[ Top ] [ Japanese ]

Orojidani Formation Nagata et al., 2015

• Type locality: Oroji valley, Tanohara, Yoshika city, Kanoashi county, Shimane prefecture
• Coherent formation
• Early Jurassic, Hettangian - Sinemurian ? (Bivalves)

• Sedimentary facies: Marine
• Depth of water: Shallow
• Lithofacies: Repeated upward-fining units of conglomerate-sandstone-mudstone
• Sedimentary structures: Current ripples, Cross stratification, Parallel stratification, Flaser bedding, Bioturbation

• Thickness (1 unit): 4 - 18 m
• Thickness (Overall): 180 - 400 m
• Upper limit: Conformity
• Lower limit: Uncnformity (Nishiki Group)

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

• Distribution: Higuchi valley, Muikaichi, Yoshika city, Kanoashi county, Shimane pref.; Oroji valley, Kinzan valley, Tanohara, Yoshika city, Kanoashi county, Shimane pref.; Kanoashigochi river, Yoshika city, Kanoashi county, Shimane pref.
• Fossils (Bivalves): Oxytoma sp., Pleuromya sp.

• Nagata et al. (2015) Jour. Geol. Soc. Japan, vol.121, no.2, pp.59-69 DOI