Somanakamura Gr
Period:
Jurassic
Age Interval:
Early Jurassic (Bajocian-Tithonian), (8i)
Province:
South Kitakami Belt-Central Sub-belt
Type Locality and Naming
the Karakuwa-Oshika Sub-belt; Soma District
Synonym:
Lithology and Thickness
It comprises the Awazu, Yamagami, Tochikubo, Nakanosawa, Tomizawa and Koyamada formations in ascending order (Yanagisawa et a1. 1996). These units are dominated by clastic rocks. except for the Nakanosawa Fm which includes thick limestone beds.
Lithology Pattern:
Aus conglomerate
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Koyamada Fm
Upper contact
Regionally, the schematic strat column indicates this is the youngest unit.
Regional extent
The Somnakamura Gr, distributed in the Soma district of the Abukuma Massif, also belongs to the Karakuwa-Oshika Sub-belt.
GeoJSON
null
Fossils
Age
Early Jurassic (Bajocian-Tithonian)
Age Span:
Beginning stage:
Bajocian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
170.90
Ending stage:
Kimmeridgian
Fraction up in the ending stage:
1.0
Ending date (Ma):
149.24
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.