Kobosoura Fm
Period:
Cretaceous
Age Interval:
Early Cretaceous (Hauterivian), (8k)
Province:
South Kitakami Belt-Eastern Sub-belt
Type Locality and Naming
the Ofunato Sub-belt
Synonym:
Lithology and Thickness
It consists of pyroclastic rocks, tuffaceous sandstone and conglomerate with intercalated sandstone and mudstone
Lithology Pattern:
Metavolcanics
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Hakoneyama Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Funagawara Fm
Regional extent
GeoJSON
null
Fossils
It contains the bivalve Pterotrigonia (Pterotrigonia) dated as Hauterivian-Aptian (Tashiro & Kozai 1989).
Age
Early Cretaceous (Hauterivian)
Age Span:
Beginning stage:
Hauterivian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
132.60
Ending stage:
Hauterivian
Fraction up in the ending stage:
0.2
Ending date (Ma):
131.38
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.