The structural control on the gold mineralization at the Galat Sufar South deposit (Block 14, NE Sudan)

The Galat Sufar South (GSS) gold deposit is an example of the Neoproterozoic gold potential of the Nubian Shield, especially along major sutures and shear zones such as the Keraf shear zone and the Atmur-Delgo suture. This study represents the first published work on the deposit and controls on mineralisation despite its strong gold endowment. This petro-structural study leads to consider a polyphase deformation history at the GSS gold deposit, from the cryptic D-1GSS and the principal D-2GSS (early development of the Keraf shear zone at the regional scale) ductile deformation events to the late, post-Keraf shear zone D-4GSS brecciation episode. The GSS gold mineralization is critically related to deformation. Indeed, the main D-2GSS deformation episode is expressed by both folding and shearing controlling the geometry of the main gold-bearing ore features, from disseminated pyrite to boudinaged quartz and sulphide-dominated veinlets. Later, the D-4GSS brecciation is responsible for the formation of a polymetallic ore, potentially resulting from the remobilization of the early mineralization. Therefore, the GSS gold deposit should be ultimately classified as a structurally controlled deposit.