Organic Matter Assessment and Paleoenvironmental Changes of the Middle Jurassic Main Source Rocks (Khatatba Formation) in the North Western Desert, Egypt: Palynofacies and Palynomorph Perspectives

The Middle Jurassic in the north Western Desert, Egypt, was a time of complex tectonics and increased environmental perturbations attributed to predominant sedimentation organic carbon-rich fine siliciclastic carbonate deposits Khatatba Formation. Although some studies have addressed hydrocarbon potential source rock characteristics Formation, regional-scale investigation prevalent paleoenvironmental conditions matter is still necessary. In this study, Formation investigated for detailed palynofacies analysis palynomorph composition assess kerogen types reconstruct depositional patterns on regional scale. For purpose, 116 drill cuttings were collected from five wells Matruh, Shushan, Dahab-Mireir Basins. Moderately diverse assemblages spores, pollen, dinoflagellate cysts are reported. Age-diagnostic cysts, including Adnatosphaeridium caulleryi, Dichadogonyaulax sellwoodii, Korystocysta gochtii, Wanaea acollaris, Pareodinia ceratophora, along with occasional records Systematophora areolate penicillate, defined Bajocian–Callovian age. Based particulate (POM) composition, four (PFAs) identified. PFA-1 most common within studied wells. It contains high proportions phytoclast fragments versus low contents amorphous (AOM) palynomorphs by gas-prone Type III. PFA-2 comprised moderate abundances AOM oil-prone II. PFA-3 dominated phytoclasts III, whereas PFA-4 consists defining indicates deposition proximal active fluvio-deltaic sources marginal marine enhanced contributions terrestrial/riverine influx. reveal under an dysoxic anoxic inner neritic shelf due abundant occurrences spores coastal shallow cysts. suggests suboxic distal because proximate chorate Thus, experienced predominantly water column part southern margin Tethyan Ocean where Basins located.