[ Top ] [ Japanese ]
Ofuna Formation Otsuka, 1937
Invalid synonym: Ofuna Mudstone Formation
- Sedimentary facies: Marine
- Lithofacies: Massive mudstone
- Lithofacies (Lower Minor): Tuffaceous sandstone
- Thickness: 70 - 190 m
- Upper limit: Conformity (Lithofacies boundary between massive mudstone and upper sandy mudstone)
- Upper limit: Transitional (Koshiba Formation), Unconformity (Naganuma Formation)
- Lower limit: Conformity (Lithofacies boundary between lower muddy sandstone and massive mudstone)
- Lower limit: Transitional (Nojima Formation)
------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown
- Distribution: Ofuna town - Sekiya - Ueki - Okamoto, Kamakura city, Kanagawa pref.; Kamigo town - Suiko - Iwase - Kuden town - Mount Enkaizan - Kitadani - Kamariya town - Yatsu town - Kanazawabunko, Sakae-ku, Yokohama city, Kanagawa pref.
- Fossils (Shellfishes): Acila divaricata, Limopsis tajimae, Lucinoma acutilineatum, Nuculana (Thestyleda) sp., Thyasira nipponica, Turicicula sp., Yoldia naganumana
- Tephra: Kd19, Kd23, O26
- Kusu et al. (2014) Jour. Geol. Soc. Japan, vol.120, no.2, pp.53-70 DOI
- Suzuki and Murata (2011) Jour. Geol. Soc. Japan, vol.117, no.7, pp.379-397 DOI
- Mitsunashi and Kikuchi (1982) Geology of the Yokohama District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 105p. (in Japanese with English abstract 4p.)