[ Top ] [ Japanese ]

Yuasa Formation

• Coherent formation
• Yuasa - Aridagawa basin
• Early Cretaceous, Hauterivian

• Sedimentary facies (Upper): Brackish, Terrestrial
• Sedimentary facies (Lower): Terrestrial
• Sedimentary facies (Upper): Fan delta, Fan
• Sedimentary facies (Lower): Fan
• Lithofacies: Interbedded conglomerate, sandstone and mudstone
• Paleocurrent: North to South

• Thickness (North): ca. 30 m
• Thickness (South): 300 m or thicker
• Lower limit: Unconformity (Kurosegawa Belt, Northern Chichibu Belt)

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

• Distribution: Takada seashore, Arida city, Wakayama pref.; Ayame seashore, Yuasa city, Arida county, Wakayama pref.
• Fossils: Brackish shellfish

• Yao (2012) Jour. Geol. Soc. Japan, vol.118, Supplement, pp.90-106 DOI
• Kase and Maejima (2010) Jour. Geol. Soc. Japan, vol.116, no.5, pp.287-290 DOI