Oshima Gr
Period:
Cretaceous
Age Interval:
Early Cretaceous (Hauterivian-Aptian), (8h)
Province:
South Kitakami Belt-Central Sub-belt
Type Locality and Naming
the Karakuwa-Oshika Sub-belt
Synonym:
Lithology and Thickness
It comprises the Kanaegaura and overlying Yokonuma formations (Onuki I969).
Lithology Pattern:
Volcanic_ash
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Kanaegaura Fm
Upper contact
Regionally, the schematic strat column indicates this is the youngest unit
Regional extent
The Oshima Group mostly crops out on Oshima Island. In the Karakuwa district of the Karakuwa-Oshika Sub-belt, Mesozoic rocks are represented by the Karakuwa Group and the Oshima Group within the wide, south-plunging Tsunakizaka Syncline.
GeoJSON
null
Fossils
Age
Early Cretaceous (Hauterivian-Aptian)
Age Span:
Beginning stage:
Hauterivian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
132.60
Ending stage:
Albian
Fraction up in the ending stage:
1.0
Ending date (Ma):
100.50
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Moreno, T., WALLIS, S., Kojima, T. & Gibbons, W. (Eds) 2016. The Geology of Japan. Geological Society. London. 1-24.