A sheared Ophiolitic Mélange: Occurrence, Petrographical And Geochemical Studies, Around Wadi Fatira, North Eastern Desert, Egypt. | ||||
| Sohag Journal of Sciences | ||||
| Volume 7, Issue 2, May 2022, Page 89-96 PDF (997.28 K) | ||||
| Document Type: Regular Articles | ||||
| DOI: 10.21608/sjsci.2022.234256 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
R. Kh. Bekir; A. A. El sheikh; E. A Saber; O. R. Shalaby 
| ||||
| Department of Geology, Faculty of Science, Sohag University, Egypt. | ||||
| Abstract | ||||
| The present study provides a new perspective on the nature and deformational development of the basement rocks in the Fatira area. The goal of the project is to characterise the mélange rocks in the area from a petrographic and geochemical standpoint. Field, petrographic and geochemical studies of the Neoproterozoic rocks in the Wadi Fatira area indicate that these rocks are sheared part of an ophiolitic suite. These rocks comprise serpentinites and their related rocks of talc carbonates and quartz carbonates, sheeted metadolerite, and pillowed metabasalts. The original ophiolitic suite has been deformed and suffered different degrees of shearing, leading to the formation of an ophiolitic mélange that is composed of fragments of the ophiolitic rocks set in a highly sheared mylonitized matrix. The geochemical data revealed that ophiolitic metavolcanics and their mylonites are mainly of basaltic and basaltic andesite composition. They are tholeiitic in nature and originated in an oceanic floor setting. These rocks were mylonitized by the effect of a NE–SW trending dextral shear zone in Wadi Fatira that may represent the second-order shear of the Najd fault system (NFS). | ||||
| Keywords | ||||
| Wadi Fatira; Ophiolitic mélange; mylonite; ultramylonite | ||||
| References | ||||
|
[1] Sabet, A. H.; On the stratigraphy of the basement rocks of Egypt. Annals Geol. Surv. Egypt, 1972, 2, 79-102
[2] Katta, L. A. S.; Zalata, A. A.; Makroum, F. M.; Hadarabiya metavolcanic association, Northern Eastern Desert, Egypt. Bull. Faculty of Science, Mansoura University, 1998, 25(2), 19-54.
[3] Asran, A. M.; Ibrahim, M. A.; El Mansi, M. M.; Abdel Ghani, I. M.; Back-Arc To Active Continental Margin Pan-African Volcanicity Along Wadi Fatirah, Central Eastern Desert, Egypt; Petrological And Geochemical Investigations. Journal of Sebha University-(Pure and Applied Sciences)- 2008, Vol.7 No.2
[4] Khalaf, E. A.; Stratigraphy, facies architecture, and palaeoenvironment of Neoproterozoic volcanics and volcaniclastic deposits in Fatira area, Central Eastern Desert, Egypt. Journal of African Earth Sciences, 2010, 58, 405–426.
[5] Abu El-Leil, I. A.; Bekhit, M. H.; Tolba, A. S.; Moharem, A. F.; Shahin, T. M.; Geological, structural and petrotectonical aspectable features of Neoproterozoic rocks, Gabal El Dob area, north Eastern Desert, Egypt. International Journal of Scientific Engineering and Applied Science (IJSEAS), 2015, 1(8), 332-350.
[6] Abd El Monsef, M.; Slobodník, M.; Salem, I. A.; Characteristics and nature of gold bearing fluids in Fatira area, North Eastern Desert of Egypt, possible transition from intrusion related to orogenic deposits. Arabian Journal of Geosciences, 2020, 13(19), 1-24.
[7] Abdel Ghani, I. M. M.; Geology, Petrology and Radioactivity of Gabal El-Urf Area, Central Eastern Desert, Egypt. Ph.D. thesis, Faculty of Science Sohag University, 2000, 243 pp.
[8] Ineson, P. R.; Introduction to practical ore microscopy. Routledge., 1989, 121 pp.
[9] Cox, K. G.; Bell, J. D.; Pankhurst, R. J.; The interpretation of igneous rocks. George, Allen and Unwin, London, 1979.
[10] Le Bas, M. J.; Le Maitre, R. W.; Streckeisen, A.; Zanettin, B.; A chemical classification of volcanic rocks based on the total alkali silica diagram. Journal of Petrology, 1986, 27, 745 750.
[11] Miyashiro, A.; Volcanic rock series in island arcs and active continental margins. American journal of science, 1974, 274(4), 321-355.
[12] Jensen, L. S.; A new plot for classifying subalkalic volcanic rocks. Ontario Division of Mines, Miscellaneous Paper, 1976, 66, 1-22.
[13] Pearce, J. A.; Cann, J. R.; Tectonic setting of basic volcanic rocks determined using trace element analyses. Earth and planetary science letters, 1973, 19(2), 290-300.
[14] Shervais, J.W.; Ti V plots and the petrogenesis of modern and ophiolitic lavas. Earth and Planetary Science Letters, 1982, 59, 101 118.
[15] Pearce, J. A.; Norry, M. J.; Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks. Contributions to mineralogy and petrology, 1979, 69(1), 33-47.
[16] Greiling, R. O.; Directions of Pan African thrusting in the Eastern Desert of Egypt derived from lineation and strain data. In Colloquium on african geology. 1987, 14, 83-86.
[17] Greiling, R. O.; Rashwan, A. A.; El Ramly, M. F.; El Din, G. K.; Towards a comprehensive structural synthesis of the (Proterozoic) Arabian-Nubian Shield in E. Egypt. In Geoscientific Research in Northeast Africa, Balkema Rotterdam, 1993, 15-19.
[18] Greiling, R. O.; Abdeen, M. M.; Dardir, A. A.; El Akhal, H.; El Ramly, M. F.; Kamal, G. E. D. et al.; A structural synthesis of the Proterozoic Arabian-Nubian Shield in Egypt. Geologische Rundschau, 1994, 83(3), 484-501.
[19] Abdelsalam, M. G.; Stern, R. J.; Sutures and shear zones in the Arabian-Nubian Shield. Journal of African Earth Sciences, 1996, 23(3), 289-310.
[20] Elbashbeshy, E. M. A.; Emam, T. G.; Abdel-Wahed, M. S.; Flow and heat transfer over a moving surface with nonlinear velocity and variable thickness in a nanofluid in the presence of thermal radiation. Canadian journal of Physics, 2014, 92(2), 124-130.
[21] Williams, H.; Turner, F. J.; Gilbert, C. M.; Petrography: An introduction to the study of rocks in thin section, 1982, 504-505.
[22] Prinz, M.; Poldervaart, A.; Layered mylonite from Beartooth mountains, Montana. Geological Society of America Bulletin, 1964, 75(8), 741-744.
[23] Abd El- Wahed, M. A.; Abu Anbar, M. M.; Synoblique convergent and extensional deformation and metamorphism in the Neoproterozoic rocks along Wadi Fatira shear zone, Northern Eastern Desert, Egypt. Arabian Journal of Geosciences, 2009, 2, 29-52.
[24] Abdelsalam, M. G.; Abdeen, M. M.; Dowaidar, H. M.; Stern, R. J.; Abdelghaffar, A. A.; Structural evolution of the Neoproterozoic western Allaqi–Heiani suture, southeastern Egypt. Precambrian Research, 2003, 124(1), 87-104.
[25] Stern, R. J.; Kröner, A.; Manton, W. I.; Reischmann, T.; Mansour, M.; Hussein, I. M.; Geochronology of the late Precambrian Hamisana shear zone, Red sea Hills, Sudan and Egypt. Journal of the Geological Society, 1989, 146(6), 1017-1029.
[26] De Wall, H.; Greiling, R. O.; Sadek, M. F.; Post-collisional shortening in the late Pan-African Hamisana high strain zone, SE Egypt: field and magnetic fabric evidence. Precambrian Research, 2001, 107(3-4), 179-194. | ||||
|
Statistics Article View: 309 PDF Download: 168 |
||||
