Integrated Aeromagnetic Estimation of Sedimentary Thickness and Hydrocarbon Prospectivity, in Southern Bida Basin, Nigeria

Abstract

This study offers a detailed quantitative analysis of high-resolution aeromagnetic data to assess sedimentary thickness and hydrocarbon potential in the southern Bida Basin, north-central Nigeria. The investigation used sheet 183 aeromagnetic data covering 3, 025 km ² between latitudes 9 ° 0' 0 '' N- 9 ° 30' 0 '' N and longitudes 5 ° 30' 0 '' E- 6 ° 0' 0 '' E, including the Egbako region. Three complementary geophysical techniques were employed: Source Parameter Imaging (SPI), Spectral analysis, and Standard Euler Deconvolution for basement depth estimation. Regional residual separation was achieved through first-order polynomial fitting. The integrated approach produced consistent sedimentary thickness estimates, with SPI indicating depths of 0. 0545-3. 99 km, spectral analysis showing 1. 22-3. 77 km, and Euler Deconvolution estimating -0. 00405-3. 81 km. The correlation coefficient between methods exceeded 0.85, with a standard deviation of 0.89 km, demonstrating notable consistency and increasing confidence in the depth assessments. Results show widespread distribution of thick sedimentary sequences across the study area, with maximum thicknesses of 3.99 km (SPI), 3.77 km (spectral analysis), and 3.81 km (Euler Deconvolution), representing 73. 2% agreement in maximum depth estimates. These significant sediment accumulations exceed the critical threshold depths (> 2.5 km) required for hydrocarbon generation by 51-60 %. The thick sedimentary packages cover approximately 85% of the study area, with 67% displaying a thickness > 2.0 km and 34% showing a thickness > 3.0 km. The depth ranges align with optimal hydrocarbon generation windows (2.2.5-4.0 km), where source rocks undergo thermal transformation at temperatures between 60-120 ° C. Collectively, these findings highlight substantial hydrocarbon potential in the Egbako region, with quantitative metrics indicating that 78 % of the study area is prospective for hydrocarbon exploration. The research recommends advancing exploration efforts through seismic reflection and refraction studies to further define subsurface structures, identify potential hydrocarbon traps, and validate reservoir characteristics.