Planktonic foraminiferal biostratigraphy and paleoenvironment of the Danian/Selandian in west-central Sinai (Egypt), implications from the Nukhul section

Abstract

The foraminiferal analysis at the Danian/Selandian boundary of the Nukhul section (Egypt) enabled us to determine the biozones of Praemurica uncinata (P2); Morozovella angulata (P3a); Igorina albeari (P3b), and Acarinina soldadoensis/Globanomalina pseudomenardii (P4c). Thus, the base of Selandian is defined by the first occurrence of I. albeari and the P4c subzone covers unconformably the P3b subzone. The quantitative and qualitative analysis of the planktonic and benthic foraminifera assemblages and the isotopic analysis permitted characterization of the paleoclimate and paleoenvironment. Thus, at the middle to upper Danian, the environment was marine intertidal under a relatively cold climate. At the lower Selandian base of the Thanetian, a rise in the sea level was recorded and the warmer climatic conditions seem to be settling. In the upper Thanetian, we note the installation of colder weather conditions and a further sudden drop in sea level.

Lithostratigraphy, Stable Isotope Stratigraphy and Calcareous Nannofossils Biostratigraphy of the Danian-Thanetian at Nukhul, Sinai, Egypt

“…These events include Danian ⁄Selandian (D/S) transition (Schmitz et al, 2011), and the Mid Paleocene Biotic Event (MPBE) (Bernaola et al, 2007). These warming episodes had been characterized by drops in carbon isotope excursions (CIEs) and the level of carbonate, as well as variations in calcareous nannofossil assemblages (Dupuis et al, 2003;Aubry et al, 2007;Bernaola et al, 2007;Schmitz et al, 2011;Soliman et al, 2014;Karoui-Yaakoub et al, 2016, Kasem et al, 2017Faris et al, 2018, andAbu Shama et al, 2020). The negative δ 13 C excursions are usually interpreted as a response to increase in paleotemperature (Bornemann, 2003), possibly a carbon reservoir added more 13 C to the water and atmosphere (Dickens et al 1997).…”