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Article

Enregistrement des événements remarquables de la limite Crétacé–Tertiaire dans la coupe d’Ellès (Tunisie)

Belayouni Habib, Robin Eric, KAROUI YAAKOUB Narjess, ROCCHIA ROBERT, Zaghbib-Turki Dalila, 2000

African Journal of Environmental Science and Technology, 141-149, 331, 9, Juin 2000

Résumé

The review of the Cretaceous–Paleogene interval deposits of the Ellès section based on a detailed sampling gives a good characterization of the K/T boundary and reconstitution of the geological events underlining this boundary. Thus, the discovery of a thin Ir-rich layer, with Ni and Cr-rich spinel and shocked quartz is a well preserved record of the known cosmic event that occurred at that time. This sudden event is also corroborated by the quantitative and qualitative organic components distribution along the K/T interval. Added to some other long-term events (e.g. climatic, eustatic), it generated a mass extinction, at the K/T boundary, of specialists among the Globotruncanids and Heterohelicids planktic foraminifera species. Following this biological crisis, the biotic turnover into the Danian is slow. The underlining of all the Cretaceous–Tertiary interval biozones attests that the Ellès section is complete. If compared to the K/T stratotype and El Kef II sections, the Ellès section is found to display a better exposure of the K/T interval and shows more expanded zones and subzones. Such characteristics promote the Ellès section to be considered as a parastratotype.