Abstract:
The Late Cretaceous – Early Tertiary succession penetrated by Mbeji-1 well in the Central Chad Basin, North East Nigeria was investigated for its palynological content. This analysis was carried out in order to deduce the paleoecological and paleoenviromental condition during the deposition of the strata penetrated by the well with a view to throwing more light on the geology of the Bornu Basin. Eight nine (89) slides prepared from ditch cutting retrieved at an interval of 5 m- 25 m within a section of Mbeji -1 well was used for the study. The slides were prepared following the standard method of preparing palynological slides. Based on the stratigraphic distribution of the recovered palynomorphs, the oldest zone recognized is defined by the top occurrence of land derived Droseridites senonicus at 1935 m, while the base is tentatively placed at 3710 m (P100 Zone – Odontochitina operculata Assemblage Zone),which is the total depth of the well. Section 1785 – 1935 m of the well is dated Campanian– Maastrichtian based on the top occurrence of Dinogymnium euclaense and top occurrence of Droseridites senonicus at 1935 m. P200 Zone occurs within interval565m – 1785 m dated Early Paleocene. The sequences of the upper Cretaceous were deposited within open to shallow marine environment. This section was stratigraphically classified as the Gongila and Fika Formations. The continental environment experienced at about depth 1785 m marks the onset of Paleocene and deposition of the Gombe Formation. The Kerri-Kerri Formation was deposited in a shallow marine environment. The Chad Formation Section (depth 565 to the surface) was not studied. The age at the total depth of the well suggests that the well did not penetrate the Bima Formation.
