Sedimentological and palynostratigraphic study of the cenomanian to turonian deposits of the beno-3x well, east of the côte d’ivoire sedimentary basin.

With a view to establishing a reliable palynostratigraphic scale of the Cenomanian and the Turonian in the eastern margin of the Ivory Coast basin, around 20 drill cuttings samples from the BENO-3X well were studied. The lithological study of these excavations revealed an alternation of gray marl with whitish laminations, massive gray clays to subfissile, friable sandstones with calcareous cement, fine to coarse sands, a small proportion of friable and sandy limestones. These cuttings have undergone a classical palynological treatment using strong acids (37% hydrochloric acid and 70% fluoridric acid) to make thin sections. The blend made up of palynomorphs; Classopollis classoides, Ephedripites barghoornii, Classopollis spp, Classopollis triangulatus, Classopollis jardinei, Ephedripites barghoornii, Pemphixipollenites inequiexinus, Tricolporopollenites sp S. 152, Cretaceisporites polygonalis, Cretaceisporien sp., made it possible to highlight the Frankish Cenomanian. This study also revealed the presence of Galeacornea clavis that Jardiné and Magloire (1965) could not find in the sediments of the Ivory Coast during the years 1965. As for the Turonian reworked following the great Turonian regression, it was brought to light thanks to the palynomorphs; Droseridites senonicus, Droseridites baculatus, Tricolporopollenites sp. SCI 141, Tricolpites giganteus, Tricolpites microstriatus sp. SCI 107, Tricolporopollenites sp. SCI 428, Tricolpites sp SCI 427, Tricolpites sp SCI 348-155, Tricolpites sp. SCI 13.