The gray clays of the Eboinda region consist of sub-rounded, fine to medium and translucent grains. A few black nodules 1 to 2 cm, sub-rounded, give off a hydrogen sulfide odor. They are strongly impregnated with bitumen. this unit yielded a rich assemblage of spores and pollen to the Cretaceous/Paleogen transition (K/Pg) namely, Longapertites marginatus, Mauritiidites crassibaculatus, Proxaperites cursus, Proxapertites operculatus, Longapertites proxapertitoids, Deltoidospora minor, Cyathidites minor, Zlivisporites blanensis, Retistephanocolpites williamsi, Spinizonocolpites baculatus. Mangrove-type paleovegetation developed in Upper Maastrichtian and in Danien. From the paleoclimatic point of view, the development of pollen mainly palms belonging to the family of Aceraceae suggests tropical and humid climatic conditions, which alternate with a warm and dry climate (development of Ephedripites sp.,) in the Upper Maastrichtian. The presence of some species of the Cytheaceae and Arecaceae family would indicate a tropical and humid climate in Danien. But the complete disappearance of the Proteaceae and Ephedraceae, indicates a cold climate at the Cretaceous-Paleogene limit.