidic lapilli tuff, Tuff breccia, Tuff

• Thickness: 450 - 700 m
• Thickness (Upper): 130 - 150 m
• Thickness (Middle): 180 - 200 m
• Thickness (Lower): 150 m or thicker
• Upper limit: Conformtiy (Hatamura Formation, Aosawa Formation)

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

• Distribution: Yashiozawa river, Yashima town, Yurihonjo city, Akita pref.; Akanuma town, Yurihonjo city, Akita pref.

• Ozawa et al. (1988) Geology of the Yashima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 87p. (in Japanese with English abstract 5p.)