Minakuchi Alternation of Sandstone and Mudstone Member

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Minaguchi Alternation of Sandstone and Mudstone Member Akahane, 1975

Type locality: Kuwatori river, Minakuchi, Kuwatori, Joetsu city, Niigata prefecture
Coherent formation
Rift basin sediments
Miocene (5.3? - 5 Ma)
Lower: Miocene (6.5 - 5.3? Ma)
Bottom: Miocene (6.5 Ma)
Correlation: Upper Teradomari Formation, Sennozawa Formation

Sedimentary facies: Marine
Sedimentary facies: Submarine fan (Muddy channel levee system type)
Lithofacies: Muddy turbidite
Lithofacies: Mudstone-dominant interbedded sandstone and mudstone
Lithofacies (Minor): Mudstone, Sandstone

Thickness: 400 - 600 m
Upper limit: Conformity (Nakanomata Mudstone Member)
Lower limit: Conformity (Yokobatake Alternation of Sandstone and Mudstone Member)

Minakuchi Alternation of Sandstone and Mudstone Member
[ Upper ]
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Kanaya Tuff Member
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[ Lower ]

Nodani Formation
[ Upper ]
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Nakanomata Mudstone Member
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Minakuchi Alternation of Sandstone and Mudstone Member
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Yokobatake Alternation of Sandstone and Mudstone Member
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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: Kuwatori river, Minakuchi, Kuwatori, Joetsu city, Niigata pref.; Utsuo - Kamitsunako - Nakanomata - Higashihiyama, Joetsu city, Niigata pref.; Nishihiyama - Maseguchi - Hayakawa river, Itoigawa city, Niigata pref.
Fossils: Shell fragments, Pipe rocks

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.)