Kojima Fm
Period:
Jurassic
Age Interval:
Middle Jurassic (Bajocian), (8g)
Province:
South Kitakami Belt-Western Sub-belt
Type Locality and Naming
Shizugawa (Shizukawa)-Hashiura Sub-belt; Mizunuma area
Synonym:
Lithology and Thickness
It consists mainly of arkose in association with conglomerate and alternating beds of sandstone and mudstone
Lithology Pattern:
Sandstone
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Saragai Gr
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Owada Fm
Regional extent
Shizugawa (Shizukawa)-Hashiura Sub-belt; Mizunuma area. Coeval with Aratozaki Fm; Nakahara Fm
GeoJSON
null
Fossils
Age
Shown as Middle Jurassic-Early Cretaceous, hence placed Base of Bajocian
Age Span:
Beginning stage:
Bajocian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
170.90
Ending stage:
Bajocian
Fraction up in the ending stage:
0.5
Ending date (Ma):
169.54
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.