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Yamada Sandstone and Conglomerate Member (Kosaka and Yamagishi, 1988) Yamada et al., 2004

Invalid synonym: Yamada Sandstone and Conglomerate Facies

• Type locality: Yamada, Asama hotspring, Matsumoto city, Nagano prefecture
• Coherent formation
• middle Miocene (15.8 Ma, FT)
• Contemporaneous heterotopic facies: Takenoyu Volcanics Member
• Intruded by: Felsic intrusive rocks

• Sedimentary facies: Continental shelf
• Lithofacies: Sandstone, Conglomerate, Mudstone-dominant interbedded sandstone and mudstone
• Lithofacies (Upper, Minor): Felsic tuff
• Sedimentary structures: Trough cross stratification, Parallel stratification, Graded bedding
• Paleocurrent: from Southwest to Northeast

• Thickness: ca. 250 - 450 m
• Thickness (Tuff): 20 m
• Upper limit: Conformity (Asamatoge Sandstone and Mudstone Member)
• Lower limit: Conformity (Fujii Sandstone and Mudstone Member, Mozawa Tuffaceous Sandstone Member)

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

• Distribution: Yamada - Asama hotspring - Kitabora - Inagura - Nakayama - Shimoizumi - Mount Chikatoyama - Funegasawa creek - Nakazawa creek - Lake Misuzuko - Fujiisawa creek - Oikurasawa creek, Matsumoto city, Nagano pref.
• Fossils: Shellfishes (Chlamys sp., Ostrea sp.), Trace fossils

• Kosaka et al. (2022) Earth Science (Chikyu Kagaku), vol.76, no.4, pp.179-194 DOI
• Harayama et al. (2009) Geology of the Matsumoto District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 63p. (in Japanese with English abstract 3p.)