Palynostratigraphy and paleoenvironmental reconstitution of the Paleocene-Eocene N’kapa Formation: Ngata and Moulongo series (Douala sub-basin, Cameroon)

Abstract

A total of 72 samples from two wells (Ngata and Moulong) intersecting the N’kapa Formation of the Douala sub-basin were subjected to palynological analysis and yielded a rich assemblage of mainly terrestrial palynomorphs including Palmae pollens and dinocysts. Statistical analyses of the fossil counts led to the correlation of the two wells, outlining two informal palynozones: NpI inferred to be upper Paleocene in age with the first appearance datum of several late Paleocene pollen species such as Crototricolpites protoannemariae, Clavatricolporites leticiae, Clavatricolpites densiclavatus, Racemonocolpites racematus, Retitricolpites cf. simplex, Spathiphyllum vanegensis, and Ulmoideipites krempii. The early Eocene is inferred by the first occurrence of Retibrevitricolpites triangulates, characterizing NpII palynozone. Based on the presence and dominance of Palmae (Psilamonocolpites, Mauritiidites and Spinizonocolpites), Pteridophytes (Laevigatosporites) and Proteaceae (Echitriporites trianguliformis), a coastal swamp environment associated with a warm and humid climate is suggested.