S2a Fm
Period:
Tonian
Age Interval:
764–804 Ma
Province:
West Congo Basin / Bas-Congo region, DRC
Type Locality and Naming
Synonym:
Reference section:
Lithology and Thickness
fine grained quartzite, purple psammite and siliceous shale in the lower part; whitish to greyish grained feldspathic quartzite with many interbedded cherts, frequently oolitic or stromatolitic Thickness: ≤ 875 m.
Lithology Pattern:
Fine-grained sandstone
Relationships and Distribution
Lower contact
Underlain by the S1 Fm.
Upper contact
Overlain by the S2b Fm.
Regional extent
West Congo Belt (DRC, Republic of Congo, Gabon, NW Angola).
GeoJSON
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Fossils
Age
Interpolated by thickness (54.5%) between 750–850 Ma
Age Span:
Beginning stage:
Tonian
Fraction up in beginning stage:
0.84
Beginning date (Ma):
764.80
Ending stage:
Tonian
Fraction up in the ending stage:
0.70
Ending date (Ma):
804.00
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Cailteux, J.L.H., Delpomdor, F.R.A., & Ngoie Ndobani, J.-P. (2015). The Neoproterozoic West-Congo 'Schisto-Calcaire' sedimentary succession from the Bas-Congo region (Democratic Republic of the Congo) in the frame of regional tentative correlations. Geologica Belgica, 18/2-4, 126–146.