Gold endowment in the evolution of the Allaqi-Heiani suture, Egypt: A synthesis of geological, structural, and space-borne imagery data

Abstract Field and structural studies supported by multi-sensor satellite-based imagery data are attempted to decipher the setting and controls of gold-bearing quartz veins in the central part of the greater Wadi Allaqi district in the South Eastern Desert of Egypt. Here, we assess the evolution of a complex part of the Neoproterozoic Allaqi-Heiani suture (∼730–700 Ma) with ample structures demonstrating the final Gondwanan collision. Abundant extensive N-trending folds, sinistral shear zones and oblate fold patterns and strain fabrics exemplifying an oblique convergence and torsion related to a regional ∼E-W compressional regime. In the Wadi Seiga area, the first order upright and overturned folds and thrusts (D1 structures) are mostly obliterated by intense NW-ward transpression, N-ward folding and transcurrent shearing assigned to as D2 and D3 structures. The domal crescentic and mushroom superimposed fold patterns suggest that Type 2 and Type 3 fold interference patterns were synchronous at some time during D2 or D3. Shear zones with abundant signs of plastic deformation and associated with quartz veins, within the axial planes of NNW- and NNE-trending F3 folds may imply gold mineralization during the third deformation stage (D3). The latter was supplemented or terminated by an episode of northward tectonic escape and slip reactivation of the pre-existing NW-trending faults. Integrated with field measurements, satellite-based radar and radiometer data abetted untangling the superimposed structures. Gold occurrences in the area are confined to domains of superimposed foliations, foliation deflection/steepening, foliation refraction and substantial strain partitioning, or at oppositely interfered plunging folds. The scattered small scale occurrences of ≤10 s g/t Au-bearing gold-quartz veins in such high strain zones, together with the lack of spatial association with a particular intrusive phase weigh with the metamorphic model for gold-only endowment in the area. The peak metamorphic conditions (amphibolite facies) in the central Allaqi-Heiani suture were attained not earlier than 630 Ma, during the collision of the Arabian-Nubian Shield with the Nile Craton to the west (provoked at 670–610 Ma). Gold-only endowment was complementing to the latest stages of deformation and terrane cooling between 610 and 585 Ma. Listvenitization of tectonized ophiolites and widespread sericite alteration of the island arc metavolcaniclastic rocks could have been promoted by the late-orogenic felsic intrusions (∼603 Ma) that filled oblate dilation spaces developed by structural transport to the north. The late orogenic timing of mineralization is one of many features making the Allaqi-Heiani suture comparable to well-documented global examples of accretionary metallogenic belts.

[1]  B. Zoheir,et al.  The tectono-metamorphic evolution of the central part of the Neoproterozoic Allaqi–Heiani suture, south Eastern Desert of Egypt , 2007 .

[2]  M. Abdelsalam,et al.  Zircon U–Pb ages, δ18O and whole-rock Nd isotopic compositions of the Dire Dawa Precambrian basement, eastern Ethiopia: implications for the assembly of Gondwana , 2016, Journal of the Geological Society.

[3]  M. Hashim,et al.  Application of Landsat-8 and ALOS-2 data for structural and landslide hazard mapping in Kelantan, Malaysia , 2017 .

[4]  Saygin Abdikan,et al.  A comparative data-fusion analysis of multi-sensor satellite images , 2014, Int. J. Digit. Earth.

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

[6]  Peter A. Cawood,et al.  Metallogeny of accretionary orogens - The connection between lithospheric processes and metal endowment , 2009 .

[7]  D. Groves,et al.  Geodynamic settings of mineral deposit systems , 2007, Journal of the Geological Society.

[8]  A. El-Battay,et al.  PALSAR-FBS L-HH Mode and Landsat-TM Data Fusion for Geological Mapping , 2016 .

[9]  Basem Zoheir,et al.  Characteristics and genesis of shear zone-related gold mineralization in Egypt: A case study from the Um El Tuyor mine, south Eastern Desert , 2008 .

[10]  M. Abdeen,et al.  Syn- and post-accretionary structures in the Neoproterozoic Central Allaqi-Heiani suture zone, Southeastern Egypt , 2011 .

[11]  R. Stern.  Tectonic evolution of the Late Proterozoic East African Orogen: Constraints from crustal evolution in the Arabian-Nubian Shield and the Mozambique Belt , 2017 .

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

[13]  T. Dixon,et al.  Late Proterozoic evolution of the northern part of the Hamisana zone, northeast Sudan: constraints on Pan-African accretionary tectonics , 1992, Journal of the Geological Society.

[14]  Jun Ma,et al.  Estimating aboveground biomass of broadleaf, needleleaf, and mixed forests in Northeastern China through analysis of 25-m ALOS/PALSAR mosaic data , 2017 .

[15]  W. Frisch,et al.  Origin of the Wadi Haimur–Abu Swayel gneiss belt, south Eastern Desert, Egypt: petrological and geochronological constraints , 2002 .

[16]  D. Groves,et al.  100th Anniversary Special Paper: Secular Changes in Global Tectonic Processes and Their Influence on the Temporal Distribution of Gold-Bearing Mineral Deposits , 2005 .

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

[18]  El Kazzaz,et al.  Tectonics and mineralization of Wadi Allaqi, south Eastern Desert, Egypt , 1995 .

[19]  S. Kamh,et al.  Tectonics of the Eastern Desert of Egypt: Key to Understanding the Neoproterozoic Evolution of the Arabian–Nubian Shield (East African Orogen) , 2018, The Geology of the Arab World---An Overview.

[20]  C. Hodgson.  Mesothermal lode-gold deposits , 1993 .

[21]  B. Windley,et al.  Mega-fold interference patterns in the Beishan orogen (NW China) created by change in plate configuration during Permo-Triassic termination of the Altaids , 2013 .

[22]  S. Wilde,et al.  Age constraints on the formation and emplacement of Neoproterozoic ophiolites along the Allaqi–Heiani Suture, South Eastern Desert of Egypt , 2010 .

[23]  R. Thomas,et al.  Himalayan-type indenter-escape tectonics model for the southern part of the late Neoproterozoic–early Paleozoic East African– Antarctic orogen , 2004 .

[24]  Said A. El-Nisr.  Late precambrian volcanism at Wadi Allaqi, south Eastern Desert, Egypt: evidence for transitional continental arc/margin environment , 1997 .

[25]  Jie Yang,et al.  Adaptive-Window Polarimetric SAR Image Speckle Filtering Based on a Homogeneity Measurement , 2015, IEEE Transactions on Geoscience and Remote Sensing.

[26]  R. Shackleton.  Review of Late Proterozoic sutures, ophiolitic mélanges and tectonics of eastern Egypt and north-east Sudan , 1994 .

[27]  D. Groves,et al.  The characteristics, origins, and geodynamic settings of supergiant gold metallogenic provinces , 2000 .

[28]  A. Kröner,et al.  Dating of late Proterozoic ophiolites in Egypt and the Sudan using the single grain zircon evaporation technique , 1992 .

[29]  M. Hashim,et al.  Structural Mapping of the Bentong‐Raub Suture Zone Using PALSAR Remote Sensing Data, Peninsular Malaysia: Implications for Sediment‐hosted/Orogenic Gold Mineral Systems Exploration , 2016 .

[30]  W. Manton,et al.  SHRIMP zircon dating and Sm/Nd isotopic investigations of Neoproterozoic granitoids, Eastern Desert, Egypt , 2008 .

[31]  D. Groves,et al.  Structural geometry of orogenic gold deposits: Implications for exploration of world-class and giant deposits , 2018, Geoscience Frontiers.

[32]  B. Zoheir.  Controls on lode gold mineralization, Romite deposit, South Eastern Desert, Egypt , 2012 .

[33]  J. G. Richard,et al.  Metallogenic provinces in an evolving geodynamic framework , 2005 .

[34]  M. Hashim,et al.  Integrating PALSAR and ASTER data for mineral deposits exploration in tropical environments: a case study from Central Belt, Peninsular Malaysia , 2015 .

[35]  B. Zoheir.  Lode-gold mineralization in convergent wrench structures: Examples from South Eastern Desert, Egypt , 2012 .

[36]  M. Abdelsalam.  The Oko Shear Zone, Sudan: post-accretionary deformation in the Arabian-Nubian Shield , 1994, Journal of the Geological Society.

[37]  R. Greiling,et al.  Post-collisional shortening in the late Pan-African Hamisana high strain zone, SE Egypt: field and magnetic fabric evidence , 2001 .

[38]  B. Zoheir,et al.  Trace elements and isotope data of the Um Garayat gold deposit, Wadi Allaqi district, Egypt , 2018, Mineralium Deposita.

[39]  Basem Zoheir,et al.  Origin and Evolution of the Um Egat and Dungash Orogenic Gold Deposits, Egyptian Eastern Desert: Evidence from Fluid Inclusions in Quartz , 2008 .

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

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

[42]  Dianwei Ren,et al.  Tracing along-strike structural continuity in the Neoproterozoic Allaqi-Heiani Suture, southern Egypt using principal component analysis (PCA), fast Fourier transform (FFT), and redundant wavelet transform (RWT) of ASTER data , 2006 .

[43]  James S. Cleverley,et al.  The role of metamorphic fluids in the formation of ore deposits , 2013 .

[44]  B. Zoheir,et al.  Geochemistry and mineral chemistry of lode gold mineralisation, SE Egypt: implications for ore genesis and exploration , 2013, Arabian Journal of Geosciences.

[45]  F. Finger,et al.  Composition and total-Pb model ages of monazite from high-grade paragneisses in the Abu Swayel area, southern eastern desert, Egypt , 1998 .

[46]  P. Johnson,et al.  Development of the Arabian-Nubian Shield: perspectives on accretion and deformation in the northern East African Orogen and the assembly of Gondwana , 2003, Geological Society, London, Special Publications.

[47]  Basem Zoheir,et al.  Transpressional zones in ophiolitic mélange terranes: Potential exploration targets for gold in the South Eastern Desert, Egypt , 2011 .

[48]  Dietrich D. Klemm,et al.  Gold and gold mining in ancient Egypt and Nubia : geoarchaeology of the ancient gold mining sites in the Egyptian and Sudanese eastern desert , 2013 .

[49]  P. Johnson,et al.  Continental lithosphere of the Arabian Plate: A geologic, petrologic, and geophysical synthesis , 2010 .

[50]  Mazlan Hashim,et al.  Structural geology mapping using PALSAR data in the Bau gold mining district, Sarawak, Malaysia , 2014 .

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

[52]  P. Townsend.  Principles and Applications of Imaging Radar: Manual of Remote Sensing , 2000 .

[53]  W. Taylor,et al.  Tectonic evolution of the Allaqi shear zone and implications for Pan-African terrane amalgamation in the south Eastern Desert, Egypt , 2001 .

[54]  Richard J. Goldfarb,et al.  Phanerozoic continental growth and gold metallogeny of Asia , 2014 .

[55]  Basem Zoheir,et al.  Structural controls, temperature–pressure conditions and fluid evolution of orogenic gold mineralisation at the Betam mine, south Eastern Desert, Egypt , 2008 .

[56]  Rajat Gupta,et al.  Remote Sensing Geology , 1991 .

[57]  E. Draganits,et al.  Classification of Refold Structures , 2004, The Journal of Geology.

[58]  Basem Zoheir,et al.  Auriferous shear zones in the central Allaqi-Heiani belt: Orogenic gold in post-accretionary structures, SE Egypt , 2017, Journal of African Earth Sciences.

[59]  A. R. Harrison,et al.  Standardized principal components , 1985 .

[60]  Timothy M. Kusky,et al.  Structural controls on Neoproterozoic mineralization in the South Eastern Desert, Egypt: an integrated field, Landsat TM, and SIR-C/X SAR approach , 2002 .

[61]  R. Goldfarb,et al.  Secular Variation in Economic Geology , 2010 .

[62]  B. Zoheir,et al.  Au and Cr mobilization through metasomatism: Microchemical evidence from ore-bearing listvenite, South Eastern Desert of Egypt , 2013 .

[63]  M. Darwish.  Geochemical and Environmental Evaluation of Um Shashoba Gold Mine Area, Southeastern Desert, Egypt , 2011 .

[64]  R. Shackleton.  The final collision zone between East and West Gondwana: where is it? , 1996 .

[65]  H. Frimmel.  Episodic concentration of gold to ore grade through Earth's history , 2018 .

[66]  John F. Mustard,et al.  Detection and discrimination of sulfate minerals using reflectance spectroscopy , 2006 .

[67]  W. Frisch,et al.  Evolution of the Pan‐African Wadi Haimur metamorphic sole, Eastern Desert, Egypt , 2000 .

[68]  A. Emam,et al.  Comprehensive Mapping of the Island Arc Rocks in the Marahiq Area, South Eastern Desert, Egypt , 2014 .