MIGRATIONS OF LITTORAL MICROFAUNA BETWEEN TROPICAL AMERICA AND THE NWEDGE OF WEST-AFRICA IN THE EOCENE AND THE OLIGOCENE

Large Eocene and Oligocene foraminifers of the families Discocyclinida e, Helicolepidinidae, Lepidocyclinidae, widespread in tropical America n regions, have been found in wells drilled on the Atlantic margin of the north-west African Continent. Inversely, large Eocene foraminifers of the Nummulitidae family have been found in parts of the Caribbean region. These observations have led to envisage Atlantic migrations, i n opposite directions, of planktonic larvae of these microfaunas.