Vertical Zoning and Geochemical Anomaly Fields of the Hamama Gold Deposit in the Central Part of Egypt’s Eastern Desert

Abstract: The Hamama deposit is represented by a steeply dipping massive sulfide orebody, located at the contact between basaltic lavas and their volcaniclastic varieties. It is about 3 km along strike, up to 110 m in thickness, and more than 250 m in depth. According to the documentation of cores from exploration boreholes, the vertical zoning of the ore zone was revealed, which consists of four zones (from bottom to top): 1, the primary ore zone; 2, secondary sulfide enrichment zone; 3, leaching zone; and 4, oxidation zone. The highest Au, Pb and Cu concentrations are distributed in the oxidation zone, while the highest Ag and Zn concentrations are observed in the massive primary ore at heights between 340 and 390 m. The oxidation zone is followed by a sharp metal depletion zone, then the metal content increases in the secondary enrichment zone and finally gradually decreases with thinning of the orebody. The interelement correlations between the base metals and Pb, Hg, Cd, As and Sb have been established, which reflect the polymetallic nature of the ore. Economic mineralization is grouped into two sectors: the Western and Eastern Hamama. The Western Hamama is more productive in terms of Au and Ag, while the Eastern Hamama hosts large amounts of Zn, Pb and Cu.