Yamanishi Formation

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Yamanishi Formation

Invalid synonym: Nishihara Formation, Sarutani Formation

Type locality: Shiraidani, Tenkawa city, Yoshino county, Nara prefecture
Accretionary complex
Late Cretaceous, Cenomanian (Radiolarians)

Sedimentary facies: Marine
Lithofacies: Shale, Sandstone
Lithofacies (Minor): Greenstones, Felsic tuff, Chert, Limestone

Thickness: 600 - 1,100 m
Upper limit: Conformity (Tsuzurao Formation)
Lower limit: Thrust fault (Tonono Formation)

Tenkawa Subgroup
[ Upper ]
/--/--/--/--/-
Fukatani Formation
--------------
Tsuzurao Formation
--------------
Yamanishi Formation
/--/--/--/--/-
[ Lower ]

Hidakagawa Group (Tenkawa, Nara pref.)
[ Upper ]
/--/--/--/--/-
Heibara Subgroup
/--/--/--/--/-
Nishiyoshino Subgroup
/--/--/--/--/-
Tenkawa Subgroup
/--/--/--/--/-
Uenoji Subgroup
/--/--/--/--/-
Hiradani Subgroup
/--/--/--/--/-
[ Lower ]

Shimanto Belt (Nara pref.)
[ Upper ]
/--/--/--/--/-
Koyasan Group = North Shimanto
/--/--/--/--/-
Hidakagawa Group = North Shimanto
/--/--/--/--/-
Hikigawa Group = South Shimanto
/--/--/--/--/-
[ Lower ]

Shimanto Belt (Wakayama pref.)
[ Upper ]
/--/--/--/--/-
Koyasan Group = North Shimanto
/--/--/--/--/-
Hidakagawa Group = North Shimanto
/--/--/--/--/-
Nyunokawa Formation
/--/--/--/--/-
Otonashigawa Group
/--/--/--/--/-
Muro Group
/--/--/--/--/-
[ Lower ]

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

Distribution: Shiraidani - Tennokawa river, Tenkawa city, Yoshino county, Nara prefecture
Fossils (Radiolarians): Dictyomitra duodecimcostata, Dictyomitra pseudomacrocephara, Mirifusus sp., Protunuma cf. brouweri

Shiida et al. (1989) Geology of the Sanjogatake District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 100p. (in Japanese with English abstract 5p.)