Mesozoic palynology and continental sediments in NE Africa (Egypt and Sudan) - a review

Abstract

In Egypt and Sudan most palynogical data are derived from predominantly clastic sequences in research wells for oil, water and other sedimentary deposits. The partly coal-bearing Middle Jurassic is characterized by dominance of pteridophytes while increasing percentages of gymnosperms may be noted in the Late Jurassic. The Jurassic-Cretaceous boundary is difficult to define, but Ischyosporites-Cicatricosisporites assemblages have been interpreted as Late Jurassic and overlying assemblages with Impardecispora, Geicheniidites, Classopollis etc. as Neocomian. The appearance of rare early angiosperms and their subsequent rise is documented e.g. in the Six Hills (Barremian) and in the shallow marine Abu Ballas Formation (Aptian). More advanced angiosperm types (tricolpates, tricolporates, triporates) occur in the post-Aptian. Elater-bearing spores ( Elaterosporites) associated with Afropollis form a distinctive element of the Albian (to Early Cenomanian) palynofloras known from Northern Egypt and recently discovered in Northern Sudan. In the Coniacian-Santonian, the spinose tetrads of Droseridites senonicus and large tricolpate pollen of the Foveotricolpites giganteus group become the most characteristic members of the terrestrial palynofloras. Distinctly marine palynomorphs reach the middle latitudes of Egypt for the first time with the Campanian-Maastrichtian transgression. Reduced salinity in the Phosphate Formation is reflected by peridinoid (e.g. Andalusiella, Senegalinium) communities interfingering with pollen and spores dominated associations. More open marine conditions in the overlying Dakhla Shale are documented by the rise of cosmopolitan gonyaulacoids such as Spiniferites, Glaphyrocysta and Florentinia.