Upper Paleocene-Lower Eocene biostratigraphy of Darb Gaga, Southeastern Kharga Oasis Western Desert, Egypt
MetadataShow full item record
KeywordPaleocene/Eocene Boundary; Darb Gaga; Kharga Oasis; Planktonic foraminiferal biostratigraphy; Dababiya Quarry Member
Paleontological studies on the Upper Paleocene-Lower Eocene succession at Darb Gaga, southeastern Kharga Oasis, Western Desert, Egypt document the changes associated with the Paleocene-Eocene Thermal Maximum (PETM), such as 1) a radical alteration of the relative and absolute abundance of planktonic foraminifera; 2) a massive occurrence of the excursion planktonic foraminiferal taxa; 3) a widespread deposition of calcarenite yielding atypical (extremely high) faunal abundance associated with the younger phase of warming; and 4) a concentration of coprolites associated with the middle phase of warming. We also document the Lowest Occurrence (LO) of dimorphic larger benthic and excursion foraminifera during the earlier phase of warming at Darb Gaga, as recorded in Bed 1 of the Dababiya Quarry Member. The absence of these faunas in Bed 1 at Dababiya (the GSSP for the P/E Boundary) is likely to be due to both intense deficiency in dissolved oxygen and massive carbonate dissolution. Only remains (fish remains) of faunas that can tolerate the toxicity produced by low oxygen conditions are found in the stratigraphic record of this (oldest) phase at Dababiya. The Dababiya Quarry Member (DQM) at Darb Gaga reflects the unfolding of the sedimentary and biotic changes associated with the PETM global warming at, and following, the Paleocene/Eocene boundary on the southern Tethys platform. The changes began with a rapid increase in bottom and “intermediate” water temperature. The temperature increase was accompanied by removal of oxygen during the early and middle stages of warming. This led to the absence of both subbotinids and calcareous benthic foraminifera in the early and second coprolite-bearing phases (Beds 2 and 3 of the DQM). Dissolution seems to have no role during these stages as shown by the unusual abundance and good preservation of the warm-tolerant Ac. sibaiyaensis. This species reaches its maximum abundance in Bed 2 where it exhibits a broad range of size (63-250 μm) and shape that probably reflect optimal growth under the warmest water conditions. Thus, we infer that temperature and dissolved oxygen content of the sea-water were the main factors controlling the distribution pattern(s) of the microplankton and microbenthos during the PETM.
© The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of African Earth Sciences 118 (2016): 12-23, doi:10.1016/j.jafrearsci.2016.02.016.
Suggested CitationPreprint: Ouda, Khaled, Berggren, William A., Abdel-Sabour, Ayman, "Upper Paleocene-Lower Eocene biostratigraphy of Darb Gaga, Southeastern Kharga Oasis Western Desert, Egypt", 2016-02, https://doi.org/10.1016/j.jafrearsci.2016.02.016, https://hdl.handle.net/1912/8173
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivs 3.0 United States
Showing items related by title, author, creator and subject.
Dubin, Andrea R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2015-06)Fifty-six million years ago Earth experienced rapid global warming (~6°C) that was caused by the release of large amounts of carbon into the ocean-atmosphere system. This Paleocene-Eocene Thermal Maximum (PETM) is often ...
Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale Wade, Bridget S.; Pearson, Paul N.; Berggren, William A.; Palike, Heiko (2010-09)Planktonic foraminifera are widely utilized for the biostratigraphy of Cretaceous and Cenozoic marine sediments and are a fundamental component of Cenozoic chronostratigraphy. The recent enhancements in deep sea drilling ...
Late cretaceous (Maestrichtian) calcareous nannoplankton biogeography with emphasis on events immediately preceding the cretaceous/paleocene boundary Ehrendorfer, Thomas W. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-02)The Maestrichtian biogeography of calcareous nannoplankton is investigated in order to characterize paleoenvironmental conditions in the marine photic zone during the latest Cretaceous. Different theories explaining the ...