Mapping geological structures in Central Region, Ghana using airborne magnetic and radiometric datasets: Groundwater Implications

To delineate geological signatures that influence the occurrence of groundwater in crystalline terrain of Central Region, Ghana, aeromagnetic and radiometric datasets were processed using Oasis Montaj software to delineate geological structures: dykes, faults, fractures, joints, and weathered zones. Processed aeromagnetic datasets led to the identification of 990 lineaments that trend NE-SW and NW-SE. Approximately 63.32% of lineaments that trend the NE-SW lie between 40 ° and 70 °, while about 37.36% of the lineaments that trend NW-SE lie between 105° and 345°. Processed gridded radiometric dataset distinctively mapped all geological formations/groups, their contacts, alteration zones, dispersion pattern of varied concentration of K, T and U as radioelements. Areas of high lineament density, have high alteration and weathered zones, high K concentrations, low to moderate U and Th concentrations, and correspondingly high groundwater potentials and vice versa. Besides, lineaments and weathered zones showed elevated magnetic anomalies. Also, the presence of ferromagnesium minerals also gave rise to high magnetic anomalies while areas with felsic minerals show areas of low magnetic anomalies. Finally, although the various lineament delineated serve as channels for groundwater migration, the few laterally extensive lineaments that extend into the sea may serve as channels for groundwater contamination from the ingress of seawater resulting from the rise in sea levels due to global warming.