Metallogeny of a Pan-African oceanic arc: VHMS and gold deposits in the Ariab-Arbaat belt, Haya terrane, Red Sea Hills (Sudan)

Gold in the Ariab district (Red Sea Hills, Sudan) is mined gossans developed over volcanogenic massive sulphide (VHMS) deposits formed context of a Tonian ensimatic arc Haiya terrane, Neoproterozoic Arabo-Nubian Shield. All primary gold occurrences belt, whatever their style (VHMS-, quartz lode- or shear-zone-hosted), appear, however, to have been syn-to late-kinematic, i.e., final Pan-African collision leading Arabian-Nubian Shield (D3 event), and therefore are post-VHMS. thus found associated with either galena bismuth telluride late syn- post-metamorphic sets (micro)cracks, mostly within earlier pyrite arsenopyrite. deposition as native electrum occurred when an intense fluid circulation metamorphic CO2-H2O rich fluids underwent significant decompression from lithostatic hydrostatic pressures at temperatures decreasing 400 430 °C around 8 km depth down 300 °C. Although no clear evidence volatile unmixing was observed, decompression, together temperature decrease due dilution by aqueous fluids, favoured deposition. The late-D3 event belt has all makings orogenic system, notably similar Late Carboniferous West European Variscan belt. Thus, it possible propose that, end events, released newly terrane root were channelled towards upper crust through major D3 shear zones such Oko zone. outpouring these drains then conveyed fault plays damaged zones, up specific chemical traps ore bodies veins systems. could be classified representative class deposits.