Integrated Interpretation of Aeromagnetic and Aero-radiometric Data to Delineate Structures and Hydrothermal Alteration Zones Associated with Gold Mineralization in Parts of North-Central Nigeria

Abstract

Locating zones of possible gold mineralization potentials in parts of north-central Nigeria has been performed in this work by mapping lithology, structures, and hydrothermal alteration regions from aeromagnetic and aeroradiometric data. Some enhancement techniques such as first vertical derivative tilt derivative, analytic signal, and center for exploration targeting grid analysis were used for data analysis and interpretation. The CET grid analysis) reveals that the extracted lineaments are primarily oriented in the NE-SW, NNE-SWW and E-W directions. Two to three distinct magnetic zones; the very high, the moderate, and the low magnetic zonesare seen on the analytical signal map. While the high magnetic anomalies correlate with sandstone, siltstone, and shale, the zones of high magnetic anomalies in the northern half are associated to migmatite, gneisses, and biotite. The Euler deconvolution analysis indicates a broad range of depths for the magnetic sources in the region. The sources that are deeper than 2000 meters, between 1000 and 2000 meters, between 500 and 1000 meters, and shallower than 500 meters are specifically indicated by the depth estimates. Furthermore, potential mineralization zones were identified by demarcating areas with hydrothermal alteration zones that align with lineaments obtained from the first vertical derivative map of the studied region. The ternary image showed that coarse porphyritic biotite hornblende granite was primarily linked to the hydrothermally altered zones or mineralized environments in the research area.