Orikabeloge Fm
Period:
Silurian
Age Interval:
Middle Silurian (Homerian), (8b)
Province:
South Kitakami Belt- Miyamori-Hayachine-Kamaishi district
Type Locality and Naming
Synonym:
Lithology and Thickness
It is composed of conglomerate, arkose and mudstone with subordinate amounts of limestone and tuff, and a rich fauna of Silurian corals and trilobites (Okami et al., 1986). The conglomerate contains many granitic clasts lithologically similar to those exposed in the Hikami granitic complex of the Hikoroichi-Setamai district (see figure 1).
[Figure 1: Stratigraphy of the Palaeozoic of the South Kitakatmi Belt, NE Japan (after M. Ehiro et al., 2016)]
Lithology Pattern:
Aus Conglomerate
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Odagoe Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Senjyogataki Fm
Regional extent
GeoJSON
null
Fossils
Age
Shown as Middle Silurian, hence placed Base of Homerian
Age Span:
Beginning stage:
Homerian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
430.62
Ending stage:
Gorstian
Fraction up in the ending stage:
1.0
Ending date (Ma):
425.01
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.