Koyama Formation

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Koyama Formation

Coherent formation
Cretaceous

Sedimentary facies: Terrestrial
Lithofacies: Sandstone
Lithofacies (Minor): Shale
Lithofacies (Basal): Conglomerate

Thickness: 100 - 150 m
Upper limit: Conformity (Nagasaki Formation)
Lower limit: Unconformity (Nagaiso Formation)

Massaki Group
[ Upper ]
?--?--?--?--?-
Nagasaki Formation
--------------
Koyama Formation
~~~~~~~~~~~~~~
[ Lower ]

Ofunato Subelt
[ Upper ]
?--?--?--?--?-
Massaki Group
~~~~~~~~~~~~~~
Ofunato Group
?--?--?--?--?-
[ Lower ]

South Kitakami Belt (after Permian)
[ West ]
::::::::::::::
Shizukawa-Hashiura Subbelt
::::::::::::::
Karakuwa-Oshika Subbelt
::::::::::::::
Ofunato Subelt
::::::::::::::
[ East ]

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

Distribution: Iwate pref.

Kambe and Shimazu (1961) Kesennuma, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 73p. (in Japanese with English abstract 16p.)