Sedimentary dynamics of post-rift deposits of the Gabon Interior Basin

摘要

In the terminal Barremian, the surrection of the Lambarene horst followed by a major erosional phase and by the deposition of the Aptian series of Como (or Gamba) which lie in angular unconformity on underlying deposits, make the end of the lower Cretaceous rifting in the interior basin of Gabon. After that period, the basin becomes passive and is subjected to the effects of the occidental basin whose opening leads to the formation of the southern Atlantic ocean. The rifting phase characterised by an intense tectonic activity and a fluvio-lacustrine continental sedimentation is followed by a post-rift phase characterised by a continental sedimentation (Como series of lower aptian age) evolving into an evaporite phase (Ezanga series of superior Aptian age) and a marine one (Madiela series of Albian age). That sedimentation is mainly controlled by the longitudinal faults of N140-160°E direction, linked to the rifting.