Wave influences in contemporary and Mesoarchaean stromatolites

Abstract Contemporary shore platform stromatolites (SPS) are becoming well known. We describe the physical environment and macrostructures from contemporary shore platform stromatolites (SPS) on the wave-dominated southeast African coast. This was then compared with Mesoarchaean (2.97 Ga) stromatolites from White Umfolozi (100 km inland). We use the Tinley Manor SPS occurrence as the basis for physical environmental comparison, but where necessary draw on evidence from other SPS environments. SPS and Mesoarchean Umfolozi stromatolites contain similar stromatolitic structures and wave deposits. The SPS environment is wave dominated and the occurrence of similar sedimentary structures associated with the Mesoarchean Umfolozi Stromatolites indicates a paleoenvironment associated with waves. The contemporary Tinley Manor SPS wave climate is robust and from this locality we have identified broad limits in which SPS can develop and be preserved. Applying this knowledge to the Mesoarchaean White Umfolozi stromatolites suggests that they formed in a protected wave climate where wave incursions were less frequent. Both these wave-influenced settings are/were subject to very-low siliciclastic-input. The frequency of marine sediment input appears to be a limiting factor on microbialite growth in both the contemporary SPS and Archaean examples.