Enhancement and modelling of aeromagnetic data of some inland basins, southeastern Nigeria

Abstract

High resolution aeromagnetic data that can be applied in hydrocarbon search, mineral and ores explorations, archaeological investigations, UXO and metal objects detections etc. were employed in this study. The data were used to map the spatial distribution of short and long wavelength magnetic anomalies and thicknesses of sediments in some parts of southeastern Nigeria. Standard data enhancement techniques such as first vertical, second vertical and horizontal derivatives, upward and downward continuations, and depth determination techniques like source parameter imaging (SPI) and modelling using 2D GM-SYS in Oasis Montaj were performed. Results show long wavelength anomalies within the Calabar Flank while Ikom-Mamfe Embayment was dominated by short wavelength anomalies. Depth estimate from SPI revealed a maximum depth of about 6127 m within the Calabar Flank. Additionally, two dimensional (2D) modelling technique show thickness of the range, >7000 to 5000 m of sediments in the Calabar Flank and Ikom-Mamfe Embayment respectively. The results of the SPI and 2D modelling techniques correlated relatively well in the Calabar Flank. The maps generated after performing the enhancement, validated the surficial regional geology of the study area with defined boundaries between the Cretaceous sediments and the Precambrian basement rocks.