Niwaya Formation

Type locality: Tomioka city, Gunma prefecture
Coherent formation
Miocene

Sedimentary facies: Marine

Upper limit: Conformity (Haraichi Formation)
Lower limit: Unconformity (Tomioka Group)

Annaka Group
[ Upper ]
~~~~~~~~~~~~~~
Itahana Formation
--------------
Haraichi Formation
--------------
Niwaya Formation
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Tomioka city, Gunma pref.

Tanaka et al. (2013) Jour. Geol. Soc. Japan, vol.119, no.1, pp.17-24 DOI