[ Top ] [ Japanese ]

Tatsukushi Formation

• Coherent formation
• Miocene

• Sedimentary facies: Marine, Terrestrial
• Sedimentary facies (Upper): Tidal flat near an estuary, Braided river
• Sedimentary facies (Lower): Offshore-transition, Offshore
• Depth of water (Lower): Fair-weather and storm wave dominant shallow
• Lithofacies (Upper): Sandstone
• Lithofacies (Lower): Sandstone
• Sedimentary structures (Upper): Parallel stratification, Hummocky cross-stratification, Trough cross-stratification, Wave-formed ripples
• Sedimentary structures (Lower): Trough cross-stratification (Set height > 1.0 m), Flaser stratification, Wavy stratification, Double mud drapes, Inclined heterolithic stratification

• Upper limit: Unknown
• Lower limit: Conformity

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

• Distribution: Tsumajiro - Tatsukushi, Tosashimizu city, Kochi pref.
• Fossils (Trace fossils): Phycosiphon incertum (Small worms), Lockeia siliquaria (Bivalves), Ophiomorpha isp. (Decapoda)
• Fossils (Trace fossils, Upper): Dactyloidites ottoi (Worms), Macaronichnus isp. (Ragworms), Scolicia isp. (Echinoids)
• Fossils (Trace fossils, Lower): Ophomorpha borneesis, Macaronichnus segregatis degiberti

• Nara et al. (2017) Jour. Geol. Soc. Japan, vol.123, no.7, pp.471-489 DOI