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Yagisawa Mudstone Member (Otsuka, 1955) Ozaki and Sugiyama, 2018

Invalid synonym: Yagisawa mudstone, Hadakajima Formation

• Type locality: Fujikawa river, Shimoyagisawa, Minobu city, Minamikoma county, Yamanashi prefecture
• Coherent formation
• late Miocene - Pliocene
• Contemporaneous heterotopic facies: Marutaki Conglomerate Member
• Correlation (Lower): Omorozawa Member
• Intruded by: Shimobe Intrusive Rocks

• Sedimentary facies: Marine
• Lithofacies: Siltstone, Mudstone-dominant interbedded mudstone and sandstone
• Lithofacies (Lower): Andesite tuff, Lapilli tuff, Sandstone, Mudstone
• Lithofacies (Lower, Minor): Andesite volcanic breccia, Tuff breccia, Volcanic conglomerate, Tuff, Lava, Hornblende dacite tuff, Tuff breccia
• Sedimentary structures: Parallel stratification

• Thickness: ca. 2,200 m
• Upper limit: Conformity (Hakii Interbeds of Sandstone and Mudstone Member)
• Lower limit: Conformity (Shimobe Formation)

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

• Distribution: Shimoyagisawa - Kamiyagisawa - Shimoyama - Onuta - Tsubakizori, Minobu city, Minamikoma county, Yamanashi pref.

• Ozaki and Sugiyama (2018) Geology of the Minobu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 169p. (in Japanese with English abstract 7p.)