Foraminiferal biostratigraphy and paleoenvironments of the Danian-Selandian succession at the Kharga Oasis, Western Dese
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S. I. GEOLOGY OF AFRICA
Foraminiferal biostratigraphy and paleoenvironments of the Danian-Selandian succession at the Kharga Oasis, Western Desert, Egypt Abdel Galil A. Hewaidy 1 & Sherif Farouk 2 & Youssef S. Bazeen 1 Received: 12 September 2018 / Accepted: 11 January 2019 # Saudi Society for Geosciences 2019
Abstract The present work deals with the foraminiferal investigations and analyses of the Danian-Selandian (D-S) succession at Naqb El-Rufuf and Umm El-Ghanayim sections in the Kharga Oasis. Five planktonic foraminiferal zones and subzones (P1c, P2, P3a, P3b, and P4a) were recognized within the studied sections. The D/S stage boundary is characterized by a faunal break at the P3/P4 zonal boundary owing to completely or partially absence of the P3b subzone. This hiatus reveals the dual signature of both the eustatic sea-level changes and the regional tectonic event of the Syrian Arc System. The studied interval is subdivided into three transgressive-regressive sequences bounded by three sequence boundaries at the Cretaceous-Paleogene (K/Pg.) boundary, the boundary between P3a/P3b subzones and the D/S boundary, respectively. The D/S transition is associated with substantial changes in the structure and composition of the foraminiferal assemblages point to extensive paleoenvironmental turnover. The latest Danian sediments were deposited under deep inner-shallow middle neritic environments with oxygen-depleted bottom water conditions and increased trophic level, where an outer neritic environment with meso-oligotrophic and well-oxygenated bottom water conditions prevailed during the deposition of the Selandian deposits. Keywords Danian-Selandian . Foraminiferal biostratigraphy . Paleoenvironments . Latest Danian Event (LDE) . Kharga Oasis
Introduction The Early Paleogene is a dynamic portion of the geological record, characterized by a long-term global warming trend (Zachos et al. 2001; Westerhold et al. 2011). It is interrupted by short extreme warming pulses called hyperthemal. Of
This article is part of the Topical Collection on New Advances and Research results on the Geology of Africa * Youssef S. Bazeen [email protected] Abdel Galil A. Hewaidy [email protected] Sherif Farouk [email protected] 1
Geology Department, Faculty of Science, Al-Azhar University, PO. Box: 11884, Cairo, Egypt
2
Exploration Department, Egyptian Petroleum Research Institute, Nasr City, Egypt
these, the Latest Danian Event (LDE) that precedes the Danian/Selandian (D/S) boundary and the Mid-Paleocene Biotic Event (MPBE) that precedes the Selandian/Thanetian (S/Th) boundary and the Paleocene-Eocene Thermal Maximum (PETM) at the Paleocene/Eocene (P/E) boundary (Bralower 2002; Speijer 2003a; Zachos et al. 2003; Petrizzo 2005; Bernaola et al. 2007; Bornemann et al. 2009; Obaidalla et al. 2009; Westerhold et al. 2011; Sprong et al. 2013). These events are accompanied by great faunal turnovers in many groups of the micro-organisms, attributable to substantial paleoenvironmental changes (e.g., Thomas 1990; Speijer 1994; Sp
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