Abstract
The Cretaceous palynological and foraminiferal assemblages from northern Egypt show an intimate resemblance to their respective counterparts from northeastern Libya. The Lower Cretaceous to Cenomanian deposits in northern Egypt and Libya were subdivided and dated by means of pollen, spores, and dinoflagellates. The Neocomian is distinguished palynologically from the Late Jurassic by the first occurrence of Impardecispora and Pilosiporites trichopapillosus spores. Dicheiropollis etruscus is a characteristic late Neocomian-Barremian guide pollen as in northern Gondwana. The Barremian is also characterized by the first incoming of Ephedripites pollen and primitive angiosperm pollen like Clavatipollenites, Asteropollis, Retimonocolpites, and Liliacidites. The percentage of angiosperm pollen increases during the Aptian; Afropollis, Brenneripollis, and tricolporate pollen appear. The Albian microflora is dominated by Crybelosporites pannuceous, Afropollis jardinus, Balmeisporites, and Ephedripites. Tricolporate angiosperm and elater-bearing elements are present in the middle to late Albian and become abundant in the early-middle Cenomanian. The Aptian-Albian palynomorphs indicate restricted marine conditions and high terrestrial input into the sedimentary basins. These conditions prevented the full development of planktonic foraminiferal assemblages in northern Egypt as well as in western Libya and the Sirt Basin.
The Cenomanian is often characterized by the occurrence of large agglutinated benthonic foraminifer Thomasinella, in addition to guide palynomorphs such as Afropollis, Stephanocolpites, Dichastopollenites, and Classopollis brasiliensis. The Turonian-Maastrichtian sediments show a sharp environmental shift towards open marine conditions with abundant and well-diversified planktonic foraminiferal and only subordinate dinoflagellates, pollen, and spores.
The Cretaceous sediments with their palynological and foraminiferal contents are greatly influenced by the position of the ancient shoreline of the Tethys Sea. On the basis of the palynological and foraminiferal zonation and other stratigraphical and sedimentological data available, a chronological series of maps reconstructing the Cretaceous shorelines have been prepared. The maps also provide information about the transgression-regression phases of the Cretaceous.