Silver- and silver-bearing minerals from the precambrian volcanogenic massive sulfide deposit, Um Samiuki, Eastern Desert, Egypt

摘要

The Um Samiuki deposit is a Precambrian volcanogenic massive sulfide mineralization. Massive and disseminated Zn-Cu-Pb-Ag sulfides are hosted in felsic volcanics and pyroclastics. The ores show primary depositional and metamorphic-deformational features. The hypogene sulfides comprise sphalerite, chalcopyrite, galena, tetrahedrite-tennantite, pyrite, bornite, arsenopyrite and molybdenite, whereas covellite is a supergene phase. Bornite, tetrahedrite-tennantite and covellite are generally Ag-rich with an average Ag contents of 0.76, 0.82, and 1.69 wt.