Okunikko Rhyolites

Invalid synonym: Irohazaka Welded Tuff

Volcanic rocks
Cretaceous - Paleogene (61.6 Ma, FT; 65, 56 Ma, K-Ar, 63.4 Ma, Rb-Sr)
Correlation: Yorii Welded Tuff

Lithofacies: Rhyolitic pyroclastic rocks

Okunikko Rhyolites
[ Upper ]
~~~~~~~~~~~~~~
Nagahata Acidic Rocks
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Irohazaka, Nikko city, Tochigi pref.

Yoshikawa et al. (2010) Geology of the Utsunomiya District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 79p. (in Japanese with English abstract 6p.)