Joryu Fm
Period:
Silurian
Age Interval:
Pridolian (Pridoli), (19a)
Province:
Kurosegawa Belt- Shikoku
Type Locality and Naming
Kurosegawa Belt-central Shikoku
Synonym:
Lithology and Thickness
Consists of conglomerate in the lower part and tuffaceous sandstone, acidic tuff and conglomerate in the upper part.
[Figure 1: Stratigraphy of the Paleozoic of the Kurosegawa Belt in the central part of Shikoku, Southwest 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 Fukata Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Ichiyama Fm
Regional extent
Kurosegawa Belt-central Shikoku
GeoJSON
null
Fossils
The acidic tuff contains rich Pridolian radiolarians (Umeda 1998b, c).
Age
Shown as Pridolian, hence placed Base of Pridoli
Age Span:
Beginning stage:
Pridoli
Fraction up in beginning stage:
0.0
Beginning date (Ma):
422.73
Ending stage:
Pridoli
Fraction up in the ending stage:
1.0
Ending date (Ma):
419.00
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.