Age Assignment, Palaeoecology and Sequence Stratigraphic Framework of the Nukhul Formation at Wadi Baba, West-Central Sinai (Egypt)

Abstract

The Nukhul Formation has been a point of controversy until now due to a lack of index fossils, varied facies modifications, and different time gaps. As a result, the calcareous nannofossils of the exposed Miocene rocks at Wadi Baba, west-central Sinai have been studied quantitatively for the first time. An important sequence of calcareous nannofossil bioevents has been recorded in the Nukhul Formation, including the FOs of Discoaster druggii, Sphenolithus dissimilis, Helicosphaera ampilaperta, and Sphenolithus disbelemnos, which correspond to the Aquitanian age of upper NN1 and NN2 zones. The Nukhul Formation contains four intervals that reflect eutrophic conditions in the nearshore habitats with substantial nutrient input from the terrigenous influx, as shown by the dominance of cool-water taxa, Coccoliths pelagicus and Reticulofenestra minuta. The lithofacies, microfacies types, abundance, dominance, and diversity of nannofossil assemblages classified the studied interval into two depositional sequences with four system tracts. These tracts refer to fluctuations in relative sea level changes in response to the eustatic sea-level curve.

The impact of Oligo-Miocene basaltic intrusions on the petroleum system in Gulf of Suez rift basin, Egypt: new insights into thermal maturity and reservoir quality

“…The rifting of the Gulf of Suez profoundly impacted Upper Oligocene and Miocene deposits in western and central Sinai, such as in the Wadi Baba, Wadi Gharandal and Nukhul-Sudr areas (Hewaidy et al, 2012;Ayyad et al, 2023). The Lower Miocene Nukhul sandstones, which produce oil in the Abu Rudeis-Sidri Field, are characterized by four systems tracts that experienced sea level changes during the rifting phase of the Gulf of Suez (Hewaidy et al, 2012;Abu Shama et al, 2023;Farouk et al, 2023). Nukhul Formation consists of sandstones, conglomerates, and marl with cross-bedded sandstones (Scott and Govean, 1985).…”