Akaragi Unit

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Akaragi Unit Kawato et al., 1991

There is an opinion that this unit and Mikabu Unit are separated as Mikabu Belt.

Invalid synonym: Sasagatani Formation

Type locality: Akaragi pass, Tosa city, Tosa county, Kochi prefecture
Accretionary complex
Deposition: Jurassic (131.2 Ma, FT)
Metamorphism: Cretaceous (105 Ma, K-Ar)
Correlation: Kashiwagi Unit, Omoiji Unit

Sedimentary facies: Marine
Metamorphic facies: ca. 290 degree C, 0.65 GPa
Lithofacies: Chert
Lithofacies (Minor): Basalt, Dolerite, Mafic phyllite, Phyllite, Dolomitic limestone, Sandstone

Upper limit: Thrust fault (Kamiananai Unit)
Lower limit: Thrust fault (Mikabu Unit)

Northern Chichibu Belt (Motoyama, Kochi pref.)
[ Upper ]
/--/--/--/--/-
Akatsukayama Unit
/--/--/--/--/-
Nishimata Unit
/--/--/--/--/-
Kamiananai Unit
/--/--/--/--/-
Akaragi Unit
/--/--/--/--/-
[ Lower ]

Chichibu Belt
[ Upper ]
/--/--/--/--/-
Kurosegawa Belt
/--/--/--/--/-
Northern Chichibu Belt
/--/--/--/--/-
Southern Chichibu Belt
/--/--/--/--/-
[ Lower ]

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

Distribution: Akaragi pass - Sasagatani, Tosa city, Tosa county, Kochi pref.; Higashiionotani, Otoyo city, Nagaoka county, Kochi pref.; Ubagatani, Kami city, Kochi pref.
Fossils (Conodonts): Epigondolella primitia, Gondolella clarki, Gondolella gymna, Idiognathodus cf. delicates, Idiognathoides sinuatus, Neognathodus symmetricus, Neogondolella sp.

Endo and Yokoyama (2019) Geology of the Motoyama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 100p. (in Japanese with English abstract 4p.)