- © 2011 Geological Society of South Africa
A new site containing stromatolite-bearing silicified carbonates horizons is described in the Nsuze Group within the Nkandla Basin of the Pongola Supergroup. The stromatolite-bearing carbonate units are interbedded with calcareous arenite and represent stratiform biostromes exhibiting both smooth and wrinkled laminations. Microbially-accentuated current ripples are regularly preserved upon stratiform stromatolitic substrates. The recognition of these stromatolite-bearing units in a previously undifferentiated Nsuze Group succession not only increases the area in which these accretionary, organo-sedimentary structures have been identified, but more importantly can provide the basis for regional lithostratigraphic correlation between the relatively well-defined stratigraphy of the main Pongola Basin and the more deformed and much less well-defined sequences in the structurally complex Nkandla Basin. The improved understanding of the regional stratigraphy generated by the recognition of this stromatolite-bearing marker horizon will provide a fundamental factor in deciphering the relationships of Pongola Supergroup inliers and the tectonic development of the region during the Mesoarchaean.