Planktic foraminiferal biostratigraphy, paleoecology and chronostratigraphy across the Eocene/Oligocene boundary in northern Tunisia

Abstract

The Eocene-Oligocene (E-O) transition was an epoch of great turnover, in both terrestrial and marine environments. Mammals were highly affected by an extinction event called grande coupure of Stehlin, which has been very well documented in Europe and Asia (Hartenberger, 1998). In America the tropical molluscs underwent a significant extinction event at the beginning of the Oi-1 glaciation in the Oligocene (Hickman, 2003). This drop in temperature was caused by the opening of the Drake Strait, thereby giving rise to the circum Antarctic current, the formation of ice caps on the poles and the development of the psychrosphere in

The Eocene‐Oligocene Transition in the South‐Western Neo‐Tethys (Tunisia): Astronomical Calibration and Paleoenvironmental Changes

“…Stratigraphic distribution of selected calcareous nannofossil taxa along with biostratigraphic zones. On the right, a lithostratigraphic correlation between El Rahma section (this study) and Menzel Bou Zelfa section (Karoui-Yaakoub et al, 2017) is presented and allows for positioning the Eocene/ Oligocene boundary (top hantkeninids at Menzel Bou Zelfa). The identified species are reported with lines of different thicknesses corresponding to their semiquantitative abundance (VR ¼ very rare; R ¼ rare; F ¼ frequent).…”

“…There can be considerable confusion in the taxonomy of elliptical placoliths of Reticulofenestra and Dictyococcites, two reticulofenestrid genera that strongly overlap in size and placolith circularity (Henderiks & Pagani, 2008). Planktic Foraminiferal (PF) biostratigraphy is after Karoui-Yaakoub et al (2017) on the Menzel Bou Zelfa composite section (3 km northeast of the El Rahma section) and can be easily correlated to our section by lithostratigraphy using the similarity of facies and prominent limestone beds (Figure 2).…”

“…Central Italy represents the most studied area of the northwestern margin of the Neo-Tethys (e.g., Brown et al, 2009;Hyland et al, 2009;Jovane et al, 2007), and one study has recently focused on the central Paratethys (Ozsvárt et al, 2016). So far, only two published works have focused on the Southern Neo-Tethys documenting the detailed stratigraphy and the expression of the Eocene/Oligocene climatic transition based on foraminiferal assemblages (Grira et al, 2018;Karoui-Yaakoub et al, 2017).…”

“…On-land outcrop studies of middle-to low-latitude sites are also essential in paleoenvironmental and paleoclimatic modeling in order to better understand the differential expression of major climatic events in Earth's history. Northeastern Tunisia (Cap Bon peninsula) hosts scenic exposures of strata spanning the middle Eocene to present-day deposits and offers continuous and well-preserved outcrops suitable for such high-resolution studies (Burollet, 1956;Grira et al, 2018;Karoui-Yaakoub et al, 2017;Yaich et al, 1994). In order to report the paleoenvironmental and paleoclimatic changes in response to the Eocene/Oligocene greenhouse-icehouse transition and to retrieve the sedimentary expression of Milankovitch cycles across this major glaciation event, an integrated approach including new stratigraphic data (CNs, cyclostratigraphy, and carbon isotope stratigraphy) as well as XRF elemental data has been performed in a marine succession (lower bathyal-abyssal to shallow shelf facies) covering the late Eocene-early Oligocene interval in the Cap Bon peninsula.…”

Paleoenvironmental and ecological changes during the Eocene-Oligocene transition based on foraminifera from the Cap Bon Peninsula in North East Tunisia

“…The biostratigraphy of this section was previously studied and published by the present authors (Karoui-Yaakoub et al, 2017) with planktic foraminifera biozonation based on Pearson et al (2006). The last occurrence (LO) of the index taxon Globigerinatheka semiinvoluta was used to recognize E14, the LO of Globigerinatheka index to mark E15, the…”