Paleoenvironment and source rock potential within the Jurassic-Cretaceous succession of the Nile Delta Basin, Egypt: Insights from palynology and organic geochemistry

Despite decades of active exploration in the Nile Delta, particularly in the offshore Mediterranean, the depositional settings and source rock potential of the Mesozoic strata remain unclear, primarily due to the limited number of drill cores. With its comprehensive approach, this study aims to fill gaps in our understanding of the Jurassic-Cretaceous paleoenvironments and source rock potential in one of the largest petroleum basins in Egypt and the Mediterranean region. The investigated successions are from the Abu Hammad-1 well in the onshore Nile Delta Basin, the only well that penetrated the Jurassic-Cretaceous in the basin. Our study presents an integrated palynological and organic geochemical approach, offering a comprehensive and reliable method for gaining precise insights and linking age dating to depositional environments, kerogen types, and thermal maturity. Palynological data are supplemented with organic geochemical analyses, comprising total organic carbon, Rock-Eval pyrolysis, biomarker, and elemental data. The obtained palynological results reveal two distinct assemblages, from younger to older, dated as Barremian-Aptian and Bathonian-Kimmeridgian, respectively. The studied sediments are derived from nearshore marine environments characterized by stable, oxygen-rich, suboxic bottom waters. This specific setting and proximity to the shoreline contribute to minimal preservation of organic matter. The organic content is dominated by Type III and Type IV kerogen, indicating a gas-prone source derived from terrestrial plant material and amorphous organic matter. Source rock characterization shows low thermal maturity. The study provides valuable insights into the Upper Jurassic and Lower Cretaceous geology of the Nile Delta Basin, facilitating the prediction of depositional environments and source rocks.