Yuantani Formation

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Yuantani Formation Ishida et al., 1954

The official name of the type locality is 'Yuyadani' but the name of strata is 'Yuantani'.

Type locality: Okuyamada, Ujitawara city, Tsuzuki county, Kyoto prefecture
Coherent formation
First Seto Inland Sea
Sedimentary basin in island arc
middle Miocene

Sedimentary facies: Marine
Lithofacies (Upper): Conglomerate
Lithofacies (Lower): Sandstone
Lithofacies (Lower, Minor): Conglomerate

Thickness: 150 m or thicker
Lower limit: Bottom of the conglomerate-intercalating horizen overlying mudstone-dominant horizon
Lower limit: Conformity (Okuyamada Formation)

Yuantani Formation
[ Lower ]
~~~~~~~~~~~~~~
Tahara Member
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Shiodani Member
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[ Upper ]

Tsuzuki Group
[ Upper ]
~~~~~~~~~~~~~~
Yuantani Formation
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Okuyamada Formation
~~~~~~~~~~~~~~
[ Lower ]

First Setouchi Supergroup (Kyoto pref.)
[ Upper ]
~~~~~~~~~~~~~~
Tsuzuki Group
~~~~~~~~~~~~~~
[ Lower ]

[ Upper ]
~~~~~~~~~~~~~~
Second Setouchi Supergroup
?--?--?--?--?-
First Setouchi Supergroup
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Okuyamada - Okuyamadagawa river - Yuyadani - Chaya tunnel, Ujitawara city, Tsuzuki county, Kyoto pref.
Fossils (Shellfishes): Anadara sp., Katelysta nakamurai, Protorotella yuantaniensis, Prototella sp.

Wakita et al. (2013) Geology of the Kyoto-Tonambu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 124p. (in Japanese with English abstract 3p.)