Pan-African dextral transpressive duplex and flower structure in the Central Eastern Desert of Egypt

Abstract The NE–SW trending Mubarak shear belt in the Central Eastern Desert (CED) of Egypt records the structural features of a transpression regime. Structural interpretation of satellite data and field observations indicates the presence of two episodes of deformation. The less dominant D1 deformation is related to sinistral movement along NW–SE trending Wadi Abu Dabbab shear zone and formation of F1 tight to isoclinal non-cylindrical folds and thrust fan as a consequence of transpression. The thrust fan includes ESE- to SE-dipping thrusts in the ophiolitic melange and S- to SSW-dipping thrusts in the northern part of the metagabbro–diorite complex. The transpression-related sinistral shear regime is superimposed by the dominant D2 dextral transpression along NE–SW trending Wadi El-Umra shear zone. This dextral shearing is characterized by development of NNE- to NE-trending S2 cleavage, strike-slip duplex, NNE- and NE-trending F2 folds, and NNW-directed thrusts. These two events represent a single progressive phase associated with sinistral transpressional deformation, which is related to a younger E–W shortening event. E–W directed shortening is due to oblique convergence between East and West Gondwana along the Mozambique belt. Transpressional structures in the NE–SW trending Mubarak–Barramiya shear belt indicate highly oblique convergence leading to wrench-dominated dextral transpression and development of a major flower structure between Wadi Mubarak and Hafafit dome occupying the whole width of the CED.

[1]  Ali Faghih,et al.  Transpressional deformations within the Sanandaj Sirjan metamorphic belt (Zagros Mountains, Iran) , 2008 .

[2]  V. Prasannakumar,et al.  Fabric evolution in Salem-Attur Shear Zone, South India, and its implications on the kinematics , 2009 .

[3]  H. Fritz,et al.  A late Neoproterozoic magmatic core complex in the Eastern Desert of Egypt: emplacement of granitoids in a wrench-tectonic setting , 2002 .

[4]  H. Fritz,et al.  The Wadi Mubarak belt, Eastern Desert of Egypt: a Neoproterozoic conjugate shear system in the Arabian-Nubian Shield , 2005 .

[5]  T. Fowler,et al.  Gneiss-cored interference dome associated with two phases of late Pan-African thrusting in the Central Eastern Desert, Egypt , 2001 .

[6]  G. Mitra,et al.  A new kinematic evolutionary model for the growth of a duplex — an example from the Rangit duplex, Sikkim Himalaya, India , 2009 .

[7]  P. Johnson,et al.  Oblique sinistral transpression in the Arabian shield: The timing and kinematics of a Neoproterozoic suture zone , 2001 .

[8]  Rushdi Said.  The Geology Of Egypt , 1962 .

[9]  R. Stern.  ARC Assembly and Continental Collision in the Neoproterozoic East African Orogen: Implications for the Consolidation of Gondwanaland , 1994 .

[10]  J. Dewey,et al.  World distribution of sutures — the sites of former oceans , 1977 .

[11]  G. Y. Boghdady,et al.  Structural constraints on the evolution of the Meatiq Gneiss Dome (Egypt), East-African Orogen , 2010 .

[12]  M. Azer,et al.  Supra-subduction affinity in the Neoproterozoic serpentinites in the Eastern Desert, Egypt: Evidence from mineral composition , 2007 .

[13]  D. Gray,et al.  Structure and strain variation at mid-crustal levels in a transpressional orogen: A review of Kaoko Belt structure and the character of West Gondwana amalgamation and dispersal , 2008 .

[14]  R. Kaindl,et al.  Mineralogy and fluid inclusion studies of the Au-Cu quartz veins in the Hamash area, South-Eastern Desert, Egypt , 1999 .

[15]  A. Asran,et al.  The pre-Pan-African deformed granite cycle of the Gabal El-Sibai swell, Eastern Desert, Egypt , 1995 .

[16]  J Loizenbauer,et al.  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 , 2001 .

[17]  H. Harraz.  Fluid inclusions in the mesozonal gold deposit at Atud mine, Eastern Desert, Egypt , 2002 .

[18]  H. Fritz,et al.  Neoproterozoic tectonothermal evolution of the Central Eastern Desert, Egypt: a slow velocity tectonic process of core complex exhumation , 2002 .

[19]  S. Reddy,et al.  High-strain zone deformation in the southern Capricorn Orogen, Western Australia: kinematics and age constraints , 2004 .

[20]  Mohamed A. Abd El-Wahed,et al.  Thrusting and transpressional shearing in the Pan-African nappe southwest El-Sibai core complex, Central Eastern Desert, Egypt , 2008 .

[21]  C. Passchier,et al.  Oblique collision and evolution of large-scale transcurrent shear zones in the Kaoko belt, NW Namibia , 2005 .

[22]  H. Fossen,et al.  Shear zone structures in the Øygarden area, West Norway , 1990 .

[23]  R. Machado,et al.  Shear structures in the Serra do Azeite shear zone, southeastern Brazil: Transtensional deformation during regional transpression in the central Mantiqueira province (Ribeira belt) , 2007 .

[24]  R. Greiling,et al.  A Quantitative structural study of late pan-african compressional deformation in the central eastern desert (Egypt) during Gondwana assembly , 2005 .

[25]  R. Greiling,et al.  A structural synthesis of the Proterozoic Arabian-Nubian Shield in Egypt , 1994 .

[26]  C. Passchier,et al.  Shear-sense indicators: A review , 1991 .

[27]  R. Stern.  The Najd Fault System, Saudi Arabia and Egypt: A Late Precambrian rift‐related transform system? , 1985 .

[28]  Timothy M. Kusky,et al.  Lithological mapping in the Eastern Desert of Egypt, the Barramiya area, using Landsat thematic mapper (TM) , 2006 .

[29]  M. El-Wahed.  The role of the Najd Fault System in the tectonic evolution of the Hammamat molasse sediments, Eastern Desert, Egypt , 2010 .

[30]  J. Moore.  Tectonics of the Najd Transcurrent Fault System, Saudi Arabia , 1979, Journal of the Geological Society.

[31]  A. Fowler,et al.  El Sibai gneissic complex, Central Eastern Desert, Egypt: Folded nappes and syn-kinematic gneissic granitoid sheets – not a core complex , 2007 .

[32]  M. El-Wahed,et al.  Synoblique convergent and extensional deformation and metamorphism in the Neoproterozoic rocks along Wadi Fatira shear zone, Northern Eastern Desert, Egypt , 2009 .

[33]  N. J. Silberling,et al.  Wrangellia-A displaced terrane in northwestern North America , 1977 .

[34]  A. Matin.  Structural anatomy of the Kushtagi schist belt, Dharwar craton, south India—An example of Archaean transpression , 2006 .

[35]  W. B. Harland.  Tectonic transpression in Caledonian Spitsbergen , 1971, Geological Magazine.

[36]  D. Sanderson,et al.  Fault damage zones , 2004 .

[37]  A. Shalaby.  The northern dome of Wadi Hafafit culmination, Eastern Desert, Egypt: Structural setting in tectonic framework of a scissor-like wrench corridor , 2010 .

[38]  Basil Tikoff,et al.  Stretching lineations in transpressional shear zones: an example from the Sierra Nevada Batholith , 1997 .

[39]  S. Peacock,et al.  Kinematic evolution of the Miller Range Shear Zone, Central Transantarctic Mountains, Antarctica, an , 1993 .

[40]  T. Chetty,et al.  The Cauvery Shear Zone, Southern Granulite Terrain, India: A crustal-scale flower structure , 2006 .

[41]  C. Passchier.  The fabric attractor , 1997 .

[42]  A. Ries,et al.  The relation between regionally consistent stretching lineations and plate motions , 1984 .

[43]  Richard R. Jones,et al.  Strain partitioning in transpression zones , 1995 .

[44]  S. Schmid,et al.  An evaluation of criteria to deduce the sense of movement in sheared rocks , 1983 .

[45]  J. Chorowicz,et al.  Northward expulsion of the Pan-African of northeast Africa guided by a reentrant zone of the Tanzania craton , 1992 .

[46]  R. Holdsworth,et al.  Interlinked system of ductile strike slip and thrusting formed by Caledonian sinistral transpression in northeastern Greenland , 1991 .

[47]  C. Passchier,et al.  An outline of shear-sense analysis in high-grade rocks , 2006 .

[48]  R. Greiling,et al.  Thrusting and multiple folding in the Neoproterozoic Pan-African basement of Wadi Hodein area, south Eastern Desert, Egypt , 2008 .

[49]  A. Vauchez,et al.  Ductile duplexing at a bend of a continental-scale strike-slip shear zone: example from NE Brazil , 1996 .

[50]  M. Abdelsalam,et al.  The Saharan metacraton , 2002 .

[51]  K. Khalil,et al.  Genesis of the gold mineralization at the Dungash gold mine area, Eastern Desert, Egypt: a mineralogical microchemical study , 2003 .

[52]  A. Fowler,et al.  The Sha'it-Nugrus shear zone separating Central and South Eastern Deserts, Egypt: A post-arc collision low-angle normal ductile shear zone , 2009 .

[53]  T. Kusky,et al.  Structural and remote sensing analysis of the Betsimisaraka Suture in northeastern Madagascar , 2009 .

[54]  Mohamed A. Abd El-Wahed,et al.  Structural setting of Cretaceous pull-apart basins and Miocene extensional folds in the Quseir–Umm Gheig region, northwestern Red Sea, Egypt , 2010 .

[55]  W. Kurz,et al.  Progressive development of lattice preferred orientations (LPOs) of naturally deformed quartz within a transpressional collision zone (Panafrican Orogen in the Eastern Desert of Egypt) , 2000 .

[56]  K. Jones,et al.  Crustal thickening and ductile extension in the NE Greenland Caledonides: a metamorphic record from anatectic pelites , 2000 .

[57]  A. Vauchez,et al.  The Borborema shear zone system, NE Brazil , 1995 .

[58]  G. Gutiérrez-Alonso,et al.  The North American Cordillera and West European Variscides: Contrasting interpretations of similar mountain systems , 2010 .

[59]  R. Holdsworth,et al.  The anatomy and evolution of a transpressional imbricate zone, Southern Uplands, Scotland , 2004 .

[60]  R. Machado,et al.  Pluton emplacement in a releasing bend in a transpressive regime: the arrozal granite in the Paraíba do Sul shear belt, Rio de Janeiro. , 2007, Anais da Academia Brasileira de Ciencias.

[61]  M. Abdelsalam,et al.  Terrane rotation during the East African Orogeny: Evidence from the Bulbul Shear Zone, south Ethiopia , 2008 .

[62]  A. Fowler,et al.  The significance of gneissic rocks and synmagmatic extensional ductile shear zones of the Barud area for the tectonics of the North Eastern Desert, Egypt , 2006 .

[63]  Robert J. Stern,et al.  Sutures and shear zones in the Arabian-Nubian Shield , 1996 .

[64]  R. Machado,et al.  Transpressive dextral shear in the Italva-Itaperuna section, Northern State of Rio de Janeiro, Brazil. , 2008, Anais da Academia Brasileira de Ciencias.

[65]  C. Teyssier,et al.  Strain modeling of displacement-field partitioning in transpressional orogens , 1994 .

[66]  R. Stern.  Petrogenesis and tectonic setting of late Precambrian ensimatic volcanic rocks, central eastern desert of Egypt , 1981 .

[67]  M. A. Abd El-Wahed,et al.  Wrench structural deformation in Ras Al Hilal-Al Athrun area, NE Libya: a new contribution in Northern Al Jabal Al Akhdar Belt , 2011 .

[68]  H. Fritz,et al.  The Sukari Gold Mine, Eastern Desert—Egypt: structural setting, mineralogy and fluid inclusion study , 2004 .

[69]  F. F. A. El-Ela.  Geochemistry of an island-arc plutonic suite: Wadi Dabr intrusive complex, Eastern Desert, Egypt , 1997 .

[70]  J. Ramsay.  Shear zone geometry: A review , 1980 .

[71]  P. R. Cobbold,et al.  Development of sheath folds in shear regimes , 1980 .

[72]  G. Lister,et al.  S-C Mylonites , 1984 .

[73]  D. Secor,et al.  On resolving shear direction in foliated rocks deformed by simple shear , 1990 .

[74]  R. Greiling,et al.  On the tectonic evolution of the Wadi Hafafit area and environs, eastern desert of Egypt , 1982 .

[75]  H. Fritz,et al.  The El Mayah molasse basin in the Eastern Desert of Egypt , 2006 .

[76]  T. Kusky,et al.  Neoproterozoic nappes and superposed folding of the Itremo Group, west-central Madagascar , 2007 .

[77]  Mamdouh M. Abdeen,et al.  Structural evolution of the Neoproterozoic Western Allaqi–Heiani suture, southeastern Egypt , 2003 .

[78]  R. Stern,et al.  Late Precambrian Crustal Evolution in NE Sudan: Isotopic and Geochronologic Constraints , 1993, The Journal of Geology.

[79]  M. El-Bialy.  On the Pan-African transition of the Arabian-Nubian Shield from compression to extension: The post-collision Dokhan volcanic suite of Kid-Malhak region, Sinai, Egypt , 2010 .

[80]  H. Fritz,et al.  Formation of Neoproterozoic metamorphic complex during oblique convergence (Eastern Desert, Egypt) , 1996 .

[81]  S. Mazumdar,et al.  Deformation mechanisms in the frontal Lesser Himalayan Duplex in Sikkim Himalaya, India , 2009 .

[82]  D. Gray,et al.  Structure of the Kaoko Belt, Namibia: progressive evolution of a classic transpressional orogen , 2003 .

[83]  N. Woodcock,et al.  Transpressive duplex and flower structure: Dent Fault System, NW England , 2003 .