Résumé
The Barberton Greenstone Belt (BGB) containsover 350 gold occurrences and an estimated production of342 tons, mainly from Fairview, New Consort, Sheba andAgnes mines. Many studies target these active mines tounderstand gold mineralisation. This study focuses on thedistribution and structural control of hydrothermal veins,including in old mining areas and low-grade goldoccurrences. The gold-bearing event is studied usingspatial statistical analysis combined with structural fieldgeology and mineralogical analysis. Thehydrothermal/gold occurrences are distributed in severalclusters. Two main tectonic events are involved in theformation of hydrothermal veins. A main deformation eventrelated to large-scale folding and thrusting controlsemplacement of gold-bearing veins during a single orpulsed NW-SE shortening in the northern BGB, and duringan E-W shortening in the southern BGB. A latedeformation event, produced by NE-SW shortening in thesouthern BGB is also related to late hydrothermal quartzveins. Quartz-carbonate veins are found in the northernmineralised system, whereas quartz-tourmaline-feldsparscarbonate+/- sulfides veins are present mainly in thesouthern BGB. The mineralised event in the BGB isstructurally controlled by the main NW-SE to E-Wshortening whereas additional quartz systems, not The Barberton Greenstone Belt (BGB) containsover 350 gold occurrences and an estimated production of342 tons, mainly from Fairview, New Consort, Sheba andAgnes mines. Many studies target these active mines tounderstand gold mineralisation. This study focuses on thedistribution and structural control of hydrothermal veins,including in old mining areas and low-grade goldoccurrences. The gold-bearing event is studied usingspatial statistical analysis combined with structural fieldgeology and mineralogical analysis. Thehydrothermal/gold occurrences are distributed in severalclusters. Two main tectonic events are involved in theformation of hydrothermal veins. A main deformation eventrelated to large-scale folding and thrusting controlsemplacement of gold-bearing veins during a single orpulsed NW-SE shortening in the northern BGB, and duringan E-W shortening in the southern BGB. A latedeformation event, produced by NE-SW shortening in thesouthern BGB is also related to late hydrothermal quartzveins. Quartz-carbonate veins are found in the northernmineralised system, whereas quartz-tourmaline-feldsparscarbonate+/- sulfides veins are present mainly in thesouthern BGB. The mineralised event in the BGB isstructurally controlled by the main NW-SE to E-Wshortening whereas additional quartz systems, notThe Barberton Greenstone Belt (BGB) containsover 350 gold occurrences and an estimated production of342 tons, mainly from Fairview, New Consort, Sheba andAgnes mines. Many studies target these active mines tounderstand gold mineralisation. This study focuses on thedistribution and structural control of hydrothermal veins,including in old mining areas and low-grade goldoccurrences. The gold-bearing event is studied usingspatial statistical analysis combined with structural fieldgeology and mineralogical analysis. Thehydrothermal/gold occurrences are distributed in severalclusters. Two main tectonic events are involved in theformation of hydrothermal veins. A main deformation eventrelated to large-scale folding and thrusting controlsemplacement of gold-bearing veins during a single orpulsed NW-SE shortening in the northern BGB, and duringan E-W shortening in the southern BGB. A latedeformation event, produced by NE-SW shortening in thesouthern BGB is also related to late hydrothermal quartzveins. Quartz-carbonate veins are found in the northernmineralised system, whereas quartz-tourmaline-feldsparscarbonate+/- sulfides veins are present mainly in thesouthern BGB. The mineralised event in the BGB isstructurally controlled by the main NW-SE to E-Wshortening whereas additional quartz systems, not mineralised, seem to be controlled by an enigmatic NESWshortening.