Mapping lithological units, structural lineaments and alteration zones in the Southern Kibi-Winneba belt of Ghana using integrated geophysical and remote sensing datasets

Abstract

Geophysical and remote sensing datasets were employed to delineate potential zones of gold mineralization within the southern Kibi-Winneba belt of Ghana. The study area, which is characterized by the Birimian metavolcanic and metasedimentary rocks with prevalence of intrusive granitoids hosts several scientifically unguided operational activities by artisanal miners locally referred to as Galamsey. In this study, various enhancement techniques were employed on geophysical datasets encompassing magnetic, gravity and radiometric to delineate various lithological units, which corroborated with the Birimian formation and its related granitoid intrusives within the study area. The Center for Exploration Targeting grid analysis and Line Module Algorithm techniques were employed respectively on the magnetic and Sentinel 2A datasets to delineate various structural lineaments within the study area. Approximately 72% and 67% structural lineaments delineated respectively from the magnetic and Sentinel 2A datasets trended in the NE-SW and N-S direction, which control gold mineralization within the Birimian system. The prinicpal component analysis based on the Crosta technique was employed on the Sentinel 2A bands to highlight alteration zones within the study area. A potential map of gold mineralization zones within the study area was generated by integrating exploration layers comprising magnetic, gravity, structural density, radiometric and alteration zones delineated by Crosta technique. This mineral potential map categorized the belt into low, moderately low, moderately high and highly prospective regions with area coverage of 600.4 km2, 681.27 km2, 635.95 km2 and 295.20 km2 respectively. The mineralization potential map obtained was validated with available gold geochemical data and locations of artisanal mining operations (Galamsey), which corroborated with the highly potential mineralization zones of gold deposits delineated within the study area.