Microbial influence in the Messinian sedimentation: Example of Cap Bon (NE Tunisia)

Abstract

Messinian sedimentation in Tunisia is characterized by the absence of large carbonate platforms known in many Mediterranean marginal basins. As a result, correlations are not easy to establish in order to integrate it into a general pattern of development at the regional level. However, the discovery of microbial constructions of metric scale makes it possible to precise uncertain points. Thus in the sector of Cap Bon in the northeast of Tunisia, stromatolitic constructions can form, over distances of several hundred meters, domes containing columnar structures at different scales as well as carbonate beds showing sedimentary ripples also of microbialite nature. The highlighting of an assemblage of microbialites, associated with oolitic deposits, allows linking these formations to the Terminal Carbonate Complex which finds its place at a part of the so-called Messinian Salinity Crisis.