Hirose Formation

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Hirose Formation Ishida and Kozai, 2004

Type locality: Hirose, Naga city, Naga county, Tokushima prefecture
Accretionary complex
Early Jurassic, Hettangian - Pliensbachian
Correlation: Ottate Group
Correlation (Limestone): Torinosu Group

Sedimentary facies: Shallow marine
Lithofacies: Turbidite
Lithofacies: Interbedded sandstone and mudstone
Lithofacies (Bottom): Conglomerate
Sedimentary structures: Upward-fining

Thickness: 50 - 300 m
Thickness (Conglomerate): 2 m
Lower limit: Unconformity (Sabudani Formation)

Sakashu Group
[ Upper ]
/--/--/--/--/-
Kurisaka Formation
?--?--?--?--?-
Hirose Formation
~~~~~~~~~~~~~~
[ Lower ]

Kurosegawa Belt (Sakashu, Tokushima pref.)
[ Upper ]
/--/--/--/--/-
Sakashu Group
~~~~~~~~~~~~~~
Kochigatani Group
/--/--/--/--/-
Haigyu Group
/--/--/--/--/-
Mitaki Igneous Rocks
/--/--/--/--/-
Miyagadani Metamorphic Rocks
/--/--/--/--/-
[ Lower ]

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

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

Distribution: Hirose - Sakashu - Kamiyochi - Hayashidani - Nakatani, Naka city, Naka county, Tokushima pref.
Fossils (Radiolarians): Parahsuum simplum, Parahsuum ovale, Gigi sp., Bagotum sp.

Hara et al. (2014) Geology of the Kitagawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 72p. (in Japanese with English abstract 4p.)
Ishida (2007) Jour. Geol. Soc. Japan, vol.113, no.3, pp.83-94 DOI