Shear-Related Gold Ores in the Wadi Hodein Shear Belt, South Eastern Desert of Egypt: Analysis of Remote Sensing, Field and Structural Data

Abstract

Space-borne multispectral and radar data were used to comprehensively map geological contacts, lithologies and structural elements controlling gold-bearing quartz veins in the Wadi Hodein area in Egypt. In this study, enhancement algorithms, band combinations, band math (BM), Principal Component Analysis (PCA), decorrelation stretch and mineralogical indices were applied to Landsat-8 OLI, ASTER and ALOS PALSAR following a pre-designed flow chart. Together with the field observations, the results of the image processing techniques were exported to the GIS environment and subsequently fused to generate a potentiality map. The Wadi Hodein shear belt is a ductile shear corridor developed in response to non-coaxial convergence and northward escape tectonics that accompanied the final stages of terrane accretion and cratonization (~680–600 Ma) in the northern part of the Arabian–Nubian Shield. The evolution of this shear belt encompassed a protracted ~E–W shortening and recurrent sinistral transpression as manifested by east-dipping thrusts and high-angle reverse shear zones. Gold-mineralized shear zones cut heterogeneously deformed ophiolites and metavolcaniclastic rocks and attenuate in and around granodioritic intrusions. The gold mineralization event was evidently epigenetic in the metamorphic rocks and was likely attributed to rejuvenated tectonism and circulation of hot fluids during transpressional deformation. The superposition of the NW–SE folds by NNW-trending, kilometer scale tight and reclined folds shaped the overall framework of the Wadi Hodein belt. Shallow NNW- or SSE-plunging mineral and stretching lineations on steeply dipping shear planes depict a considerable simple shear component. The results of image processing complying with field observations and structural analysis suggest that the coincidence of shear zones, hydrothermal alteration and crosscutting dikes in the study area could be a considered as a model criterion in exploration for new gold targets.

Integrated NIR-HE based SPOT-5 image enhancement method for features preservation and edge detection

“…3, December 2021: 1499 -1514 1504 value which is nearly equal to the proposed method, specifically 0.4192 for scene one, 0.4478 for scene two, and 0.4612 for scene three. However, the decorrelation stretch (DECORR) results are more suitable for densitybased vegetation analysis, from which it is fit and able to distinguish more than one feature [182]- [194]. On the other hand, the proposed method enhanced the image by distributing its brightness levels together with the whole brightness scale [118], [193].…”

Neoproterozoic Tectonic Events of Egypt

“…19a-c) and transpressional sinistral sense of movement is established by several kinematic indicators such as porphyroclasts (Fig. 19d), mylonitic foliations, deflected markers and S-C structures (Hamimi et al, 2019;Hamimi and Abd El-Wahed, 2020;Abd El-Wahed et al, 2021). The Kharit-Hodein shear zone is regarded as the youngest major structural element in the ENS, formed under a sinistral transpressional corridor (Greiling et al, 1994;Nano et al, 2002), overprinted by a dextral sense of shear (Hamimi et al, 2016).…”

“…Kamal El Din et al, 1992). Oblique convergence transpression, whether dextral or sinistral, is a proposed mechanism adopted by many authors (Fritz et al, 1996;Loizenbauer et al, 2001;Makroum, 2001;Bregar et al, 2002;Shalaby et al, 2005;Abd El-Wahed, 2008, 2010Shalaby, 2010;Kamh, 2010, 2013;Zoheir and Lehmann, 2011;Zoheir and Weihed, 2014;Abd El-Wahed et al, 2016Abd El-Wahed and Thabet, 2017;Makroum, 2017;Hamdy et al, 2017;Stern, 2017;Zoheir et al, 2019;Hamimi et al, 2019;Abd El Monsef, 2020;Abd El-Wahed and Hamimi, 2021a and b;Abd El-Wahed et al, 2021) to explain and imply the deformation styles in the Eastern Desert.…”

Application of Dirichlet Process and Support Vector Machine Techniques for Mapping Alteration Zones Associated with Porphyry Copper Deposit Using ASTER Remote Sensing Imagery

“…Mixed model DP uses a database distribution to model data that are mixed from several clusters. DP is generally formulated using Equation (1), but the number of model parameters is not fixed and can be changed as needed.…”

“…The use of remote sensing data to obtain information from far objects is one of the most significant technologies in this century. Remote sensing satellite imagery is extensively used in different sectors of Earth science such as mineral mapping [1][2][3][4]. The results of remote sensing studies, by means of saving time and cost in identifying alteration zones, have greatly contributed to the exploration of minerals, especially in the reconnaissance stages [5][6][7][8].…”