Remote sensing-based mapping of the Wadi Sa’al-Wadi Zaghara basement rocks, southern Sinai, Egypt

Abstract

The Wadi Sa'al-Wadi Zaghara area, southern Sinai, Egypt is a key geologic region within the framework of the Arabian-Nubian Shield (ANS). It almost documents the whole tectono-thermal evolution history of the Pan-African orogeny; hence it records the latest stages of Rodinia breakup (Late Mesoproterozoic) till the penultimate regional deformation event (D3) that impacted the northern tip of the ANS in the Late Neoproterozoic, i.e., before the Najd fault system. Since the metamorphosed volcano-sedimentary rock units in both Wadi Sa’al and Wadi Zaghara exhibit considerable differences in their geological evolution, they were dealt with as two distinct metamorphic belts. They cover a wide spectrum of basement rock varieties, which developed over a long period of time, from Late Mesoproterozoic (Wadi Sa’al metamorphosed volcano-sedimentary rocks) till Late Neoproterozoic Ediacaran period (post-collision granites). The different rock units of the study area were discriminated based on various image processing techniques such as Decorrelation Stretch (DS) Band Ratio (BR) and Principal Component (PC) of Sentinel-2, Landsat-8 and ASTER datasets. Remote sensing data analyses with the aid of petrography, previously published data and field verification enabled us to produce a new enhanced geological map of the study area. Advanced Land Observing Satellite (ALOS) digital elevation and enhanced Sentinel-2, Sobel directional filter images were successfully used for automatic lineaments extraction in the study area.

Keywords

• Landsat-8
• Sentinel-2
• ASTER
• Geologic mapping
• Wadi Sa’al-Zaghara area