Maastrichtian-early Paleocene foraminiferal palaeobathymetry and depositional sequences at Gebel El Sharawna, south Luxor, Egypt

Abstract

Maastrichtian‐early Paleocene foraminiferal palaeobathymetry, palaeodiversity and vertical facies changes of Gebel El Sharawna, south Luxor, Egypt have been studied to determine the depositional sequences, their relationships to global records and/or tectonic signatures. Five benthonic assemblages are recorded and replicated in the present study reflect fluctuation in palaeo‐water depth from restricted marginal marine to outer shelf palaeoenvironments. Four sequence boundaries that coincide with the Campanian/Maastrichtian, intra‐early Maastrichtian, Early/Late Maastrichtian, Cretaceous/Palaeogene (K/Pg) and intra‐Danian were recognized based upon sharp vertical facies changes, foraminiferal assemblage changes, hiatuses, mineral hard ground and reworking. The K/Pg unconformity reveals an unexpected ca. 4.2 Myr time gap as indicated by the absence of the CF2 Zone through lower part of the P1c Zone. It is easily distinguished in the field by conglomeration and winnowing of phosphate and glauconite in the lower Paleocene. These sequence boundaries defined five third‐order depositional sequences mainly developed as the result of the eustatic sea‐level changes, coupled with the Arabian–Nubian shield tectonic uplift at the southern edge of the Tethys Ocean.

Late Paleocene–Early Eocene foraminiferal paleobathymetry and depositional environments and their sequence stratigraphic implications of Gebel Duwi, Red Sea, Egypt

“…Through the P/E boundary event, the planktonic foraminiferal fauna displays faunal turnover and temporary diversification, visibly represented through a group rich with planktonic foraminifera of tropical which contain elements of the distinguishing planktonic foraminiferal excursion taxa, as Morozovella allisonensis, and Acarinina sibaiyaensis Ouda et al, 2012;Pardo et al, 1999;hewaidy et al, 2019a). The paleobathymetry and depositional environment depended on species composition, abundance, morphogroups and foraminiferal diversity could be providing excellent tools for reconstruction of the paleowater depth of climate changes or/and depositional sequences (Alegret and Ortiz, 2007;Alegret and Thomas, 2009;Alegret et al, 2012;Farouk and Jain, 2016;Farouk et al, 2019). Morphogroup analysis is advanced in a try to assess paleobathymetric and sediment trends (habitat of life; epifaunal, infaunal) reflected by benthic foraminiferal assemblages, and that technique was applied in many studies of both shallow and deep-water positions (Koutsoukos and hart, 1990;Tyszka and Kaminski, 1995;Ashckenazi-Polivoda et al, 2018).…”