[ Top ] [ Japanese ]
Haraichi Formation (Ishiwada, 1948) Takayanagi et al., 1978
Invalid synonym: Yoshii Formation
- Type locality: Usui river, Yanasekubo - Shimoisobe, Annaka city, Gunma prefecture
- Coherent formation
- middle Miocene (- ca. 11 Ma, Foraminifera, Radiometric dating)
- Sedimentary facies: Marine
- Depth of water: Bathyal (Foraminifera)
- Lithofacies: Siltstone
- Lithofacies (Minor): Conglomerate, Sandstone, Tuff
------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown
- Distribution: Usui river, Yanasekubo - Shimoisobe - Matsuida, Annaka city, Gunma pref.
- Fossils: Whales (Skull), Birds (Swan), Sharks (Carcarodon sp., Isurus sp.), Fishes, Shellfishes (12 species)
- Tephra: Kitamura Tuff, Baba Tuff
- Tanaka et al. (2013) Jour. Geol. Soc. Japan, vol.119, no.1, pp.17-24 DOI
- Geshi and Takeuchi (2012) Geology of the Haruna San District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 79p. (in Japanese with English abstract 3p.)