Delineation of the subsurface boundary between the Central and Southern Eastern Desert, Egypt

Abstract

The shear zone characterization is a substantial task for understanding the influencing tectonic movements. In this study, an integrated approach of remote sensing and aeromagnetic data is introduced to imagine and trace the subsurface shear zone between the Central (CED) and Southern (SED) domains of the Egyptian Eastern Desert in comparison with the previously proposed approaches mainly using only surface criteria. To produce an enhanced geological map reflecting the different lithological units along both sides of the surficial shear zone, Landsat-8 images are processed and interpreted using False Color Composite (FCC), Color Ratio Composites (CRC). Moreover, the associated lineaments and their trends are extracted from Digital Elevation Model (DEM) data using the lineaments extraction approaches. For delineating the subsurface structures pattern and tracking the probable subsurface CED/SED boundary, aeromagnetic datasets are reduced to magnetic pole (RTP) and, then, interpreted by applying significant techniques comprising upward continuation, Gaussian separation filter, horizontal gradient magnitude (HGM), and tilt derivative angle (TDR). The best path of the shear zone line at depths was imagined; this path agrees with some geologists' opinion regarding the superficial description of the CED/SED separating shear zone. On the other hand, trend analysis was applied on the subsurface and surface data, reflecting a positive matching between the resulting trends from the magnetic and remote sensing data. The NW direction represents both data's major trend and less common NNW NS, NNE, and ENE trends. This relation reflects the extension and effect of the subsurface structures on the surface in the study area.

Keywords

• Remote sensing
• Aeromagnetic data
• Upward continuation
• Horizontal gradient magnitude
• Tilt derivative angle
• Shear zone