Emi Formation

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Emi Formation (Kawai, 1957) Nakajima et al., 1981

Type locality: Emi, Kamogawa city, Chiba prefecture
Accretionary complex
middle Miocene (Nannofossils)
Correlation: Masuma Formation, Kohama Formation, Kinone Formation

Sedimentary facies: Marine
Water temperature: Warm ocean current
Lithofacies: Shale, Mudstone
Lithofacies (Minor): Sandstone, Tuff
Sedimentary structures: Parallel stratification

Thickness: ca. 90 - 240 m
Lower limit: Conformity (Nabuto Formation)

Hota Group (Western part)
[ Upper ]
~~~~~~~~~~~~~~
Ezuki Formation
--------------
Tomiyama Formation
--------------
Aokiyama Formation
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Masuma Formation
::::::::::::::
[ Lower ]

Hota Group (Eastern part)
[ Upper ]
~~~~~~~~~~~~~~
Emi Formation
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Nabuto Formation
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Takazuru Formation
--------------
Furubo Formation
~~~~~~~~~~~~~~
[ Lower ]

Mineoka Belt (Boso peninsula)
[ Upper ]
~~~~~~~~~~~~~~
Awa Group / Minamiboso Group
~~~~~~~~~~~~~~
Hota Group
::::::::::::::
Mineoka Group
?--?--?--?--?-
[ Lower ]

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

Distribution: Emi - Ichiihara, Kamogawa city, Chiba pref.
Fossils: Diatoms
Fossils (Silicoflagellates): Cannopilus hemisphaericus, Corbisema triacantha, Dictyocha fibula, Distephanus crux, Distephanus speculum, Distephanus speculukm var. cannopiloides, Distephanus speculum var. pentagonus, Macrora stella

Takahashi et al. (2016) Jour. Geol. Soc. Japan, vol.122, no.8, pp.375-395, DOI
Nakajima et al. (1981) Geology of the Kamogawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 107p. (in Japanese with English abstract 7p.)