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

Karoui-Yaakoub, N. ; Grira, C. ; Mtimet, M. S. ; Negra, M. H. ; Molina, E. (Universidad de Zaragoza)

Resumen: The biostratigraphic analysis of the Eocene-Oligocene transition of the Menzel Bou Zelfa and Jhaff sections in northeastern Tunisia (Cap Bon peninsula) allows us to identify a continuous planktic foraminiferal biozonation. The following biozones were recognized: Globigerinatheka semiinvoluta Zone (E14), Globigerinatheka index Zone (E15), (Hantkenina alabamensis Zone (E16) of the upper Eocene and Pseudohastigerina naguewichiensis Zone (O1) of the lower Oligocene. A rapid mass extinction event in planktic foraminifera occurred at the Eocene-Oligocene transition, including the extinction of the turborotalids (Turborotalia cerroazulensis, Turborotalia cocoaensis and Turborotalia cunialensis) followed by a significant size reduction of the genus Pseudohastigerina and the extinction of the hantkeninids (Hantkenina alabamensis, Hantkenina brevispina, Hantkenina nanggulanensis and Cribrohantkenina lazzarii), which mark the Eocene/Oligocene boundary. These species were tropical and subtropical surface and intermediate dwellers, with distinctive morphologies (carinate turborotalids and spinose hantkeninids), which were well adapted species of k-strategy. The surviving planktic foraminifera species were quite similar in morphology with globular chambers (globigerinids) and small planispiral (pseudohastigerinids), which were opportunistic species of r-strategy. The recognition of a 4 m thick interval, between the extinction of turborotalids and hantkeninids, indicates that the section is continuous and one of the most expanded throughout the Eocene-Oligocene transition. This section could serve as an auxiliary section (hypostratotype) for the complete definition of the Global Stratotype Section and Point for the Eocene/Oligocene boundary, which mark the base of the Rupelian Stage.

Idioma: Inglés

DOI: 10.1016/j.jafrearsci.2016.11.009

Año: 2017

Publicado en: Journal of African Earth Sciences 125 (2017), 126-136
ISSN: 1464-343X

Factor impacto JCR: 1.532 (2017)

Categ. JCR: GEOSCIENCES, MULTIDISCIPLINARY rank: 122 / 189 = 0.646 (2017) - Q3 - T2

Factor impacto SCIMAGO: 0.681 - Geology (Q2) - Earth-Surface Processes (Q2)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E05
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/CGL2014-58794-P

Tipo y forma: Artículo (PostPrint)

Área (Departamento): Área Paleontología (Dpto. Ciencias de la Tierra)