Nakahata Fm
Period:
Devonian
Age Interval:
Pragian, (15a)
Province:
Kurosegawa Belt- Shikoku
Type Locality and Naming
Kurosegawa Belt-central Shikoku
Synonym:
Lithology and Thickness
Dominated by acidic tuff and tuffaceous sandstone, including basal conglomerate-sandstone with abundant granite, rhyolite and acidic tuff clasts.
[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:
Volcanic_ash
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Ichiyama Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Ochi Fm
Regional extent
Kurosegawa Belt-central Shikoku
GeoJSON
null
Fossils
This formation yields an abundant radiolarian fauna
Age
Shown as middle Early Devonian- early Middle Devonian, hence placed Base of Pragian
Age Span:
Beginning stage:
Pragian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
412.40
Ending stage:
Emsian
Fraction up in the ending stage:
1.0
Ending date (Ma):
394.30
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.