Palynological and Paleoenvironmental Characterization of the Campano-Maastrichtian Age Deposits of Adiake in the South-East of the Ivory Coast

192 samples of drill cuttings from two wells MARRY 1 and MARRY 2 respectively 99m and 95m located in the onshore basin of south-eastern Ivory Coast 94km from Abidjan have been subject of palynological analyzes to determine the environments of deposition and age of the sediments. Samples were taken from clay and silty clay levels. The palynological treatment method used is the classic one involving strong acids such as 37% hydrochloric acid and 70% hydrofluoric acid. The results showed: 1) 1618 palynomorphs comprising dinoflagellate cysts in 1132 and 486 miospores. 70% dinoflagellate cysts and 30% of miospores. This study revealed two stages namely: 2) The Campanian between depths of 94m and 58m found only in the MARRY 1 well and dated by palynomorphs: Dinogymnium acuminatum, Dinogymnium cretaceum undulocostata, Dinogymnium cooksonae, Dinogymnium westralium, Unipontidinium grande and Hystrichodinium pulchrum, Foveotriletes margaritae and Ephedri pites multicostatus. 3) The upper Maastrichtian between ratings 58m and 47m for MARRY 1 and 91m and 13m for MARRY 2 characterized by the dinocysts of genre: Andalusiella mauthei, Cerodinium granulostriatum, Cerodinium leptodermum, Senegalinium bicavatum and Senegalinium microspinosum, Foveotriletes margaritae, Longapertites marginatus, Proteacidites longispinosum, Distaverrusporites simplex, Echitriporites trianguliformis, Zlivisporites blanensis, Ephedripites multicostatus, and Monocolpites marginatus. These palynological data helped to define the paleoenvironment that was deltaic at Campanian and shallow marine that is to say coastal or estuarine at the upper Maastrichtian.