Middle Cenomanian–Turonian sequence stratigraphy of central-southern Tunisia: regional and global control on depositional patterns

The identification of depositional sequences in the Upper Cretaceous stratigraphic record of central-southern Tunisia constitutes a key to recognize the main events steering the evolution of carbonate platforms occurring in the study area and at other localities of the African Tethyan margin. The sequence stratigraphic analysis of the middle Cenomanian–Turonian series was calibrated by detailed lithofacies analysis and biostratigraphic data and revealed six third-order depositional sequences (S1, S2, S3, S4, S5, and S6) covering a period of about 3.7 million years. These sequences are bounded by seven major unconformities (SB Ce4, SB Ce5, SB2, SB Tu1, SB Tu2, SB Tu3, and SB Tu4) that occur throughout central-southern Tunisia and are of regional importance throughout the Tethyan realm. The timing of the middle Cenomanian–Turonian depositional sequences reveals that some of the studied sequences (S1, S3, and S6) match with those documented in North Africa and Europe, while others show a clear mismatch (S2, S4, and S5). These differences could be related to sea-level changes and/or syn-depositional extensional tectonic movements controlling the creation and infill of accommodation space during the deposition of the (upper Cenomanian?) – lower Turonian Gattar platform and the lower–middle Turonian Biréno platform sediments.