Journal of Earth Sciences and Geotechnical Engineering

New Drilling Targets Identified Through Analysis of Geophysical and Geochemical Data from the Gawana and Sorbon Haoussa Sectors (Liptako, Southwest Niger)

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• Abstract

   

  Gold exploration within the permit area held by OM Goldstone Resources (covering the Gawana and Sorbon Haoussa sectors) in Niger’s Liptako mining province faces challenges common to the mining industry in Africa and elsewhere in the world: a decline in the discovery of new, economically viable deposits and the corresponding rise in exploration costs. Ground-based geophysical methods, combined with structural analysis and geological mapping, are now invaluable tools for enhancing the accuracy of exploration target selection and identifying potential drilling areas. A multi-technique methodological approach has been developed to identify areas with high mining potential. These include fieldwork, geophysics, and geochemistry investigations. Among these methods, ground geophysics provided important data to better characterise the study area. The geophysical work carried out as part of this study consisted of multi-frequency electromagnetic induction (EMI) surveys. Characterization and mapping of the subsurface electrical conductivity and magnetic susceptibility revealed various conductive veins, with variable alignments, that correspond to gold anomalies. The various conductive veins correspond either to acidic intrusive units (granodiorite/granite) and unmineralized quartz veins, or to sulphide-rich metasediments and grey quartz veins. Furthermore, the abundance of resistive units on the high-frequency map reveals intense weathering of the outcropping rocks; in the field, these correspond to alluvium derived from the weathering of manganiferous schists, as well as heavily weathered, sulfide-rich quartz veins. Consequently, the Gawana and Sorbon Haoussa sectors, located on the eastern edge of Niger's Liptako province, are expected to attract increased interest from gold exploration and development companies operating in the country.

   

  Keywords: Gold mineralisation, Geophysical surveys, New drilling targets, Gawana and Sorbon Haoussa sectors, Liptako province of Niger.