Sedimentology and Sequential Interpretation of the Fluvio-marine Facies of the “Bejaoua Facies”, Northern Tunisia

The Oligo-Miocene “Bejaoua Facies” Formation of Northern Tunisia can be arranged in three distinct parts which include from base to top: (1) A fully marine system characterizing the lower part (Oligocene) which is well documented at Jebel Hajra Touila , Sidi M’Himech and Touiref settings. (2) An alluvial fan, shallow marine and fluvial deposits characterize the middle part (Aquitanian)respectively in Sidi M’Himech, Hajra Touila and Touiref sections. (3) The Upper Part (Aquitanian) shows a fully fluvial system consisting of braided stream channel sandstones common to all sections. This subdivision was based (1) on sequential interpretation including a key stratal surfaces ( unconformities,Sequences boundaries SB and Maximum Flooding Surface MFS) of facies stacking patterns occur in Bejaoua Facies Formation (2)on eventuel chronostratigphic correlation with Fortuna Formation which is bounded above and below by biostratigraphically dated key strata.