The Qreiya Section at Gebel Abu Had: Lithostratigraphy, Clay Mineralogy, Geochemistry and Biostratigraphy

Calcareous nannofossil and planktonic foramininferal assemblages demonstrate that the succession at Qreiya provides a virtually complete stratigraphic reference section through the Esna Shale Formation. A detailed study of the Dababiya Quarry Beds has revealed distinct stratigraphic trends in both mineralogy and geochemistry, similar to those reported from Dababiya Quarry itself. In particular, the organic carbon isotope analysis has revealed a pronounced negative carbon isotope excursion of comparable magnitude to that recorded from Dababiya. Calcareous nannoplankton (Rhomboaster spp.-Discoaster araneus association) and planktonic foraminiferal occurrences (the so-called excursion taxa) allow unambiguous determination of this isotopic excursion as the Carbon Isotope Excursion (CIE) identified globally at the base of Eocene successions. Preliminary petrological analysis of mudstones within the Dababiya Quarry Beds has revealed a finely granular texture, possibly representing fecal pellets. This texture indicates that the sea-bed sediment may have been mobile, and subject to redistribution by gentle, wave-induced currents.