New Insights into the Tectonic Windows of the Eastern Desert of Egypt: An Integrated Field and Remote Sensing Approach

Abstract

This work is an integrated field and ASTER remote sensing approach for remapping and interpreting tectonic windows of the Eastern Desert of Egypt. These tectonic windows include the Hafafit, Sibai, Shalul, Meatiq and Beitan gneissic domes. The L1B data of the five areas are used, taking into consideration to avoid ASTER scenes after April, 2008 at which ASTER SWIR data show saturation of values and severe striping. False color composites (FCC) of the non-correlated bands 7, 3, 1 in RGB of the studied areas revealed a good match with field relations and observations. The relative good spatial and spectral resolution of ASTER imagery played an important role in distinguishing subtle spectral differences between the rock units outcropping in the studied areas. Field relations and observations collected from, at least three, cross-strike traverses in each dome, together with results obtained from microstructural investigations of the oriented samples and ASTER image processing led to accurate mapping of these domal structures. The results indicate that these structures of the Eastern Desert of Egypt are formed in a variety of tectonic settings, rather than in one setting, varying from (1) fold interference pattern involving multiply deformed sheath folds (Hafa-fit), (2) metamorphic core complex development due to regional extension (Meatiq and Sibai), (3) interference folding by single progressive deformation episode (Shalul) to (4) interference folding by separate sequential deformation events (Beitan).