Geophysical delineation of the geology and subsurface features of the Iramba area, central Tanzania, using aero-geophysical data with implications for mineral deposits

Abstract

The Iramba area, known for its gold, base metal, and metallic mineral deposits, is not geophysically well exploited. The research presents an in-depth geophysical interpretation of the geology and the subsurface geological features and delineates hydrothermal alteration zones related to mineralisation in the area. The study involved detailed analysis and interpretations of high-resolution aero–geophysical data. Results from radiometric data have identified new granitic rocks and revealed a unique prominent feature in the region, which was previously not mapped. The identified new xenolith and foliated granites are characterised by high concentrations of all radiometric elements. The revealed prominent ring-like, NE trending feature is characterised by a high K concentration with moderate to high Th concentration. The feature shows significantly lower values of the Th/U ratios at the centre than the surrounding with intermediate magnetic signatures at the centre surrounded by high magnetic signatures. The study has also delineated zones of high K that coincide with low Th and Th/K ratio, indicating hydrothermally altered rocks and mineralisation in the area. The practical implications of this study are the future exploration and development of mineral resources for small-scale miners or larger-scale industrial mining in areas where mineralisations have been proposed.