[ Top ] [ Japanese ]

Yamami Formation Shibata, 1977

Invalid synonym: Hajikami Formation, Kumura Formation, Yamami Siltstone Member

• Type locality: Mountain pass between Yamami and Nakiri, Minamichita city, Chita county, Aichi prefecture
• Coherent formation
• Miocene

• Sedimentary facies: Marine
• Lithofacies (Upper): Mudstone-dominant interbedded sandstone and mudstone
• Lithofacies (Lower): Siltstone, Tuffaceous sandstone, Tuff
• Lithofacies (Lower, Minor): Breccia
• Sedimentary structures (Upper, Minor): Slump structures

• Thickness: ca. 270 m
• Upper limit: Bottom of Nakiri Tuffaceous Sandstone
• Upper limit: Conformity (Utsumi Formation)
• Lower limit: Bottom of Hasu Tuffaceous Sandstone
• Lower limit: Conformity (Toyohama Formation)

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

• Distribution: Yamami - Nakiri - Toyooka - Utsumi - Cape Nomazaki - Tsubutegaura, Minamichita city, Chita county, Aichi pref.
• Fossils: Fishes (Cyclothone sp.), Echinoids (Linthia nipponica)
• Fossils (Shellfishes): Acesta goliath, Acila (Truncacila) sp., Acilana tokunagai, Ancistrolepis sp., Bathymalletia chilensis, Bowdenatheca sp., Buccinum sp., Calyptogena sp., Carinineilo takeharai, Chlanidota mitsuganoensis, Ctenamussium sp., Cyclocardia siogamensis, Euclio balantium, Eunucula cfr. osawanoensis, Euspira mitsuganoensis, Fissidentalium cfr. yokoyamai, Laevidentalium sp., Limatula sp., Lucinoma acutilineatum, Machaeroplax mitsuganoensis, Macoma? sp., Malletia inermis, Megasureula cfr. osawanoensis, Neilonella isensis, Neilonella oveta, Nipponoscaphander sp., Nuculana pennula, Omniglypta sp., Palliolum (Delectopecten) peckhami, Pandora (Pandorella) cfr. otukai, Periploma mitsuganoensis, Phanerolepida cfr. expansilabrum, Phaxas izumoensis, Poromya sp., Portlandia kakimii, Propeamussium tateiwai, Propebela takamiyaensis, Ringuhdrillia oyamae, Saccella miensis, Spirotropis mitsuganoensis, Tachyrhnchus mitsuganoensis, Tectonatica ichishiana, Thyasira sp., Trophonopsis sp., Turritella ichishiensis, Yoldia sagitaria,
• Tephra: Fukkoshi Tuff, Daihoji Tuff

• Muramiya et al. (2017) Jour. Geol. Soc. Japan, vol.123, no.11, pp.939-952 DOI
• Kondo and Kimura (1987) Geology of the Morozaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 93p. (in Japanese with English abstract 5p.)