[ Top ] [ Japanese ]

Yonamine Formation

Yonamine Formation in a broad sense by Nakae et al. (2010) is overall Motobu Unit excluding Wakugawa Formation.

• Type locality: Yonamine, Okinawa prefecture
• Accretionary complex
• Deposition (Limestone): Permian
• Deposition (Chert): Middle- Late Triassic (Conodonts, Radiolarians)
• Metamorphism: Late Cretaceous (75.2 - 70.2 Ma, K-Ar)

• Lithofacies: Mélange facies
• Matrix: Gravel-bearing mudstone, Sandstone, Conglomerate, Tuff, Siliceous rock
• Exotic blocks (Crusts): Limestone, Calcareous conglomerate, Chert, Greenstone

• Upper limit: Thrust fault?
• Lower limit: Thrust fault?

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

• Distribution: Yonamine, Okinawa pref.
• Fossils (Chert): Conodonts, Radiolarians

• Miyagi et al. (2013) Jour. Geol. Soc. Japan, vol.119, no.10, pp.665-678 DOI