Litho-structural and hydrothermal alteration mapping for delineation of gold potential zones within Kaiama, northwestern Nigeria, using airborne magnetic and radiometric data

The mapping of lithology, structures, and hydrothermal alteration zones in Kaiama, northcentral Nigeria, was carried out to locate possible gold mineralization zones. Both aeromagnetic and aeroradiometric datasets were used in the investigation. Enhancement techniques such as first vertical derivative, analytic signal, Euler deconvolution, 2D power spectrum, and center for exploration targeting (grid and porphyry) as well as ratio and ternary maps were employed to aid in the interpretation process. The study reveals NE-SW, NW–SE, E-W, and N-S structural orientations dominate the area. The most important was the NE-SW, which was thought to be the best direction for mineral resources within the region. Also, depth estimation of shallow and deep-seated structures calculated using Euler deconvolution technique ranged from 250 to 1546 m, while power spectrum gave a range of 468–1853 m. Aeroradiometric analysis based on the concentrations of equivalent thorium (eTh), equivalent uranium (eU), and percentage potassium (%K), as well as radiometric ternary map, revealed the presence of nine (8) lithological units and hydrothermal alterations. Finally, a composite map was created that included geology, structures, and hydrothermally altered zones. From the map, tight concordance between known gold mineralization locations and the interpreted structural and hydrothermal complexities sheds a light on similar mapped features that may be new promising sites for gold mineralization. However, the precise detection and evaluation of possible ore-bearing zones in the area require more geological and geophysical investigation.