Basement Depth Re-Estimation and Structural Trend Analysis of Sokoto Basin Northwestern Nigeria Using SPI and Analytic Signal Methods of Aeromagnetic Data

Abstract

Aim of the Study: The study's objectives were to establish the depth of the magnetic basement, identify the linear characteristics connected to the basin, and extrapolate the impact of the structure on the region's overall tectonic history.

Methodology: The basin spans latitude 11^o00^I to 13^o30^IN and longitude 4^o30^I to 6^o30^IE. It is situated at the eastern part of Iullemeden basin. Results of the study revealed total magnetic intensity (TMI) range of -1503.47nT to 1224.93nT with average of -139.27nT. Residual magnetic field anomaly result showed a range between 770.25nT to 1385 95nT. Tilt derivative result showed a range of values between -1.57054nT/km to 1.57054nT/km.

Findings: Magnetic lineament map showed major lineament in direction NE-SW and NW-SE. The lineament map also revealed cross conjugate faults. Lineament density map revealed spatial distribution and rose diagram of the lineament confirmed that the dominant trend is in the direction of Northeast- Southwest. The result of Analytic signal showed an average depth of 3.4930nT per kilometer and a thickness value of 6.986nT per kilometer. SPI result revealed an average depth and thickness as 3.1km and 6.2km respectively. Analytical signal and SPI technique results showed that the study area's north, northeastern, and northwestern regions have mineral potentials whereas the study area's south and southeast had hydrocarbon potential.

Conclusion: Despite the sedimentary thickness, the basin may not produce hydrocarbon due to the structural deformation of the basin which reflected as cross conjugate faults dominated in the potential study area. These areas with hydrocarbon potential is suggested for further geological study such as seal-fault-analysis to ascertain the sealing of the fault for hydrocarbon accumulation.