Facies-based model and basin architecture of the Eocene succession in Egypt (Eastern Desert and Sinai): an example for tectonically controlled sedimentation on the southern Tethyan margin

Abstract

Integration of stratigraphy, spatial evolution, and syn-tectonism paved the way to propose a new depositional model for the Eocene rocks in the Eastern Desert and Sinai. Minia, Darat, Samalut, and Maghagha geological formations have been recognized. Eight sedimentary facies including tidal flat/lagoon complex, restricted inner lagoon, shoals, outer lagoon, back-bank, nummulite bank, fore-bank, and open marine have been identified. They were deposited in the shallow marine photic environment on a gently dipping platform ramp due to north of Egypt. Furthermore, this ramp shows three main faunal associations depending on water depth. The facies zones are arranged into a series of parallel NE-SW elongated subsiding sub-basins, separated by emerged and submerged swells rising from the bottom of the Eocene sea. Physically controlled sedimentary structures indicate a para-autochthonous to bio-concentration of the nummulite bodies. The spatio-temporal variations in the depositional environments and hiatuses in between and within the studied rock units indicate stratigraphic unrest. The Syrian Arc tectonism is the main trigger for such disturbance, which was rejuvenated and enlarged during the Late Cretaceous up to the Neogene in the eastern and southeastern Mediterranean domain.