Neoproterozoic diamictites from the Itombwe Synclinorium, Kivu Province, Democratic Republic of Congo: Palaeoclimatic significance and regional correlations

The Itombwe Synclinorium in the Kivu Province of the Democratic Republic of Congo contains a Neoproterozoic succession of greenschist facies metasedimentary rocks defined as the Itombwe Supergroup, dated between 1020 ± 50 and 575 ± 83 Ma. The Itombwe Supergroup unconformably overlies the Mesoproterozoic Kibaran belt and is subdivided into the Upper and Lower Kadubu Groups which are separated by a faulted tectonic contact. Graded, rhythmically repeated sequences of sandstones, greywackes, phyllites and shales indicate deposition as turbiditic sediment-gravity flows. Periods of basin anoxia are indicated by the presence of graphitic black shales. The Lower and Upper Kadubu Groups contain three stratigraphic levels of diamictites and lonestone-bearing iron-rich sedimentary rocks interpreted as glaciogenic strata, which broadly correlate with other Neoproterozoic glacial sequences in the Central African region and elsewhere around the world. Current stratigraphic and geochronological knowledge of these beds is insufficient to provide more accurate correlations.