Heibara Subgroup

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Heibara Subgroup

Invalid synonym: Yoshinoyama Group, Yoshinoyama zone

Formerly interpreted as a part of Sanbagawa Metamorphic Rocks

Type locality: Momijigawa river, Heibara, Shimoichi city, Yoshino county, Nara prefecture
Accretionary complex
Early Cretaceous (Radiolarians)

Sedimentary facies: Marine
Metamorphic facies: High P/T
Lithofacies: Slate, Phyllite
Lithofacies (Minor): Sandstone, Greenstones, Chert
Lithofacies (Protolith): Shale
Lithofacies (Protolith, Minor): Sandstone, Greenstones, Chert

Thickness: 1,500 m or thicker
Lower limit: Thrust fault (Karato Tectonic Line, Nishiyoshino Subgroup)

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: Heibara - Momijigawa river - Awaitani - Ishidodani - Nashido - Shimizu, Shimoichi city, Yoshino county, Nara pref.; Otaki, Kawakami city, Yoshino county, Nara pref.
Fossils (Radiolarians): Archaeodictyomitra cf. praevenata, Dictyomitra cf. carpatica

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.)
Hirayama and Kishimoto (1957) Yoshinoyama, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 44p. (in Japanese with English abstract 8p.)