A Geodynamic Model for Cretaceous Rifting and Inversion in the Nigerian Sedimentary Basins: Implications for Continental Reconstruction

The Cretaceous sedimentary basins of Nigeria, including the Anambra, Chad, Dahomey, and Benue Trough systems, developed contemporaneously during South Atlantic rifting but differ markedly in their structural styles and inversion histories, offering a natural laboratory for testing competing models of failed rift and transform margin dynamics in equatorial Africa. This study constructs a quantitative geodynamic model for Cretaceous rifting and inversion in Nigerian sedimentary basins through synthesis of new geophysical data, published geochronology, and continent-scale plate kinematic reconstructions. Gravity and magnetic data compilations are used to model crustal thickness variations beneath each basin and constrain the geometry of rift-related normal faults at depth. Two-dimensional lithospheric flexure modelling is applied to evaluate the subsidence history at twelve basin depocentres, distinguishing tectonic subsidence from sediment and water loading components. Comparison of modelled and observed subsidence anomalies tests the applicability of uniform stretching, depth-dependent stretching, and decompression melting models to individual basins. Plate kinematic restoration of the African plate is performed using GPlates software to place basin formation in the context of evolving opening vectors between Africa and South America. An original conceptual model is proposed in which differential reactivation of pre-existing Precambrian suture zones controlled the variability in rift axis orientation and inversion intensity across Nigerian basins. This model is tested against independent constraints from seismic reflection profiles and isotopic data. Keywords: geodynamics, Cretaceous rifting, Nigerian basins, plate kinematics, lithospheric stretching.