Tomizawa 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 Tochikubo Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Nakanosawa Fm
Regional extent
GeoJSON
null
Fossils
Age
Shown as Middle Jurassic-Early Cretaceous, hence placed 50% up in Callovian
Age Span:
Beginning stage:
Callovian
Fraction up in beginning stage:
0.5
Beginning date (Ma):
163.41
Ending stage:
Oxfordian
Fraction up in the ending stage:
1.0
Ending date (Ma):
154.78
Depositional setting
The Tomizawa Formation has been interpreted as an alluvial deposit (Takizawa 1985).
Depositional pattern:
Additional Information
Compiler:
Moreno, T., WALLIS, S., Kojima, T. & Gibbons, W. (Eds) 2016. The Geology of Japan. Geological Society. London. 1-24.