caa a22 4500 606149619 CHVBK 20210128100535.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s00531-014-1094-6 doi (NATIONALLICENCE)springer-10.1007/s00531-014-1094-6 Metal and fluid sources in a potential world-class gold deposit: El-Sid mine, Egypt [Elektronische Daten] [Hassan Helmy, Basem Zoheir] Lode gold mineralization at the El-Sid mine area is associated with the ca. 600Ma Fawakhir granite intrusion, which cuts the ~737Ma ophiolite nappes in the Central Eastern Desert of Egypt. The mineralized quartz veins are hosted by ~E- and NE-trending fault/fracture sets cutting the western boundary of the intrusion and sheared ophiolites. The results of electron microprobe analyses of gold-associated hydrothermal sulfide and silicate minerals suggest that Au was mobilized alongside Ni, Co, Cr and As from the adjacent ophiolitic serpentinite. After granite emplacement, hydrothermal fluids interacted with the sheared serpentinite, leaching metals and re-depositing them in the faults/fractures and adjacent wall rock in a cyclic process. Low-salinity aqueous-carbonic fluids with significant quantities of volatile species (CO2, CH4, and N2±H2S) leached and transported Au from deep to shallow crustal levels. Carbon dioxide had a buffering effect on the Au-bearing hydrothermal solution, maintaining its pH within a narrow near-neutral range, where elevated gold concentration was transported by complexation with reduced magmatic sulfur in a reducing environment. Gold deposition along fault/fracture conduits in the Fawakhir granite and adjacent serpentinite resulted from interplay of pressure drop, fluctuations in oxygen and sulfur fugacities, and exsolution of the volatile phases. Infiltration of meteoric water may have contributed to the formation of the late stage gold-sulfide mineralization that formed at shallower levels during terrane uplift. Sulfidation of the Fe-rich magmatic minerals was, on the other hand, the overriding process in the wall rock as evidenced by abundant disseminated sulfides with gold inclusions. Considering the structural control by regional shear zones (fluid conduits) and the voluminous granitic and ophiolitic rocks (metal sources), a high tonnage gold deposit amenable to open pit mining at the El-Sid mine area is very likely. Springer-Verlag Berlin Heidelberg, 2014 El-Sid gold deposit nationallicence Egypt nationallicence Metal and fluid sources nationallicence Deposition mechanism nationallicence Helmy Hassan Department of Geology, Minia University, 61519, Minia, Egypt aut Zoheir Basem Department of Geology, Faculty of Science, Benha University, 13518, Benha, Egypt aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/3(2015-04-01), 645-661 1437-3254 104:3<645 2015 104 531 https://doi.org/10.1007/s00531-014-1094-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1094-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Helmy Hassan Department of Geology, Minia University, 61519, Minia, Egypt aut NATIONALLICENCE 700 1- Zoheir Basem Department of Geology, Faculty of Science, Benha University, 13518, Benha, Egypt aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/3(2015-04-01), 645-661 1437-3254 104:3<645 2015 104 531