Integrated Pseudo-Gravity, SPI, and 2D Magnetic Modelling for Hydrocarbon Prospectivity in the Upper Benue Trough, Nigeria

Pseudo-gravity transformation of aeromagnetic data was applied to constrain basement architecture and sediment thickness in part of the Upper Benue Trough, northeastern Nigeria, with implications for hydrocarbon prospectivity. High-resolution aeromagnetic data were processed using Reduction to the Equator (RTE), pseudo-gravity filtering, and Source Parameter Imaging (SPI) to emphasize deep-seated structural features relevant to basin evolution. The pseudo-gravity field reveals long-wavelength anomalies ranging from approximately −0.34 to +0.22mGal, delineating a rift-segmented basement characterized by fault-bounded depressions and uplifted blocks trending NE–SW and NW–SE.SPI depth estimates derived from the pseudo-gravity field indicate basement depths varying from about 1.3 to >14km, reflecting pronounced lateral variations in crustal structure. Application of a 7 km depth cutoff isolates basin-scale features and highlights several structurally controlled depocenters with estimated sediment thicknesses of 5–7km, particularly along the Lomi–Kolmani–Gombe corridor. Two-dimensional magnetic models further confirm the presence of rift-related basement depressions reaching depths of 4.5–5. km, flanked by shallower basement highs, and show that basement relief dominates the long-wavelength magnetic response. These depocenters coincide with negative pseudo-gravity anomalies and are interpreted as long-lived subsidence zones favorable for hydrocarbon generation and preservation. Shallower depths (