Determination of Sedimentary Thickness of Parts of Middle Benue Trough, Northeast Nigeria, Using High-Resolution Aeromagnetic Data

Abstract

The sedimentary thickness covering parts of middle Benue Trough, Northeast Nigeria, was determined with the purpose of assessing its hydrocarbon potentials. Longitude 9° E covers the area—10° E, and Latitude 8° N—9.50° N, and with total area coverage of 18,150 km2. Polynomial fitting method of order one was used to obtain its regional–residual separation. The residual data obtained were analysed using the analytic signal, source parameter imaging (SPI) and spectral depth analytical techniques. Results from the analytic signal technique showed that the area is made up of high and low magnetic anomaly amplitude. The high amplitude anomaly dominates the northern region while the southern region is dominated with low amplitude anomalies. Similarly, results from the SPI revealed a sedimentary thickness ranging between 101.8 and 2550.0 m while that of the spectral analytical method showed that the sedimentary thickness of the study area ranges between 1.20 and 3.20 km. The highest sedimentary thickness from both methods agreed in terms of space. This sedimentary covered could be found around the central and southern parts of the study area, which also agreed with the areas with low amplitude anomalies of the analytical signal results. The estimated depths from the spectral analytical method were contoured to portray the basement isobaths for the study area. The sedimentary thickness of about 3 km might be sufficient for hydrocarbon maturation in the area.