Palynology of the Cretaceous-Tertiary transition in an Atlantic bore-core, off Senegal Coast, West Africa

Abstract

Palynological investigations on the Cretaceous-Tertiary transition in the bore-hole no. CM 5 drilled in the Atlantic Ocean, off Senegal Coast, West Africa have been carried out. According to the stratigraphic data the top of the Maestrichtian is marked approximately at 952 m. The present study is aimed to detail out palynological data and correlate with stratigraphic information. Samples of the sediments between 1002-944 m levels have been investigated in detail. It is observed that palynological assemblage recovered from sediments at 1002-958 m show an almost uniform distribution of taxa. Significant Maestrichtian marker taxa namely Diporoconia iszkazentgyoergyi, Ariadnaesporites ariadnae, Gabonisporites vigourouxii, Periretisyncolpites magnosagenatus, Tercissus grandis, Longapertites marginatus etc., are recorded. These marker taxa disappear at 958 m level and an abundance of pteridophytic spores is noticed. Thus a major change in floral composition is recorded at this level marking K/T transition, which is characterised by the disappearance of Maestrichtian marker taxa and presence of a fern-spike. Such major floral change is attributed to possible influence of K/T events.