Browsing by Author "Saidi, H."

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    Geological controls on gold mineralization in tumbelo area, kondoa district, Central Tanzania
    (The University of Dodoma, 2023) Saidi, H.
    The geological controls on gold mineralization in Tumbelo area were studied by utilizing a combination of the high-resolution airborne geophysical, geochemical and geological data. The airborne magnetic, radiometric and gravity data were gridded, filtered and enhanced for better resolution and displayed in different map formats to characterize lithological units and delineate geological structures. Laboratory fire assay, XRF and thin-section analyses were performed to find gold concentrations and their associated elements. The aeromagnetic and gravity data identified E-W, N-S, NNE and NNW as the prominent trends of major and minor lineaments which control gold mineralization. Bouguer gravity identified a large body of density greater than 30 mgals which correlates with magnetic low in the northeastern part and is interpreted as a deep-seated major intrusive, and analytic signal identified minor intrusives which might be associated with gold mineralization. The 3D Euler and Werner deconvolutions estimated depths beneath the surface for geological structures and intrusives to range from less than 22.6 m deep to more than 1500 m deep. Radioelement concentrations show good correlation with mapped lithologies, and gold mineralization is spatially associated with elevated K/Th- (or low Th/K-) and U/K- ratios. Gold mineralization is structurally controlled and mainly occurs in steeply dipping sulphide-bearing quartz-carbonate veins which are typically hosted in plagioclase amphibolite and tremolite-actinolite schist. The Werner solutions reveal that gold mineralization is structurally associated with both the dykes and lithological contacts. The laboratory results show anomalous gold concentrations ranging from 0.022 to 2.26 ppm, and thin section examination showed that gold mineralization is mainly associated with carbonate-sericite-pyrite-silica alteration. The mobile elements such as As, Te, Cs, Cr, Cu and Zn show close association with gold and are considered as suitable pathfinder elements for gold mineralization in the study area. The result of this research will contribute onto address the knowledge and understanding of geological controls of gold mineralization in Tumbelo area and nearby areas with similar geology.