Evaluation, analysis and interpretation of aeromagnetic and satellite imagery data acquired over the Nigeria confluence and environs; Northcentral Nigeria were carried out in order to characterise the structural framework of the study area. Fourier domain of digital filtering tools and reduction to magnetic equator (RTE) operations were achieved to enhance the available data’s results. The geomagnetic field of the earth was removed from the aeromagnetic data using the IGRF- 12 model. Results from the 2D radially average power spectrum of the enhanced magnetic data estimate the depth of the magnetic sources as 20m. Several digital image enhancement techniques such as edge enhancement and general contrast stretching were applied to the satellite imagery after which the lineaments extracted from the magnetic data and images were mapped out on-screen using ArcMap 10.8. The RTE map showed a high magnetic intensity values ranging from 33051. 93 nT to 33165.3 nT and trend approximately E -W direction at the eastern and northwestern parts. The digital elevation model (DEM) of the confluence and environs was used to enhance geomorphic features. The structural lineaments orientation obtained from the analysis showed that the primary structural lineaments bearing is NE – SW, ENE -WSW and NNW – SSE and the structural directions derived from the 2D maps are aligned along NE – SW and NW – SE. This conforms to the general trend of structures produced by the Pan African events.

This study aimed to delineate the intrusion body that controls the structural setting and formation around the river Niger-Benue confluence zone with particular attention to its solid mineral potentials, this is achieved in mapping subsurface structural features through the analysis of recent high-resolution aeromagnetic (HRAM) data-sets with the purpose of examining their effects on geological structures that characterize the confluence zones from the study area. To obtain the necessary reduction in geomagnetic variation, measurements of regional gradients and time variation were used. After applying the reduction to the magnetic equator (RTE) to the corrected magnetic data that was obtained from the Nigerian Geological Survey Agency, NGSA, it was possible to determine the regional expansions of subsurface structural units for both qualitative and quantitative interpretations. In addition, the edge detection method is used to depict the structures and buried subsurface anomalies. Different handling processes were applied to the (HRAM) data, such as local wavenumber (SPI), power spectrum analysis, and Euler and Werner deconvolution analysis. The RTE magnetic anomaly caused by local structures and anomalous body delineated six sub-basins with low amplitude response, which agrees with the total gradient anomaly (analytic signal) and tilt of angle derivative that clearly outlined and characterize edges of lithostratigraphic of Niger-Benue river confluence zones. The sub-basin delineated are the southern Bida basin and northern Anambra basin. The source parameter imagings as well as the Euler and Werner deconvolution were used to delineate major subsurface structures and determine their source depth. Results showed that the area was affected by different lineament trending NE-SW, E-W, and S-E trends. Directional analysis indicates that the dominant trend agrees with the regional fault orientations. The estimated depth to the top of the lineaments on average varies from 0.3 km to 4.6 km and it is relatively deeper in the basins compared to the surrounding areas giving clues to the amount of sediment infill. A 2D forward model showed a sedimentary thickness ranging from 1 to 7 km, and this estimated depth is consistent with the average of 3.5 km proposed by previous researchers.