Abstract
The Sir Bakis area in the central Eastern Desert of Egypt hosts orogenic type gold deposits in shear-related, structurally controlled, quartz veins. These NNW–SSE-trending veins cross-cut Precambrian metavolcanics and granitoids of the Arabian Nubian shield that formed during the Pan-African Orogeny (780–610 Ma). The primary ore mineral assemblage consists of pyrite (As < 3.6%), chalcopyrite (Zn < 1.5%), galena (Zn < 0.2%, Te < 0.48%), sphalerite (7.9–8.9% Fe), magnetite (Ti, Cr, and Mn below detection), and gold (9–20% Ag). Gold also occurs as a texturally late mineral along with hessite (< 7% Au), silver, electrum (Au0.63Ag0.32), and covellite (Zn < 2.4%; Ag < 2.2%) that develop along rims and fractures of primary minerals. Three different types of fluid inclusions in vein quartz were observed: Type A are 3-phase (2 liquids + gas) solitary inclusions; Type B are 2-phase (liquid + gas) inclusions in clusters or isolated, and Type C are 2-phase (liquid + gas) inclusions in healed fractures mostly crossing grain boundaries. Microthermometric measurements show that eutectic melting points (Tme) for type A inclusions fall between − 63 and − 51 °C (most ~ − 56 °C), whereas type B inclusions have four distinct modes at − 66°, − 55°, − 35°, and − 22 °C. Type A inclusions record average clathrate melting temperatures of ~ 9.3 °C. All inclusions homogenize consistently through the disappearance of the vapor, with final homogenization temperatures (Th) for type B and C inclusions recorded at 263 and 240 °C, respectively. Analysis of microthermometric measurements on early type A and B fluid inclusions suggests that low salinity, CH4-bearing, aqueous-carbonic fluids (XH2O = 0.38–0.61; XCO2 = 0.26–0.53; XCH4 = 0.05–0.1; XNa+ = 0.005–0.013) were among the earliest trapped (in type A), followed by mostly aqueous, either CO2-bearing or CO2-free fluids (in type B inclusions; XH2O = 0.61–0.99; XCO2 < 0.04; XNa+ = 0.0006–0.025; XMg2+ = 0.01–0.13, XCa2+ < 0.0014, XCl− < 0.26). Ore-bearing fluids were likely CH4-bearing, aqueous-carbonic fluids similar to those trapped in type A inclusions. These fluids were likely metamorphic in origin, and leached Au from ultramafic and mafic ophiolitic rocks, carrying it in the form of bisulfide complexes. Ore minerals were precipitated upon oxidation as the fluids migrated to shallower crustal levels through the deep seated shear zones. Sphalerite thermobarometry and microthermometric analysis of early inclusions suggest that the primary ore mineral assemblage formed at T 280–300 °C, P > 4 kbar. Textural analysis of vein minerals and microthermometric measurements suggest that pyrite and galena likely recrystallized with quartz during late-stage deformation, leading to the reprecipitation of Au and Ag at T = 220–150 °C, P < 1 kbar. The two-stage evolution of Sir Bakis ore is consistent with genetic models proposed for many orogenic Au deposits that invoke subduction/collision followed by extension, and with the tectonic history of the central Eastern Desert which records regional metamorphism and intrusion of syncollisional magmas, followed by crustal extension, shearing, and post-orogenic magmatism.
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Abbreviations
- Brt:
-
Barite
- Cal:
-
Calcite
- Ccp:
-
Chalcopyrite
- Cv:
-
Covellite
- CED:
-
Central eastern Desert
- ED:
-
Eastern Desert
- El:
-
Electrum
- Gn:
-
Galena
- Goe:
-
Goethite
- Hs:
-
Hessite
- Kln:
-
Kaolinite
- Py:
-
Pyrite
- Qz:
-
Quartz
- Mgt:
-
Magnetite
- Spl:
-
Sphalerite
- Tme :
-
Initial melting temperature of ice
- Tmf :
-
Final melting of ice
- T h :
-
Homogenization temperature
References
Abdelkareem M, Al-Arifi N (2021) Synergy of remote sensing data for exploring hydrothermal mineral resources using GIS-based Fuzzy Logic approach. Remote Sens 13(22):4492. https://doi.org/10.3390/rs13224492
Abdelkareem M, Kamal El-Din GM, Osman I (2018) An integrated approach for mapping mineral resources in the Eastern Desert of Egypt. Int J Appl Earth Obs Geoinf 73:682–696
Abd El Monsef M, Slobodník M, Salem AI (2018) Hydrothermal evolution of granitoid-hosted gold mineralization in Gidami area: An example for orogenic-gold deposits in Egypt. J Afr Earth Sci 14:132–149
Afifi AM, Kelly WC, Essene EJ (1988) Phase relations among tellurides, sulphides and oxides: I. Thermochemical data and calculated equilibria; II. Applications to telluride-bearing ore deposits. Econ Geol 83:377–404
Al-Arifi N, Kamal El-Din G, Abdelkareem M, Abdalla F (2021) Integration of remote-sensing, structural, and geochemical data for characterizing granitoid rocks in Um Naggat pluton, Central Eastern Desert. Egypt Arab J Geosci 14(50):1–22. https://doi.org/10.1007/s12517-020-06274-x
Amin MS (1955) Geological features of some mineral deposits of Egypt. Desert Bull Inst 5:208–239
Akaryali E, Tüysüz N (2013) The genesis of the slab window-related Arzular low-sulfidation epithermal gold mineralization (eastern Pontides, NE Turkey). Geosci Front 4:409–421
Audétat A, Günther D (1999) Mobility and H2O-loss from fluid inclusions in natural quartz crystals. Contrib Mineral Petrol 137:1–14
Banno S (1988) On the sphalerite geobarometer. Geochem J 22:129–131
Bakker RJ (1997) CLATHRATES: Computer programs to calculate fluid inclusion V-X properties using clathrate melting temperatures. Comput Geosci 23:1–18
Bakker RJ (1999) Adaptation of the Bowers and Helgeson (1983) equation of state to the H2O-CO2-CH4-N2-NaCl system. Chem Geol 154:225–236
Bakker RJ (2003) Package FLUIDS 1. Computer programs for analysis of fluid inclusion data and for modelling bulk fluid properties. Chem Geol 194:3–23
Barker AJ (1995) Post-entrapment modification of fluid inclusions due to overpressure: evidence from natural samples. J Metamorph Geol 13:737–750
Shi-Jian Bi, Jian-Wei Li, Mei-Fu Z, Zhan-Ke Li (2011) Gold distribution in As-deficient pyrite and telluride mineralogy of the Yangzhaiyu gold deposit, Xiaoqinling district, southern North China craton. Miner Depos 46:925–941
Bodnar RJ, Hall BPR, DL, (1989) Synthetic fluid inclusions-VI. Quantitative evaluation of the decrepitation behaviour of fluid inclusions in quartz at one atmosphere confining pressure. J Metamorph Geol 7:229–242
Bogdanov K, Filipov A, Kehayov R (2005) Au-Ag-Te-Se minerals in the Elatsite porphyry-copper deposit, Bulgaria. Geochem Mineral Petrol 42:14–19
Botros NS (2002) Metallogeny of gold in relation to the evolution of the Nubian Shield in Egypt. Ore Geol Rev 19:137–164
Botros NS (2004) A new classification of the gold deposits of Egypt. Ore Geol Rev 25:1–37
Bowers TS, Helgeson HC (1983) Calculation of thermodynamic and geochemical consequences of nonideal mixing in the system H2O–CO2–NaCl on phase relations in geologic systems: equation of state for H2O–CO2–NaCl fluids at high pressures and temperatures. Geochim Cosmochim Acta 47:1247–1275
Breitkreuz C, Eliwa H, Khalaf I, El Gameel K, Bühler B, Segeev S, Larionov A, Murata M (2010) Neoproterozoic SHRIMP U-Pb zircon ages of silica-rich Dokhan Volcanics in the Northeastern Desert. Egypt Precambrian Res 182:163–174
Cabri LJ (1965) Phase relations in the Au-Ag-Te system and their mineralogical significance. Econ Geol 60:1569–1606
Chi G, Xue C (2011) Abundance of CO2-rich fluid inclusions in a sedimentary basin-hosted Cu deposit at Jinman, Yunnan, China: implications for Cu transport and mineralization. Miner Depos 46:365–380
Conoco, (1987) Geological Map of Egypt, Scale 1:500,000. The Egyptian General Petroleum Corporation, Cairo, Egypt
Crocket JH, Chyi LL (1972) Abundances of Pd, Ir, Os and Au in an alpine ultramafic pluton. Proc 24th Int Geol Congr Sect 10:202–209
Crocket JH (1991) Distribution of gold in the Earth’s crust, in Gold metallogeny and exploration. In: Foster RP (ed) Gold Metallogeny and Exploration. Chapman and Hall, London, pp 1–36
Dalziel IWD, Lawver LA, Murphy JB (2000) Plumes, orogenesis, and supercontinental fragmentation. Earth Planet Sci Lett 178:1–11
Diamond LW (1994) Salinity of multivolatile fluid inclusions determined from clathrate hydrate stability. Geochim Cosmochim Acta 58:19–41
Diamond LW (2003) Introduction to gas bearing, aqueous fluid inclusions. In: Samson I, Anderson A, Marshall D (eds) Fluid inclusions: analysis and interpretation. Mineral Assoc Canada 32:101–158
Dugdale AL, Hagemann SG (2001) The Bronzewing lode-gold deposit, Western Australia: P-T-X evidence for fluid immiscibility caused by cyclic decompression in gold-bearing quartz veins. Chem Geol 173:59–90
EI-Bouseily A M, EI-Dahhar MA, Arslan AI, (1985) Ore-microscopic and geochemical characteristics of gold-bearing sulfide minerals, El Sid Gold Mine, Eastern Desert. Egypt Miner Depos 20:194–200
El Gaby S, List FK, Tehrani R (1990) The basement complex of the Eastern Desert and Sinai. In: Said R (ed) The Geology of Egypt. Balkema, Rotterdam, pp 175–184
El Ramly MF (1972) A new geological map for the basement rocks in the Eastern and south Western Deserts of Egypt, scale 1:1,000,000. Ann Geol Surv Cairo 2:1–18
El-Shazly AK, Khalil KI (2014) Banded Iron Formations of Um Nar, Eastern Desert of Egypt: P-T-X conditions of metamorphism and tectonic implications. Lithos 196:356–375
El-Shazly AK, Khalil KI (2016) Metamorphic and Geochronologic constraints on the tectonic evolution of the Central Eastern Desert of Egypt: implications for origin of some Neoproterozoic Banded Iron Formations. Precambrian Res 283:144–168
El-Shazly AK, Khalil KI, Helba HA (2019) Geochemistry of banded iron formations and their host rocks from the Central Eastern Desert of Egypt: a working genetic model and tectonic implications. Precambrian Res 325:192–216
Essene EJ (1982) Geologic thermometry and barometry. Characterization of metamorphism through mineral equilibria. In: Ferry JM (eds) Reviews of Mineralogy. Mineralogical Soc America 10:153–206
Evans AM (1993) Ore geology and industrial minerals: An introduction, 3rd edn. Blackwell Scientic Public, Oxford/Boston, p 400
Fielding IO, Johnson SP, Zi JW, Rasmussen B, Sheppard S (2020) Gold metallogeny of the northern Capricorn Orogen: The relationship between crustal architecture, fault reactivation and hydrothermal fluid flow. Ore Geol Rev 122(103515):1–17
Ghoneim MF, Heikal MTh, S., El Dosuky, B. T., Abu-Alam, T., Sherif, M. I. (2015) Neoproterozoic granites of Sharm El-Sheikh area, Egypt: mineralogical and thermobarometric variations. Arab J Geosci 8:125–141
Goldstein RH, Reynolds TJ (1994) Systematics of Fluid Inclusions in Diagenetic Minerals, SEPM Short Course. Soc Sed Geol., Tulsa. 31, pp 199
Gottesmann W, Kampe A (2007) Zn/Cd ratios in calcsilicate—hosted sphalerite ores at Tumurtijn-ovoo, Mongolia. Chem Erde 67:323–328
Groves DI, Goldfarb RJ, Gebre-Mariam M, Hagemann SG, Robert F (1998) Orogenic gold deposits: a proposed classification in the context of their crustal deformation and relationship to other gold deposit types. Ore Geol Rev 13:7–28
Groves DI, Goldfarb RJ, Robert F, Hart CJR (2003) Gold deposits in metamorphic belts: overview of current understanding, outstanding problems, future research, and exploration significance. Econ Geol 98:1–29
Guilbert JM, Park CF (1986) The Geology of Ore Deposits. W. H. Freeman and Company, New York, pp 985
Hall DL, Sterner MS (1993) Preferential water loss from synthetic fluid inclusions. Contrib Mineral Petrol 114:489–500
Hassan MA, Hashad AH (1990) Precambrian of Egypt. In: Said R (ed) The Geology of Egypt. Balkema, Rotterdam, pp 201–245
Hassanein, M.M., 1994. Geology and gold mineralization of Abu Marawat area, Central Eastern Desert, Egypt. MSc thesis. Al Azhar Univ, Cairo, Egypt, pp 183
Hazarika P, Mishra B, Pruseth KL (2017) Trace-element geochemistry of pyrite and arsenopyrite: ore genetic implications for late Archean orogenic gold deposits in southern India. Mineral Mag 81(3):661–678
Heald P, Foley N, Hayba D (1987) Comparative anatomy of volcanic-hosted epithermal deposits: acide-sulfate and adularia-sericite types. Econ Geol 82:1–26
Helmy HM, Ahmed AF, Al Mahallawi MM, Ali SM (2004) Pressure, temperature and oxygen fugacity conditions of calc-alkaline granitoids and tectonic implications, Eastern Desert of Egypt. J Afr Earth Sci 38:255–268
Henley RW (1993) Epithermal gold deposits in volcanic terranes. In: Foster RP (ed) Gold metallogeny and exploration. Chapman and Hall, London, pp 133–164
Hickman S, Sibson R, Bruhn R (1995) Introduction to special section: Mechanical involvement of fluids in faulting. J Geophys Res 100(B7):12831–12840
Ho SE, McQueen KG, McNaughton NJ, Groves DI (1995) Lead isotope systematics and pyrite trace element geochemistry of two granitoid associated mesothermal gold deposits in the southern Lachlan fold belt. Econ Geol 90:1818–1830
Kant W, Warmada IW, Idrus A, Setijadji LD, Watanabe K (2012) Fluid inclusion study of the polymetallic epithermal quartz veins at Soripesa prospect area, Sumbawa Island. Indonesia J SE Asian Appl Geol 4(2):77–89
Keith M, Haase KM, Schwarz-Schampera U, Klemd R, Petersen S, Bach W (2014) Effects of temperature, sulfur, and oxygen fugacity on the composition of sphalerite from submarine hydrothermal vents. Geol 42:699–702
Kerrich R, La Tour TE, Willmore L (1984) Fluid participation in deep fault zones: Evidence from geological, geochemical, and 18O/16O relations. J Geophys Res 89:43331–43433
Klemm R, Klemm D (2013) Gold and gold mining in ancient Egypt and Nubia: Geoarchaeology of the ancient gold mining sites in the Egyptian and Sudanese Eastern Deserts. Heidelberg: Springer pp 649
Kochine GG, Bassiuni FA (1968) Mineral resources of the U.A.R.: Part I. Metallic minerals, Interact. Rep. Geol Surv Egypt pp 305–436
Kröner A, Stern RJ (2004) Pan-African Orogeny Encyclop Geol 1:1–12
Lang JR, Baker T (2001) Intrusion related gold systems- the present level of understanding. Miner Depos 36:477–489
Loizenbauer J, Wallbrecher E, Fritz H, Neumayr P (2001) Structural geology, single zircon ages and fluid inclusion studies of the Meatiq metamorphic core complex: implications for Neoproterozoic tectonics in the Eastern Desert of Egypt. Precambrian Res 110(1):357–383
Liu Z, Shao Y, Zhou H, Liu N, Huang K, Liu Q, Zhang J, Wang C (2018) Major and trace element geochemistry of pyrite and pyrrhotite from stratiform and lamellar ore bodies: implications for the ore genesis of the Dongguashan Copper (Gold) deposit. Eastern China Minerals 8(380):1–20
Lundmark AM, Andresen A, Hassan MA, Augland LE, Boghdady GY (2012) Repeated magmatic pulses in the East African Orogen of Central Eastern Desert, Egypt: an old idea supported by new evidence. Gondwana Res 22:227–237
Lusk J, Ford CE (1978) Experimental extension of the sphalerite geobarometer to 10 kbar. Am Miner 63:516–519
Martín JD, Gil AS (2005) An integrated thermodynamic mixing model for sphalerite geobarometry from 300 to 850°C and up to 1 GPa. Geochim Cosmochim Acta 69:995–1006
Martin BE (1986) Reconnaissance of the gold deposits of the Eastern Desert of Egypt. Geol. Surv. of Egypt, Inter. Rep. No. 39/1986, pp 144
Mikucki EJ (1998) Hydrothermal transport and depositional processes in Archean lode-gold systems: a review. Ore Geol Rev 13:307–321
Moharram O, El-Ramly MF, Amer AF, Ivanov SS, Gachechiladze DZ (1970) Studies on some mineral deposits of Egypt (summary of the results of the work carried out by a team of Egyptian and Soviet geologists under contract 1247). Egypt Geol Surv pp 269
Moussa EMM, Stern RJ, Manton WI, Ali KA (2008) SHRIMP zircon dating and Sm/Nd isotopic investigations of Neoproterozoic granitoids, Eastern Desert. Egypt Precambrian Res 160:341–356
Neumayr P, Hoinkes G, Puhl J, Mogessie A, Khudeir AA (1998) The Meatiq dome (Eastern Desert, Egypt) a Precambrian metamorphic core complex: petrological and geological evidence. J Metamorph Geol 16:259–279
Roedder E (1982) Possible Permian diurnal periodicity in NaCl precipitation, Palo Duro basin, Texas. In: Gustavson TC et al (eds) Geology and Geohydrology of the Palo Duro Basin, Texas Panhandle, Bureau of Economic Geology. The University of Texas at Austin, Geological Circular 82–7, 104
Sabeva R, Mladenova V, Mogessie A (2017) Ore petrology, hydrothermal alteration, fluid inclusions, and sulfur stable isotopes of the Milin Kamak intermediate sulfidation epithermal Au-Ag deposit in Western Srednogorie, Bulgaria. Ore Geol Rev 88:400–415
Said R (1971) Explanatory notes to accompany the geological map of Egypt. The Geological Survey of Egypt, Paper No. 56,
Scott SD (1973) Experimental calibration of the sphalerite geobarometer. Econ Geol 68:466–474
Scott SD (1976) Application of the sphalerite geobarometer to regionally metamorphosed terrains. Am Miner 61:661–670
Shackleton JM, Spry PG, Bateman R (2003) Telluride mineralogy of the golden mile deposit, Kalgoorlie. Western Australia Canad Mineral 41(6):1503–1524
Shalaby A, Stuwe K, Makroum F, Fritz H, Kebede T, Klotzli U (2005) The wadi Mubarak belt, Eastern Desert, Egypt: a Neoproterozoic conjugate shear system in the Arabian-Nubian Shield. Precambrian Res 136(1):27–50
Shi X, Al-Arifi N, Abdelkareem M, Abdalla F (2020) Application of remote sensing and GIS techniques for exploring potential areas of hydrothermal mineralization in the central Eastern Desert of Egypt. J Taibah Univ Sci 14:1421–1432
Simon G, Essene EJ (1996) Phase relations among selenides, sulfides, tellurides, and oxides. I. Thermodynamic properties and calculated equilibria. Econ Geol 91:1183–1208
Stern RJ, Hedge CE (1985) Geochronologic and isotopic constraints on Late Precambrian crustal evolution in the Eastern Desert of Egypt. Am J Sci 285:97–127
Stüwe K, Will T, Zhou S (1993) On the timing relationship between fluid production and metamorphism in metamorphic piles: some implications for the origin of post-metamorphic gold mineralization. Earth Planet Sci Lett 114:417–430
Tosdal RM, Dilles JH, Cooke DR (2009) From source to sinks in auriferous magmatic-hydrothermal porphyry and epithermal deposits. Elements 5(5):289–295
Toulmin P, Barton PB Jr, Wiggins LB (1991) Commentary on the sphalerite geobarometer. Am Miner 76(5–6):1038–1051
Vityk MO, Bodnar RJ, Schmidt CS (1994) Fluid inclusions as tectonothermobarometers: relation between pressure-temperature history and reequilibration morphology during crustal thickening. Geol 22:731–734
Voudouris PC, Melfos V, Spry PG, Bindi L, Kartal T, Arikas K, Moritz R, Ortelli M (2009) Rhenium-rich molybdenite and rheniite (ReS2) in the Pagoni Rachi-Kirki Mo-Cu-Te-Ag-Au deposit, Northern Greece: Implications for the rhenium geochemistry of porphyry style Cu-Mo and Mo mineralization. Canad Mineral 47:1013–1036
Xavier RP, Foster RP (1999) Fluid evolution and chemical controls in the Fazenda Maria Preta (FMP) gold deposit. Rio Itapicuru Greenstone Belt, Bahia, Brazil, Chem Geol 154:133–154
Xuexin S (1984) Minor elements and ore genesis of the Fankou Lead-Zinc deposit, China. Miner Depos 19:95–104
Zhai D, Liu J (2014) Gold-telluride-sulfide association in the Sandaowanzi epithermal Au-Ag-Te deposit, NE China: implications for phase equilibrium and physicochemical conditions. Miner Petrol 108:853–871
Zhang Y, Frantz D (1987) Determination of the homogenization temperatures and densities of supercritical fluids in the system NaCl-KCl-CaCl2-H20 using synthetic fluid inclusions. Chem Geol 64:335–350
Zheng Y, Mao J, Chen Y, Sun W, Ni P, Yang X (2019) Hydrothermal ore deposits in collisional orogens. Sci Bull 64(3):205–212
Zoheir BA, El-Shazly AK, Helba H, Khalil KI, Bodnar RA (2008) Origin and evolution of the Um Egat and Dungash Orogenic Gold Deposits, Egyptian Eastern Desert: Evidence from fluid inclusions in quartz. Econ Geol 103:405–424
Zoheir BA, Akawy A (2010) Genesis of the Abu Marawat gold deposit, Central Eastern Desert of Egypt. J Afr Earth Sci 57:306–320
Zoheir BA, Johnson PR, Goldfarb RJ, Klemm DD (2019) Orogenic gold in the Egyptian Eastern Desert: Widespread gold mineralization in the late stages of Neoproterozoic orogeny. Gondwana Res 75:184–217
Acknowledgements
The authors would like to extend their sincere appreciation the Ministry of Higher Education, Egypt and USAID program for funding this research and arranging for Abdelkareem's sabbatical stay at Marshall University. David Neff is thanked for his assistance with SEM maintenance, mounting standards, valuable advice, and some aspects of analysis. Detailed reviews by Professor A. Chauvet and J. Moyen improved this paper substantially. An earlier version of this manuscript benefited from reviews by Profs. Oliver Kruzer and Richard Goldfarb. Any remaining errors are the sole responsibility of the authors.
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Abdelkareem, M., El-Shazly, A.K. Gold–sulfide mineralization in the Sir Bakis mine area, Central Eastern Desert, Egypt. Int J Earth Sci (Geol Rundsch) 111, 861–888 (2022). https://doi.org/10.1007/s00531-021-02154-1
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DOI: https://doi.org/10.1007/s00531-021-02154-1