Manual of Neogene foraminifera from off-shore Nile Delta (Egypt) and their biostratigraphic significance

Abstract

The Mediterranean Nile Delta is a major target for hydrocarbon reservoirs. In the search for hydrocarbons, high-resolution biostratigraphy has long been established as high-impact and low-cost solution to face the challenges in the move towards structurally more complex and unexplored areas. To date, the biozonation of the Nile Delta is largely provided by benthic and planktonic index foraminifera. We have examined the foraminifera assemblages from NDOB-1, a borehole in the northern part of the Nile Delta. The material recovered provides unique and exceptionally well-preserved microfossil biotas that completely cover the Neogene succession (Middle Miocene to Pleistocene). This allows the establishment of an intact biozonation scheme for the Nile Delta region with reliable chronostratigraphic correlation and suitable industrial applications.The stratigraphic succession of the Nile Delta region consists of seven formations: Sidi Salim Formation, Qawasim Formation, Rosetta Formations, Abu Madi Formation, Kafr El Sheikh Formation, El Wastani Formation and Mit Ghamr Formation. Examination of the planktonic foraminifera assemblages of the NDOB-1 borehole from the deep part of the Nile Delta lead to the identification of twelve biozones: Globorotalia inflata Interval Zone, Globorotalia aemiliana Interval Zone, Globorotalia puncticulata Interval Zone, Globorotalia puncticulata- Globorotalia margaritae Concurrent Range Zone, Globorotalia margaritae Interval Zone, Sphaeroidinellopsis seminulina Acme Zone, Non-distinctive Zone, Globorotalia suterae Interval Zone, Globigerina woodi Interval Zone, Globorotalia mayeri Interval Zone, Globorotalia fohsi peripheroronda Interval Zone and Praeorbulina glomerosa Interval Zone. The biozones fully cover the time span from the Middle Miocene to the Pleistocene. The benthic foraminifera recovered allow the identification of five benthic biozones for the Pliocene and Pleistocene: Hyalinea balthica Interval Zone, Bulimina marginata Interval Zone, Bulimina aculeata Interval Zone, Gyroidinoides laevigata Interval Zone and Uvigerina rutila Interval Zone. The identified planktonic bioevents were used to calibrate the studied Neogene section with the Astronomically Tuned Neogene Time Scale (ATNTS, 2012).