Tochikubo Fm
Period:
Jurassic
Age Interval:
Middle Jurassic (Callovian), (8i)
Province:
South Kitakami Belt-Central Sub-belt
Type Locality and Naming
the Karakuwa-Oshika Sub-belt; Soma District
Synonym:
Lithology and Thickness
It is dominated by clastic rocks
Lithology Pattern:
Aus conglomerate
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Yamagami Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Tomizawa Fm
Regional extent
GeoJSON
null
Fossils
The Tochikubo Formation is of particular interest in yielding a rich flora of Ryoseki-type plants (Kimura & Ohana 1989a, b; Takimoto et a1., 2008)
Age
Shown as Middle Jurassic-Early Cretaceous, hence placed Base of Callovian
Age Span:
Beginning stage:
Callovian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
165.29
Ending stage:
Callovian
Fraction up in the ending stage:
0.5
Ending date (Ma):
163.41
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.