(Invalid name) Naka Group

Nakaminato Group and Oarai Formation are not considered as a series of strata.

Coherent formation
Late Cretaceous

Sedimentary facies: Marine

(Invalid name) Naka Group
[ Upper ]
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Nakaminato Formation = Nakaminato Group
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Oarai Formation
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[ Lower ]

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

Distribution: Nakaminato - Oarai, Hitachinaka city, Ibaraki pref.

Sakamoto et al. (1972) Geology of the Nakaminato District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 94p. (in Japanese with English abstract 5p.)