Gravity characteristics of the northern part of the Dahomeyides: continental aggregation-collision orogen and gravity smoothing in the Pan-African (600 ± 100 Ma)

The surveyed area straddles the s.s. West-African and The Nigeria-Beninian plates (Fig. 1). It corresponds to the northern part of the Volta Basin, the external and internal structural units, and the suture zone of the Dahomeyide Pan-African Orogen. The main gravity anomalies are sometimes correlated with geological outcropping formations. Numerous gravity gradient changes and discontinuities are noticed. They testify to the structural and geological complexity of this region. This complexity suggests two main hypothese: that of aggregation of micro-continents during the Pan-African; and that of a “gravity smoothing” following the great tangential movements.