Integrated Gravity and Magnetic Derivative Modelling for Structural Control of Gold Mineralization in North-Central Nigeria
Lawrence Jane Osita
*
Department of Geophysics, Federal University of Technology Minna, Niger State, Nigeria.
Abu Mallam
Department of Physics, University of Abuja, Abuja, Nigeria.
Nasir Naeem Abdulsalam
Department of Physics, University of Abuja, Abuja, Nigeria.
Gajere Jiriko Nzeghi
Department of Geology and Mining, University of Abuja, Abuja, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Structural controls play a critical role in the localization of gold mineralization within Precambrian basement terrains. For this study, integrated gravity and magnetic derivative modelling is utilized to assess structural controls on gold mineralization in North-Central Nigeria. Schist belts, granitoid intrusions, and fault systems are the drivers behind mineral deposition in this region that makes up part of the Nigerian Basement Complex. In order to highlight subtle structural signatures in the aeromagnetic and bouguer gravity data, the datasets were processed using multiple derivative filters including the first vertical derivative (FVD), tilt derivative (TD), and analytic signal (AS). Structural lineaments were identified and analysed to describe possible pathways for the movement of hydrothermal fluids. Integration of gravity and magnetic derivatives identifies at least 48 major lineaments, with dominant NE–SW orientations (45%) and secondary NW–SE trends (33%) that correspond to the main tectonic fabrics of the basement. Strong spatial correlations were observed between identified structural lineaments and documented gold occurrences. A key finding from this study is that 72% of documented gold occurrences are located within 2 km of major lineaments, with the highest density of occurrences along fault intersections and zones of structural complexity.
Keywords: Gravity, magnetic derivatives, structural control, North-Central Nigeria, gold exploration