La formation d'Adakplamé (Bénin, Ouest-Afrique) n'appartient pas au Continental Terminal

Abstract The Adakplame formation includes the lower and middle parts of the northeastern plateaus of the coastal basin of Benin (West Africa) which are assigned to the “Continental Terminal” (Slansky, 1962). This formation is mainly of marine origin,, about 100 m thick, and comprises three sandy levels separated by two clayey horizons. All of them have undergone an intense ferralitcc weathering which leads to rubefaction, kaolinization and ironpan forming. The Adakplame formation ( nov. form. ) is Maastrichtian or older as it is uncomfortable on the Precambrian basement and gullied by the Maastrichtian Ketou formation. In Nigeria, the probable equivalents of the Adakplame and Ketou formations arem respectively, assigned to Cenomanian-Turonian and Maastrichtian or Campanian-Maastrichtian on paleontological basis. This result leads to an important modification in the mapping of the northern fringe of the Benin-Togo coastal basin in which the sandy plateaus are Campano-Maastrichtian to Cenomano-Turonian and do not belong to the “Continental Terminal”. This is in agreement with the results obtained in southwestern Nigeria.