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Combinations of geological, geophysical and geochemical techniques have been used to explore gold deposits at Misaki within the Iramba-Sekenke Greenstone Belt (ISGB) in Singida region. The Misaki area is occupied by different rocks including homogeneous coarse-grained granite containing numerous xenoliths (> 5 vol. %), tonalite, K-rich granite and pegmatite, and dolerite dykes. All granitic rocks have been intruded by dolerite dykes, cut by epidote veins and are found juxtaposed to a tonalitic rock. Granitic rocks contain mainly anhedral to subhedral K-feldspar, plagioclase, quartz, biotite, hornblende, muscovite and opaque minerals, whereas tonalite contains similar minerals with relatively large amounts of plagioclase, biotite and hornblende (> 10 wt. %) and no K-feldspar. The rocks are weakly foliated to massive and poikilitic. K-feldspar is perthitic, whereas plagioclases have cores with rim overgrowths. Chlorite, plagioclase, epidote and sericite in the rock formed at the expense of primary minerals under greenschist facies conditions. Aeromagnetic data managed to identify lineaments that crosscut different rocks, from which NE-SW, NW-SE and ESE-WNW trends have been recognized. Results from radiometric data mapped different lithological units by their different K, U and Th contents distinguishing areas occupied by sediments or sedimentary rocks and those underlain by granitoid rocks. Soil geochemical survey has identified gold anomalies of up to 0.2 ppm Au that in parts associated with NE-SW trending lineaments. A follow-up detailed geological mapping work is recommended that would involve trenching and sampling of unweathered rocks, and documentation of geological structures to uncover potential gold deposits of the Misaki area within the Iramba-Senkenke Greenstone Belt (ISGB). |
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