[ Top ] [ Japanese ]

Yunokogawa Formation Uemura, 1975

Same as the upper part of Kozawa Formation

• Type locality: Yunoko river, Yunokawa, Kawauchi town, Mutsu city, Aomori prefecture
• Coherent formation
• Miocene
• Correlation: Kamanosawa Tuff, Sandstone and Shale Member

• Lithofacies (Upper): Tuff
• Lithofacies (Upper, Minor): Sandstone, Conglomerate
• Lithofacies (Middle): Interbedded tuffaceous mudstone and tuff
• Lithofacies (Lower): Conglomerate, Interbedded conglomerate and sandstone, Pumice tuff = Ginnanboku Member

• Thickness: 400 m or thicker
• Thickness (Middle): 20 - 110 m
• Thickness (Basal conglomerate): 40 - 100 m or thicker
• Upper limit: Unconformity (Yunomatagawa Formation, Ohata Formation)
• Lower limit: Unconformity (Hinokigawa Formation, Yunokawa Formation)

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

• Distribution: Wajiro creek - Nayu river - Yunoko river - Shinsuke creek - Mena river, Kawauchi town, Mutsu city, Aomori pref.

• Uemura (1975) Geology of the Mutsukawauchi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 39p. (in Japanese with English abstract 7p.)
• Fossils (Shellfish): Margarites sp., Fulgoralia sp., Cancellaria sp., Arca cf. boucardi?, Anadara sp., Chlamys swiftii, Chlamys sp., Patinopecten cf. kagamianus, Lima (Acesta) sp., Monia radiata, Crassatellites sp., Venericardia sp., Protothaca? sp., Venerupis? sp., Panope japonica, Periploma? sp.