Middle to Upper Eocene ostracofauna of central Tunisia and Pelagian Shelf: examples of Jebel Bargou and the Gabes Gulf

Abstract

Studies on ostracofauna gathered from the Middle–Late Eocene outcropping series of Jebel Bargou anticline, central Tunisia and from an offshore well in the Pelagian Shelf (ABR1) allowed to date major biostratigraphic limits and contribute to improve the precision on the present Eocene biozonation scheme based specially on the planktonic foraminifera markers. Paleogeographic and paleoecological interpretation was derived from an analysis of 60 ostracod species belonging to 38 genera coupled to lithostratigraphic facies interpretation. Ostracods associations indicate an evident similarity between the studied sections with circalittoral taxonomic dominance. In large scale, the ostracofauna recognized in the studied sections shows plentiful similarities with those of Northern Africa and the Middle East regions (Libya, Mauritania, Egypt, Jordan, and Sicilia). The similarities with the genera from Nigeria, Ghana, and Togo are rare and totally absent with those of European margin. Accordingly, during the Middle to Late Eocene, marine connection is evident between Northern Africa and the Middle East, probable between Northern Africa and eastern Africa and totally absent between Northern Africa and European margin because ostracods similarities are absent between European and Tunisian ostracods we were identified except some cosmopolitan forms.