The Dababiya Quarry section: Lithostratigraphy, clay mineralogy, geochemistry and paleontology
The Global Standard Stratotype-section (GSSP) for the Paleocene/Eocene (P/E) boundary has been selected in the Dababiya Quarry, near Luxor, at the base of a lithostratigraphic unit where the base of the so-called Carbon Isotope Excursion (CIE) is recorded. The Dababiya Quarry offers remarkable three-dimensional exposures of the Upper Paleocene-Lower Eocene succession in the Nile Valley which comprises the Tarawan Chalk, the Esna Shale and the Thebes Limestone. The horizon that constitutes the P/E GSSP is located in the lower part of the Esna Shale Formation. This formation, remarkably thick (~130m) at Dababiya, is largely of homogenous gray shales. Its lower part includes, however, a thin lithostratigraphic unit in a typical succession of five characteristic beds that can be followed throughout Upper Egypt, and at the base of which the GSSP is defined. We formally describe this unit as the Dababiya Quarry Beds at the same time as we subdivide the Esna Shale Formation into three formal lithostratigraphic units. The Dababiya Quarry Beds constitute the lower part of Unit Esna 2. While we place emphasis on the description of the lithology, mineralogy, carbon isotope stratigraphy and paleontology of the Dababiya Beds, we provide a mineralogic and biostratigraphic framework for the whole exposure of Esna Shale at Dababiya that constitutes essentially a complete record from the base of calcareous nannofossil Zone NP9 to Zone NP11 and planktonic foraminiferal Zone P4 to P8. The carbon isotopic excursion, measured on organic matter is ~3m thick and has an amplitude of ~4‰. The planktonic foraminiferal excursion taxa are sporadic and the distinct Discoaster araneus-Rhomboaster spp. association is persistent throughout the CIE-interval.
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