A Alternation of Sandstone and Mudstone Member

A Alternation of Sandstone and Mudstone Akahane, 1975

Type locality: Shiun valley, Nadachi river, Nadachi ward, Joetsu city, Niigata prefecture
Coherent formation
Rift basin sediments
Miocene (13.5 - ? Ma)

Sedimentary facies: Marine
Sedimentary facies: Submarine fan (Sandy radial fan type)
Sedimentary facies: Lower part of the 1st marine regression - transgression sequences
Sedimentary facies: Sandy turbidite
Lithofacies: Sandstone-dominant tnterbedded sandstone and mudstone
Lithofacies (Minor): Sandstone, Mudstone
Sedimentary structures (Shale): Slump structure

Thickness: ca. 200 m
Upper limit: Conformity (B Mudstone Member)

Nambayama Formation
[ Upper ]
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J Alternation of Sandstone and Mudstone
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I Alternation of Sandstone and Mudstone
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H Alternation of Sandstone and Mudstone
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G Shale Member
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F Alternation of Sandstone and Mudstone Member
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E Shale Member
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D Alternation of Sandstone and Mudstone Member
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C Alternation of Sandstone and Mudstone Member
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B Mudstone Member
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A Alternation of Sandstone and Mudstone
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[ Lower ]

Nishikubiki Group
[ Upper ]
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Kawazume Formation
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Nodani Formation
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Nanbayama Formation
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[ Lower ]

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

Distribution: Shiun valley, Nadachi river, Nadachi ward, Joetsu city, Niigata pref.
Fossils (Foraminifera): Globorotalia peripheroronda, Globorotalia quinifalcata

Takano (2011) Jour. Geol. Soc. Japan, vol.117, no.4, pp.238-258 DOI
Akahane and Kato (1989) Geology of the Takada-Seibu District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 89p. (in Japanese with English abstract 3p.)