Genesis and geometry of tilted blocks in the Theban Hills, near Luxor (Upper Egypt)

Abstract

The desertic Theban hills between the edge of the alluvial plain of the Nile and the prominent cliffs at the eastern edge of the Theban Plateau consist of imbricated tilted blocks organized in parallel groups representing successive generations of gravitational collapse structures (or slumps). The older (distal) generations correspond to low, rounded hills farther from the Theban cliffs. The youngest (proximal) generation forms higher hills with young relief. Reverse faults occur at the contact between proximal and distal tilted blocks whereas the proximal tilted blocks rest along listric faults on the substratum (Tarawan Chalk and Esna Shale Formations) and against the Theban cliffs. We hypothesize that the emplacements of the tilted blocks were related to major Pleistocene pluvial episodes, each marked by active flow of the Nile River and significant recess of the Theban cliffs. Tectonic thinning and intensive erosion of the Esna Shale Formation were determinant in shaping the Theban landscape.