Nakano Formation

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Nakano Formation

Type locality: Nakano, Onan city, Ochi county, Shimane prefecture
Volcanic rocks
middle Eocene (ca. 40 Ma; 58, 40.6, 36.5 Ma, FT)
Intruded by: Kawamoto body, Mihara body

Lithofacies: Hornblende biotite rhyolite - dacite welded tuff

Thickness: ca. 400 m
Distribution (East - West): ca. 30 km
Distribution (South - North): ca. 14 km
Lower limit: Conformity, partly unconformity (Takahoriyama Formation)

Sakurae Group
[ Upper ]
~~~~~~~~~~~~~~
Nakano Formation
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Takahoriyama Formation
~~~~~~~~~~~~~~
[ Lower ]

Tamagawa stage volcanic rocks (Shimane pref.)
[ Young ]
~~~~~~~~~~~~~~
Sakurae Group
~~~~~~~~~~~~~~
Kotani Formation
~~~~~~~~~~~~~~
Kawamoto Granodiorite
~~~~~~~~~~~~~~
Komatsuji Formation
~~~~~~~~~~~~~~
Toburodani Formation
~~~~~~~~~~~~~~
[ Old ]

Sanin Belt
[ Young ]
~~~~~~~~~~~~~~
Tamagawa stage volcanic rocks
~~~~~~~~~~~~~~
Younger Inbi stage intrusive rocks
?--?--?--?--?-
Older Inbi stage intrusiv rocks
?--?--?--?--?-
Inbi stage volcanic rocks
~~~~~~~~~~~~~~
Mochigase stage intrusive rocks
?--?--?--?--?-
Mochigase stage volcanic rocks
~~~~~~~~~~~~~~
[ Old ]

------ Transitional, ~~~~~~ Intrusive, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

Distribution: Nakano, Onan city, Ochi county, Shimane pref.; Ichinomaru - Inugatani, Kawamoto city, Ochi county, Shimane pref.; Sakurae town, Gotsu city, Shimane pref.; Asahi town, Hamada city, Shimane pref.

Kano et al. (2001) Geology of the Yunotsu and Gotsu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 129p. (in Japanese with English abstract 5p.)
Matsuura (1990) Geology of the Akana District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 73p. (in Japanese with English abstract 5p.)