Sh1 Fm
Period:
Cryogenian
Age Interval:
687–694 Ma
Province:
West Congo Basin / Bas-Congo region, DRC
Type Locality and Naming
Synonym:
Reference section:
Lithology and Thickness
sandy-calcareous matrix supported conglomerate and quartzite. Basal unit of Haut-Shiloango Subgroup.
Lithology Pattern:
Aus conglomerate
Relationships and Distribution
Lower contact
Underlain by the Lower Diamictite (former 'Mixtite') Fm.
Upper contact
Overlain by the Sh2 Fm.
Regional extent
West Congo Belt (DRC, Republic of Congo, Gabon, NW Angola).
GeoJSON
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Fossils
Stromatolites (in Sekelolo limestones).
Age
U-Pb baddeleyite age 694 ± 4 Ma from Sumbi-type dolerite sill. "The Haut-Shiloango is therefore considered to be deposited in a time-interval between 694 ± 4 Ma and the ca. 635 Ma Marinoan age Upper Diamictite Formation."
Age Span:
Beginning stage:
Cryogenian
Fraction up in beginning stage:
0.39
Beginning date (Ma):
686.85
Ending stage:
Cryogenian
Fraction up in the ending stage:
0.31
Ending date (Ma):
693.65
Depositional setting
Post-Sturtian open marine carbonate platform; two transgression-regression cycles (Cahen, 1954; Frimmel et al., 2006).
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.