Estimation of sedimentary thickness using spectral depth analysis approach: A case study of Sokoto Basin of northwestern Nigeria

Abstract

Spectral depth analysis using high resolution aeromagnetic data was carried out to evaluate the sedimentary thickness of northeastern part of Sokoto Basin, Nigeria. The study area is situated between longitude 50 00׳00״E to 6000׳00״E and latitude12030׳00״N to 13030׳N. Covering four (4) sheets namely; sheet 11 (Rabah), sheet 12 (Isah), sheet 30 (Dange) and sheet 31 (Mafara). Spectral depth analysis and source parameter imaging (SPI) were carried out on the composite map of the area to estimate depth variation to basement and infer areas of probable hydrocarbon maturation prospects. The result of the spectral studies indicates an increase in sedimentation northeastern part, with several depressions on the basement rock. Two prominent magnetic layers of depths, deeper depth (Z1) and shallow depth (Z2) varying from 0.91 to 2.09 km and 0.35 to 0.73 km were observed with averages 1.6025 and 0.549 km respectively. Source Parameter Imaging (SPI) depth result ranges from 0.239 km (shallow magnetic bodies) to 1.912 km (deep lying magnetic bodies). These blocks where higher sedimentary thicknesses are observed in the study area such as blocks G (2.02 km), K (2.20 km) L (2.09 km) and P (1.91 km) are probable sites for prospect of hydrocarbon maturation in the study area.