Clay mineralogical distribution and tectono-eustatic control in the Tunisian margin basins

We have studied the clay assemblages found in the different palaeogeographic domains located at the several Tunisian margin basins, ranging in age from Palaeozoic to Neogene. This study has allowed us to characterize and highlight the relationship between the clay distribution in time and space and the geodynamic and eustatic events. Marine regressions, with the intensification of erosion, seem to be responsible for illite increases, whereas transgressions, in concordance with a warm and dry climate, coincide with the smectite dominance. The minimum marine level coincides with the abundance of palygorskite. Mineralogic changes in the clay assemblages as well as in the proportion of the different clay minerals will tentatively be related to erosive tectonic events and/or to subsiding and rifting events, marked by the inheritance or the neoformation of the several clays. [Copyright &y& Elsevier]