Genesis and evolution of the Hamama volcanic massive sulphide deposits, Egypt

Hamama Zn-Pb-Cu VMS deposits are hosted along the contact of bimodal metavolcanic sequence and their volcaniclastics in association with quartz-carbonate matrix. Ore forming process include multi-stage steps. 3D interpolation of drill hole database shows that the ore body was affected by multidirectional faults and fracture zones, that later were occupied by carbonates. The origin of carbonates is approached using a C and O isotopic compositions in whole-rock samples. The isotopic data revealed signs of both hydrothermal-sedimentary and hydrothermal-metasomatic processes. The primary gold and sulphide minerals were deposited from exhalations, forming massive sulphide ore then the tectonic processes due to the emergence of two successive phases of granitoids followed by the of post-tectonic dykes provided war to the introduction of carbonates that changed the configuration of the ore deposit and affected its grade. Later diagenetic and metasomatic processes resulted in enrichment of gold in the oxidation zone. © Published under licence by IOP Publishing Ltd.