Delineation of Mineral Potential Zones Over Lower Part of Sokoto Basin, Northwestern Nigeria Using Aeromagnetic Data

Abstract

In an attempt to delineate mineral potential zones, Subsurface investigation was carried out over the lower part of Sokoto basin northwestern Nigeria. The area lies between latitude 10.5oN to 11.5oN and longitude 04oE to 05oE with an estimated total area of 12,100km2. Four (4) high resolution aeromagnetic data sheets were acquired from the Nigerian Geological Survey Agency (NGSA) and were processed in to total magnetic intensity (TMI) map using Oasis Montaj. The result was interpreted using qualitative approach. The composite total magnetic intensity (CTMI) map revealed heterogeneity in the magnetic signature, ranging from -64.1nT to 123.6nT. Regionalresidual separation was performed on the composite total magnetic intensity map using polynomial fitting. The residual map was subjected to first and second vertical derivatives, downward continuation, analytic signal and tilt derivative. The result of the analyses, gave rise to some directional gradient maps consistently depicting NESW trending lineaments. The result was further authenticated by comparing the first vertical derivative map with the lineament map of the study area which revealed some degree of agreement. Hence, the lineaments and veins identified could play host to mineralization in the area.