ABSTRACT--Land-derived pollen and spores and marine dinoflagellate cysts were extracted from
the Jurassic and Cretaceous sediments of the West Tiba-1 borehole, northern Western Desert,
Egypt. On the basis of the recovered palynomorphs, of known stratigraphical significance, the
following stages were assessed: Bathonian-Oxfordian (Middle-Late Jurassic) and Hauterivian,
Aptian-Early Albian, Late Albian-Early Cenomanian, Early Cenomanian and Late Cenomanian (Early-
Middle Cretaceous). No palynomorphs diagnostic for the Berriasian, Valanginian and Barremian
stages (Early Cretaceous) were depicted. Based on the nature and composition of the identified
palynomorph content, five informal palynomorph assemblage zones were recognised. These are:
the Gonyaulacystajurassica-Korystocysta kettonensis Assemblage Zone (PI, Bathonian-Oxfordian'),
Ephedripites-Aequitriradites verrucosus Assemblage Zone (PII, Hauterivian), Afropollis jardinus-
Duplexisporites generalis-Tricolpites Assemblage Zone (PIll, Aptian-Early Albian), Nyssapollenites-
Elaterosporites Assemblage Zone (PLY, Late Albian-Early Cenomanian) and Assemblage Zone PV
(Early-Late Cenomanian). The latter zone was differentiated into two subzones, namely the
Classopollis brasiliensis-Elaterosporites klaszii Assemblage Subzone (PVa, Early Cenomanian) and
Afropollis kahramanensis-Triporates Assemblage Subzone (PVb, Late Cenomanian). The time
stratigraphy of the studied interval was revised. The occurrences and types of the dinoflagellate
cysts, extracted from the studied succession, reflect a general shallow (shelf) marine pal~eoenvironment.