Nature and Geodynamic Setting of Late Neoproterozoic Vein-Type Gold Mineralization in the Eastern Desert of Egypt: Mineralogical and Geochemical Constraints

Abstract

The vein-type gold mineralization in the Eastern Desert of Egypt consists of sulphide minerals in stockwork quartz veins with hydrothermal alteration zones. The veins cut Neoproterozoic rocks along contacts between granite intrusions and island arc metavolcano-sedimentary sequence and ophiolitic rocks. Mineralization shows a clear structural control and is thus classified as orogenic gold. A post-peak metamorphic origin for the deposition of gold, sulphides, and carbonate gangue in the veins is suggested on the basis of various observations, such as: (1) gold mineralization is confined to quartz-bearing shear zones that cut host metamorphic rocks; (2) many sulphide minerals such as pyrite and arsenopyrite in addition to native gold and carbonate occur in different generations and parageneses; several of the sulphide generations are formed as a result of sulphidization of pre-existing metamorphic rocks; and (3) the depositional temperature of the hydrothermal minerals is commonly less than 400°C. Based on relationships to magmatism and geodynamic framework, the gold deposits formed during the post-collision stage (*640-590 Ma) of Neoproterozoic crustal evolution. Major and trace elements data for 848 gold-mineralized samples of host rocks and quartz veins are treated statistically utilizing multivariate methods including discriminant function and R-mode factor analyses. From the geochemical exploration point of view, the Au-mineralized alteration zones developed within granitoids and schists are the most

A Novel Approach for Resource Estimation of Highly Skewed Gold Using Machine Learning Algorithms

“…The gold mineralization and accompanying mineral alteration are extensively distributed throughout the shield's geological history. The overwhelming bulk of the gold resources in Egypt are of the orogenous vein-type [60]. The dominant host rocks are granites, mafic to ultramafic rocks, metavolcanic and volcanoclastic rocks, and metasediments [61].…”

Tectonic record and gold mineralization in the central part of the Neoproterozoic Keraf suture, Gabgaba district, NE Sudan

“…Most of the gold mineralization in the central KS is therefore coeval with the late tectonic formation of the KSZ overprinting the KS. At Nubian shield-scale, ~600 My-old gold mineralization hosted by quartz veins and related to ductile-brittle transcurrent structures is mostly characterized as orogenic gold (e.g., Elsamani et al, 2001;Klemm et al, 2001;Botros, 2002Botros, , 2004Helmy et al, 2004;El Kazzaz, 2012;Osman, 2014;Helmy and Zoheir, 2015;Khalil et al, 2016;Fawzy, 2017;Zoheir et al, 2019aZoheir et al, , 2019bZoheir et al, , 2019c.…”

“…1a, b) constitutes the main Neoproterozoic gold province worldwide (Johnson et al, 2017). ANS deposits are mostly classified as orogenic gold occurrences preferentially hosted by major shear zones (e.g., Elsamani et al, 2001;Botros, 2002Botros, , 2004Helmy et al, 2004;El Kazzaz, 2012;Osman, 2014;Helmy and Zoheir, 2015;Khalil et al, 2016;Fawzy, 2017;Zoheir et al, 2019aZoheir et al, , 2019bZoheir et al, , 2019c, including the Keraf shear zone (KSZ) (Johnson et al, 2017). The KSZ is mapped in northeastern Sudan and southeastern Egypt, and overprints the ~500 km-long, ~70 kmwide, north-striking ophiolite-decorated Keraf suture (KS) which is rooted deep into the lithosphere (Almond and Ahmed, 1987;Abdelrahman, 1993;Abdelsalam et al, 1995;Abdelsalam and Stern, 1996a;Ahmed Suliman, 2000).…”

New Occurrence of Gold Mineralization at the Eastern Part of Wadi El Gemal, South Eastern Desert, Egypt

“…A few studies have focused on the geochemical prospecting pattern and primary haloes of gold [8] [9] [10]. The vast majority of the Egyptian gold deposits belong to the orogenic vein type [11] [12] [13] [14]. Most of the auriferous veins are confined to granitic plutons that intruded metamorphosed ophiolite and/or arc-related rock assemblages [15]- [20].…”