Abstract. Diverse and well preserved palynofloras were recognized in the Lower Cretaceous succession penetrated by well Siqeifa 1-X in northern Egypt. Dinoflagellate cysts such as Subtilisphaera senegalensis
was regarded, with the spores Impardecispora apiverrucata and Aequitriradites spinulosus, as important Berriasian to Barremian species.
Afropollis operculatus/zonatus pollen and spores such as Balmeisporites holodictyus, Trilobosporites laevigatus and Duplexisporites generalis are diagnostic of Aptian. The lowest occurrences of the pollen
Afropollis jardinus, the spore Crybelosporites pannuceus and elaterates such as Elaterosporites klaszii, Elaterocolpites castelainii and Elateroplicites
africaensis characterize the Albian/lower Cenomanian interval. The palynofloras enabled the recognition of five spore-pollen and four dinoflagellate zones, which are correlated with regional records, mainly from Egypt and Libya. The vertical distribution of terrestrial and marine palynomorphs, along with palynodebris, reflects two regressive marginal marine cycles during Berriasian-Barremian and Albian-lower Cenomanian times whereas the Aptian witnessed a transgressive open marine (inner shelf) environment. A warm humid palaeoclimate was
inferred during deposition of the investigated succession of the borehole, in contrast to the known warm arid to semi-arid climate, suggested for the Northern Gondwana Realm during Early Cretaceous
times. This is probably due to the palaeogeographic position of Egypt during Early Cretaceous times or, to a local reason. Palynofloras from Siqeifa 1-X borehole, with Afropollis pollen and elaterates, are of North
African aspect and share the broad characteristics of the ‘‘Albian-Cenomanian Elaterates Province’’ of Herngreen et al. (1996). Abundance of spores and araucariacean pollen are transitional features between those in North Gondwana and Southern Laurasia but, unlikely, typical transitional assemblages lack bisaccates conifers and have Gleicheniaceae
spores.

In this work, we study the flow and heat transfer characteristics of a viscous nanofluid over a nonlinearly stretching
sheet in the presence of thermal radiation, included in the energy equation, and variable wall temperature. A
similarity transformation was used to transform the governing partial differential equations to a system of nonlinear
ordinary differential equations. An efficient numerical shooting technique with a fourth-order Runge-Kutta scheme
was used to obtain the solution of the boundary value problem. The variations of dimensionless surface
temperature, as well as flow and heat-transfer characteristics with the governing dimensionless parameters of the
problem, which include the nanoparticle volume fraction j, the nonlinearly stretching sheet parameter n, the
thermal radiation parameter NR, and the viscous dissipation parameter Ec, were graphed and tabulated. Excellent
validation of the present numerical results has been achieved with the earlier nonlinearly stretching sheet problem
of Cortell for local Nusselt number without taking the effect of nanoparticles.