|
Egypt | |
| Mohamed, A. (2013). Mineral chemistry and genesis of Zr, Th, U, Nb, Pb, P, Ce and F enriched peralkaline granites of El-Sibai shear zone, central Eastern Desert, Egypt. |
| J.C. Bridges, M.M. Grady (2000) Evaporite mineral assemblages in the nakhlite (martian) meteorites. Earth and Planetary Science Letters 176:267-279 Berkley, J. L., Keil, K., & Prinz, M. (1980) Comparative petrology and origin of Governador Valadares and other nakhlites. In: Lunar and Planetary Science Conference, 11th, Houston, TX, March 17-21, 1980, Proceedings. Volume 2. (A82-22296 09-91) New York, Pergamon Press, 1980, p. 1089-1102. |
| Marco Marchesini & Antonello Barresi (2019) The Wadi Natrun evaporite deposits, Western Desert, Buhayra Governate, Egypt. Mineralogical Record 50:723-748 Marchesini, M., Barresi, A. (2009) I minerali di Wadi natrun, Deserto Occidentale, Egitto, Rivista Mineralogica Italiana, 4/2009, 228-258. |
| S. Tosson et al. , Bull. Soc. Fr. Minéral. Cristallogr. , 1974, 97, pp. 27-39. |
| Alfredo Petrov collection (collected by Alain Carion) |
| Lasheen, El Saeed R., Hesham M. H. Zakaly, B. M. Alotaibi, Diaa A. Saadawi, Antoaneta Ene, Douaa Fathy, Hamdy A. Awad, and Raafat M. El Attar. 2022. "Radiological Risk Parameters of the Phosphorite Deposits, Gebel Qulu El Sabaya: Natural Radioactivity and Geochemical Characteristics" Minerals 12, no. 11: 1385. https://doi.org/10.3390/min12111385 |
| Abd El Monsef, M. (2019) Ore Controls and Metallogenesis of Au‐Ag Deposits at Atalla Mine, Central Eastern Desert of Egypt. Acta Geologica Sinica‐English Edition. Zoheir, B., Deshesh, F., Broman, C., Pitcairn, I., El-Metwally, A., & Mashaal, S. (2018). Granitoid-associated gold mineralization in Egypt: a case study from the Atalla mine. Mineralium Deposita, 53(5), 701-720. |
| Econ Geol (1987) 82:767-772 Osman A. M., Pieczonka J., Piestrzyński A. 2002: Relationships between gold and tellurides in the El Sid gold deposit, Eastern Desert, Egypt. Mineralogia Polonica, vol. 33, no 2, 15-26 |
| Abdel‐Karim, A. A. M., & El‐Shafei, S. A. (2018). Mineralogy and chemical aspects of some ophiolitic metaultramafics, central Eastern Desert, Egypt: Evidences from chromites, sulphides and gangues. Geological Journal, 53(2), 580-599. |
| El-Desoky, Hatem M., Ahmed M. Abdel-Rahman, Wael Fahmy, Ibrahim Khalifa, Salah A. Mohamed, Aref Shirazi, Ardeshir Hezarkhani, Adel Shirazy, and Amin Beiranvand Pour. (2023) "Ore Genesis of the Abu Ghalaga Ferro-Ilmenite Ore Associated with Neoproterozoic Massive-Type Gabbros, South-Eastern Desert of Egypt: Evidence from Texture and Mineral Chemistry" Minerals 13, no. 3: 307. https://doi.org/10.3390/min13030307 |
| Abdalla, H. M. (2006). An Overview on the REE‐Mineralized Alkaline Granites in Egypt, with Special Reference to the Abu Khruq and Gara El Hamra Bodies. Resource Geology, 56(3), 365-370. |
| Basem A. Zoheir & Ahmed Akawy (2010): Genesis of the Abu Marawat gold deposit, central Eastern Desert of Egypt. Journal of African Earth Sciences 57, 306-320. Smillie (nee Taman), Z., Scott, P. W., Osman, A. M. M., & Hilmy, M. E. (2002). Mineralogy and geochemistry of some Proterozoic Banded Iron Formations from the Eastern Desert of Egypt. In 18th International Mineralogical Association Congress |
| El Aref, M., Abd El-Rahman, Y., Zoheir, B., Surour, A., Helmy, H. M., Abdelnasser, A., ... & Ibrahim, M. E. A. (2020). Mineral Resources in Egypt (I): Metallic Ores. In The Geology of Egypt (pp. 521-587). Springer, Cham. |
| El-Wardany, Refaey M., Jiangang Jiao, Basem Zoheir, Mustafa Kumral, Mustafa Kaya, and Amr Abdelnasser. (2023) "Post-Subduction Granite Magmatism and Gold-Sulfide Mineralization in the Abu Zawal (Fatira) Area, Eastern Desert, Egypt" Minerals 13, no. 4: 489. https://doi.org/10.3390/min13040489 |
| Abdelnasser, A., Kumral, M. (2017) The nature of gold-bearing fluids in Atud gold deposit, Central Eastern Desert, Egypt. International Geology Review, 59:15, 1845-1860. Harraz, H. Z. (2002): Journal of African Earth Sciences, 35, 347-363 Hassan Z. Harraz (2002) Fluid Inclusions in the Mesozonal Gold Deposit at Atud Mine, Eastern Desert, Egypt. Journal of African Earth Sciences 35:347-363 |
| Abdel‐Karim, A. A. M., & El‐Shafei, S. A. (2018). Mineralogy and chemical aspects of some ophiolitic metaultramafics, central Eastern Desert, Egypt: Evidences from chromites, sulphides and gangues. Geological Journal, 53(2), 580-599. |
| Basem Zoheir and Bernd Lehmann (2011): Listvenite–lode association at the Barramiya gold mine, Eastern Desert, Egypt. Ore Geology Reviews 39, 101-115. |
| Smillie (nee Taman), Z., Scott, P. W., Osman, A. M. M., & Hilmy, M. E. (2002). Mineralogy and geochemistry of some Proterozoic Banded Iron Formations from the Eastern Desert of Egypt. In 18th International Mineralogical Association Congress |
| Ore Geology Reviews 34 (2008) 580-596. |
| Khairiya M. Fawzy (2017): Ore Mineralogical and Geochemical Studies on El-Daghbag-I Gold Deposit, Central Eastern Desert, Egypt. Open Journal of Geology 7 (3), 395-419. |
| Gatto Rotondo, G., Darchuk, L., Swaenen, M., & Van Grieken, R. (2012). Micro-Raman and SEM analysis of minerals from the Darhib mine, Egypt. Journal of analytical sciences, methods and instrumentation, 2(1), 42-47. |
| Zoheir, Basem & Weihed, Pär. (2013) Greenstone-hosted lode-gold mineralization at Dungash mine, Eastern Desert, Egypt. Journal of African Earth Sciences. 10.1016/j.jafrearsci.2013.06.002. B. A. Zoheir, A. K. El-Shazly, H. Helba, K. I. Khalil and R. J. Bodnar (2008) Origin and evolution of the Um Egat and Dungash orogenic gold deposits, Egyptian Eastern Desert evidence from fluid inclusions in quartz. Economic Geology and the Bulletin of the Society of Economic Geologists 103:405-424 |
| El-Naby, H. H. A. (2009). Role of geochemical alteration on the formation of secondary Zr-and U-bearing minerals in El Atshan trachyte, central Eastern Desert, Egypt. Journal of Mineralogical and Petrological Sciences, 104(1), 37-51. |
| El Aref, M., Abd El-Rahman, Y., Zoheir, B., Surour, A., Helmy, H. M., Abdelnasser, A., ... & Ibrahim, M. E. A. (2020). Mineral Resources in Egypt (I): Metallic Ores. In The Geology of Egypt (pp. 521-587). Springer, Cham. Mineral. Deposita 43 (2008) 933-944. |
| Atef, Abdallah, Surour, Adel A., Madani, Ahmed A., Azer, Mokhles K. (2023) Au-Cu Resources in Some Mines from Antiquity in the South Gabal Um Monqul and Gabal Al Kharaza Prospects, North Eastern Desert, Egypt. Geosciences, 13 (9) doi:10.3390/geosciences13090283 |
| Abdel‐Karim, A. A. M., & El‐Shafei, S. A. (2018). Mineralogy and chemical aspects of some ophiolitic metaultramafics, central Eastern Desert, Egypt: Evidences from chromites, sulphides and gangues. Geological Journal, 53(2), 580-599. |
| El Aref, M., Abd El-Rahman, Y., Zoheir, B., Surour, A., Helmy, H. M., Abdelnasser, A., ... & Ibrahim, M. E. A. (2020). Mineral Resources in Egypt (I): Metallic Ores. In The Geology of Egypt (pp. 521-587). Springer, Cham. Helmy, H.M., and Mogessie, A. (2001): Mineralium Deposita 36, 58-71. Sharara, N. A., Wilson, G. C., & Rucklidge, J. C. (1999). Platinum-group elements and gold in Cu-Ni-mineralized peridotite at Gabbro Akarem, Eastern Desert, Egypt. Canadian Mineralogist, 37(5), 1081-1098. |
| Nagar, M. S., Kamal, H. M., El Monsif, A. M., & Ghazala, R. A. (2020). Potential uranium recovery by percolation leaching from El Missikat mineralized silica vein, Eastern Desert, Egypt. Academic Journal of Environmental Science, 8(5), 71-80. |
| Feteha, B. F., Lentz, D. R., El Bouseily, A. M., Khalil, K. I., Khamis, H. A., & Moghazi, A. K. M. (2022). Petrogenesis of neoproterozoic Mo-bearing A-type granites in the Gattar area, northern Eastern Desert, Egypt: Implications for magmatic evolution and mineralization processes. Ore Geology Reviews, 148, 105007. Helmy, H. M., & Kaindl, R. Mineralogy and fluid inclusion study of the molybdenum-uranium-fluorite deposit, Gebel Gattar area, Eastern Desert, Egypt. |
| Zoheir, B., McAleer, R., Steele-MacInnis, M., Zeh, A., Bain, W., & Poulette, S. (2022). Vein-type gold formation during late extensional collapse of the Eastern Desert, Egypt: the Gidami deposit. Mineralium Deposita, 1-26. Zoheir, B., Deshesh, F., Broman, C., Pitcairn, I., El-Metwally, A., & Mashaal, S. (2018). Granitoid-associated gold mineralization in Egypt: a case study from the Atalla mine. Mineralium Deposita, 53(5), 701-720. El Monsef, M. A., Slobodník, M., & Salem, I. A. (2018). Hydrothermal evolution of granitoid-hosted gold mineralization in gidami area: An example for orogenic-gold deposits in Egypt. Journal of African Earth Sciences, 146, 132-149. |
| Zoheir, B., Deshesh, F., Broman, C., Pitcairn, I., El-Metwally, A., & Mashaal, S. (2018). Granitoid-associated gold mineralization in Egypt: a case study from the Atalla mine. Mineralium Deposita, 53(5), 701-720. Helmy, H. M., & Kaindl, R. (1999). Mineralogy and fluid inclusion studies of the Au-Cu quartz veins in the Hamash area, South-Eastern Desert, Egypt. Mineralogy and Petrology, 65(1-2), 69-86. Hilmy, M. E., & Osman, A. (1989). Remobilization of gold from a chalcopyrite-pyrite mineralization Hamash gold mine, Southeastern Desert, Egypt. Mineralium Deposita, 24(4), 244-249. |
| Zoheir, B., Deshesh, F., Broman, C., Pitcairn, I., El-Metwally, A., & Mashaal, S. (2018). Granitoid-associated gold mineralization in Egypt: a case study from the Atalla mine. Mineralium Deposita, 53(5), 701-720. |
| Ibrahim, I.M. (2012): Hydrothermal wall rock alteration at Kurdeman gold mine area, Eastern Desert, Egypt. Neues Jahrbuch für Mineralogie - Abhandlungen, 189, 75-95. El-Makky, A.M. Khalil, K.I. |
| Helba, H. A., Khalil, K. I., Mo'nes, M. M., & Khalek, I. A. A. (2020). Zonation in primary geochemical haloes for orogenic vein-type gold mineralization in the Quartz Ridge prospect, Sukari gold mine area, Eastern Desert of Egypt. Journal of Geochemical Exploration, 209, 106378. |
| Helmy, H. M., Kaindl, R., Fritz, H., & Loizenbauer, J. (2004). The Sukari Gold Mine, Eastern Desert—Egypt: structural setting, mineralogy and fluid inclusion study. Mineralium Deposita, 39(4), 495-511. |
| Soliman, M. M. (1984). Ore element distribution in the Mueilha tin mine area, Southeastern Desert, Egypt. J Univ Kuwat (Sci), 11, 97-112. |
| Gehad M. Saleh (2007) Rare-Metal Pegmatites from the Southeastern Desert, Egypt: Geology, Geochemistry, and Petrogenesis. International Geology Review Vol. 49:824-843. |
| Basem A. Zoheir (2012) Controls on lode gold mineralization, Romite deposit, South Eastern Desert, Egypt. Geoscience Frontiers 3:571-585 |
| Zoheir, B., Steele-MacInnis, M., & Garbe-Schönberg, D. (2018). Orogenic gold formation in an evolving, decompressing hydrothermal system: Genesis of the Samut gold deposit, Eastern Desert, Egypt. Ore Geology Reviews. |
| Atef, Abdallah, Surour, Adel A., Madani, Ahmed A., Azer, Mokhles K. (2023) Au-Cu Resources in Some Mines from Antiquity in the South Gabal Um Monqul and Gabal Al Kharaza Prospects, North Eastern Desert, Egypt. Geosciences, 13 (9) doi:10.3390/geosciences13090283 |
| Abed, Neveen S., Mohamed G. El Feky, Atef El-Taher, Ehab El Sayed Massoud, Mahmoud R. Khattab, Mohammed S. Alqahtani, El Sayed Yousef, and Mohamed Y. Hanfi. (2022) "Geochemical Conditions and Factors Controlling the Distribution of Major, Trace, and Rare Elements in Sul Hamed Granitic Rocks, Southeastern Desert, Egypt" Minerals 12, no. 10: 1245. https://doi.org/10.3390/min12101245 |
| El Monsef, M. A., Salem, I., Slobodník, M., & Ragab, A. (2018). Fluid evolution of Au-Cu zones in Um Balad area, North Eastern Desert of Egypt: Implications from mineral chemistry and fluid inclusions. Journal of African Earth Sciences, 143, 321-338. |
| B. A. Zoheir, A. K. El-Shazly, H. Helba, K. I. Khalil and R. J. Bodnar (2008) Origin and evolution of the Um Egat and Dungash orogenic gold deposits, Egyptian Eastern Desert evidence from fluid inclusions in quartz. Economic Geology and the Bulletin of the Society of Economic Geologists 103:405-424 |
| Zoheir, B., Deshesh, F., Broman, C., Pitcairn, I., El-Metwally, A., & Mashaal, S. (2018). Granitoid-associated gold mineralization in Egypt: a case study from the Atalla mine. Mineralium Deposita, 53(5), 701-720. A. El-Taher, K.-L. Kratz, A. Nossair, A.H. Azzam (2003) Determination of gold in two Egyptian gold ores using instrumental neutron activation analysis. Radiation Physics and Chemistry 68:751–755 |
| Faisal, M., Yang, X., Zhang, H., Amuda, A. K., Sun, C., Mustafa, S., & Gul, M. A. (2021). Mineralization styles, alteration mineralogy, and sulfur isotope geochemistry of volcanogenic massive sulfide deposits in the Shadli Metavolcanics Belt, South Eastern Desert, Egypt: Metallogenic implications. Ore Geology Reviews, 104402. |
| Zoheir, Basem, Lohmeier, Stephanie, Tang, Yongyong, Martin, Andrew (2024) Geochemical and geochronological studies of the Um Samiuki deposit (Eastern Desert, Egypt): Metal mobilization in a stratabound massive sulfide ore. Ore Geology Reviews, 166. 105967 doi:10.1016/j.oregeorev.2024.105967 |
| Faisal, M., Yang, X., Zhang, H., Amuda, A. K., Sun, C., Mustafa, S., & Gul, M. A. (2021). Mineralization styles, alteration mineralogy, and sulfur isotope geochemistry of volcanogenic massive sulfide deposits in the Shadli Metavolcanics Belt, South Eastern Desert, Egypt: Metallogenic implications. Ore Geology Reviews, 104402. |
| Faisal, M., Yang, X., Zhang, H., Amuda, A. K., Sun, C., Mustafa, S., & Gul, M. A. (2021). Mineralization styles, alteration mineralogy, and sulfur isotope geochemistry of volcanogenic massive sulfide deposits in the Shadli Metavolcanics Belt, South Eastern Desert, Egypt: Metallogenic implications. Ore Geology Reviews, 104402. |
| Zoheir, Basem, Lohmeier, Stephanie, Tang, Yongyong, Martin, Andrew (2024) Geochemical and geochronological studies of the Um Samiuki deposit (Eastern Desert, Egypt): Metal mobilization in a stratabound massive sulfide ore. Ore Geology Reviews, 166. 105967 doi:10.1016/j.oregeorev.2024.105967 Canadian Mineralogist Feb. 1999 Mineralium Deposita Volume 39, Numbers 5-6, 608-621 |
| El Aref, M., Abd El-Rahman, Y., Zoheir, B., Surour, A., Helmy, H. M., Abdelnasser, A., ... & Ibrahim, M. E. A. (2020). Mineral Resources in Egypt (I): Metallic Ores. In The Geology of Egypt (pp. 521-587). Springer, Cham. Ismail, A. M. (2017). Um Samra-Um Bakra Shear Zone, Central Eastern Desert, Egypt: example of vein-type base metal mineralization. International Journal of Mining Science (IJMS) 3(2):9-25 |
| Gaafar, Ibrahim, Mona Elbarbary, M. I. Sayyed, Abdelmoneim Sulieman, Nissren Tamam, Mayeen U. Khandaker, David A. Bradley, and Mohamed. Y. Hanfi. (2022) "Assessment of Radioactive Materials in Albite Granites from Abu Rusheid and Um Naggat, Central Eastern Desert, Egypt" Minerals 12, no. 2: 120. https://doi.org/10.3390/min12020120 Fawzy, M. M., Kamar, M. S., & Saleh, G. M. (2021). Physical processing for polymetallic mineralization of Abu Rusheid mylonitic rocks, South Eastern Desert of Egypt. International Review of Applied Sciences and Engineering, 12(2), 134-146. Yehia H. Dawood (2011) Mineral Chemistry and Genesis of Uranyl Minerals Associated with Psammitic Gneisses, Abu Rusheid Area, South Eastern Desert of Egypt. JKAU: Earth Sci., Vol. 21, No. 1, pp: 137-169 |
| Zoheir, B. A. (2008). Structural controls, temperature–pressure conditions and fluid evolution of orogenic gold mineralisation at the Betam mine, south Eastern Desert, Egypt. Mineralium Deposita, 43(1), 79-95. |
| Emam, A. (2015) Geochemical Zonal Distribution Of Gold And Associating Elements At Site (S. Ii), Marahiq Gold Mineralization, Wadi Allaqi District, Southern Eastern Desert, Egypt. International Journal of Innovative Science, Engineering & Technology, Vol. 2 Issue 4, April 2015 pp 817-834 |
| Zoheir, B.A. (2008) Characteristics and genesis of shear zone-related gold mineralization in Egypt: A case study from the Um El Tuyor mine, south Eastern Desert. Ore Geology Reviews 34:3, 445-470. Zoheir, B.A. (2004) Gold mineralization in the Um El Tuyor area, South Eastern Desert, Egypt: geologic context, characteristics and genesis. PhD thesis, University of Munich. Unpublished, 159 pages. |
| Zoheir, B., Emam, A., Pitcairn, I. K., Boskabadi, A., Lehaye, Y., & Cooper, M. J. (2018). Trace elements and isotope data of the Um Garayat gold deposit, Wadi Allaqi district, Egypt. Mineralium Deposita, 1-16. www.egsma.gov.eg (n.d.) http://www.egsma.gov.eg/GoldGarayat.htm |
| Helmy, H. M., Stumpfl, E. F., & Kamel, O. A. (1995). Platinum-group minerals from the metamorphosed Abu Swayel Cu-Ni-PGE deposit, South Eastern Desert, Egypt. Economic Geology and the Bulletin of the Society of Economic Geologists, 90(8), 2350-2360. |
| Zoheir, B., & Emam, A. (2014). Field and ASTER imagery data for the setting of gold mineralization in Western Allaqi–Heiani belt, Egypt: A case study from the Haimur deposit. Journal of African Earth Sciences, 99, 150-164. |
| El-Desoky, H. M., & Hafez, H. M. (2018) Petrology, Geochemistry and Mineralogy of the Hydrothermally Altered Rock Units at Wadi Dara, North Eastern Desert, Egypt. Annals Geol. Surv. Egypt. V. XXXV pp. 103 – 140 |
| Kamar, M. (2020) New Occurrence of Gold Mineralization at the Eastern Part of Wadi El Gemal, South Eastern Desert, Egypt. Open Journal of Geology, 10, 1210-1233. doi: 10.4236/ojg.2020.1012060. |
| Zoheir, B. (2011). Transpressional zones in ophiolitic mélange terranes: potential exploration targets for gold in the South Eastern Desert, Egypt. Journal of Geochemical Exploration, 111(1), 23-38. |
| Hussein, H. A., & Bakhit, F. S. (1988). Uranium-Bearing Alkaline Volcanics of North Wadi Kariem and Surroundings, Central Eastern Desert, Egypt. Mining Geology, 38(207), 39-48. |
| Ibrahim, M. E., Saleh, G. M., Dawood, N. A., & Aly, G. M. (2013). Ocellar lamprophyre dyke bearing mineralization, Wadi Nugrus, Eastern Desert, Egypt: Geology, mineralogy and geochemical implications. Journal of Geology and Mining Research, 2(4), 74-86. |
| Kamar, M. S., El Tohamy, A. M., Mira, H. I., & Ismail, A. M. (2022, August). Geology and Environmental Impact Assessment of Psammitic Gneiss and Lamprophyre Dykes at Wadi Sikait, South Eastern Desert, Egypt. In Journal of Physics: Conference Series (Vol. 2305, No. 1, p. 012001). IOP Publishing. Ibrahim, M. A. (2014). Uranium and REEs resources in South Eastern desert of Egypt (No. IAEA-TECDOC-CD--1739). |
| Bisher, A. H. (2012). Primary uranium mineralization in paleochannels of the Um Bogma formation at Allouga Southwestern Sinai. Eleventh Arab Conference on the Peaceful Uses of Atomic Energy. Khartoum. Sudan. 16-20 December 2012 |
| International Geological Congress (2008) MRD-02 Large skarn-type mineralization connected to late to post tectonic Precambrian granitoid intrusions in southeast Sinai, Egypt |
| International Geological Congress (2008) MRD-02 Large skarn-type mineralization connected to late to post tectonic Precambrian granitoid intrusions in southeast Sinai, Egypt |
| International Geological Congress (2008) MRD-02 Large skarn-type mineralization connected to late to post tectonic Precambrian granitoid intrusions in southeast Sinai, Egypt |
| International Geological Congress (2008) MRD-02 Large skarn-type mineralization connected to late to post tectonic Precambrian granitoid intrusions in southeast Sinai, Egypt |
| Helmy, H. M., Morad, A. E., & Rahman, H. B. A. (2021). Um Zariq formation, southeast sinai, Egypt: A new record of the Sturtian Snowball Earth event in the Arabian Nubian Shield. Journal of African Earth Sciences, 173, 104048. |
| International Geological Congress (2008) MRD-02 Large skarn-type mineralization connected to late to post tectonic Precambrian granitoid intrusions in southeast Sinai, Egypt |
| International Geological Congress (2008) MRD-02 Large skarn-type mineralization connected to late to post tectonic Precambrian granitoid intrusions in southeast Sinai, Egypt |
| Afify, A. M., Osman, R. A., Wanas, H. A., & Khater, T. M. (2022). Mineralogical and geochemical studies of copper mineralization in the Paleozoic sedimentary section in southwestern Sinai, Egypt. Ore Geology Reviews, 147, 104994. |
| Afify, A. M., Osman, R. A., Wanas, H. A., & Khater, T. M. (2022). Mineralogical and geochemical studies of copper mineralization in the Paleozoic sedimentary section in southwestern Sinai, Egypt. Ore Geology Reviews, 147, 104994. |
| Ibrahim H. Khalifa, Ahmed M. Hegazi, Mohamed Faisal (2016): Geological setting for porphyry copper deposits in calc-alkaline rocks: Wadi Rofaiyed area, Sinai, Egypt. Arabian Journal of Geosciences 9, 336. |
| Ron Bogoch, Ludwig Halicz and Ya'acov Nathan (1982): Breunnerite from the Tarr albitite complex, Sinai. American Mineralogist, 67, 822-825. |
White Desert, Farafra Oasis, New Valley Governorate, Egypt