The impact of the Syrian Arc Orogeny on the Early Paleogene rocks, western shoulder of the Gulf of Suez, Egypt

Abstract

Integrated biostratigraphical and sedimentological studies on the Early Paleogene rocks (Thebes Formation) at four localities along the western shoulder of the Gulf of Suez, have provided an opportunity to evaluate the stratigraphy and the geological evolution of the sedimentary basins. The carbonate succession of the Thebes Formation represents a general regressive trend, which rests conformably to unconformably on the shales and marls of the Dakhla and Esna formations. The vertical facies change records a transition from deep- to mid-shelf to shoal, to lagoon, into a peritidal zone forming southwest gently-dipping slope to basin transect. Based on the study of the planktonic foraminiferal fossils; four zones have been defined according to the important planktonic foraminiferal taxa: Morozovella aragonensis/Morozovella subbotinae, Acarinina pentacamerata, Acarinina cuneicamerata of Ypresian age and Globigerinatheka kugleri/M. aragonensis of Early Lutetian age. The stratigraphy of the studied rocks is punctuated by three regional syn-depositional tectonic phases. The ages of these phases, have been determined chrono-stratigraphically as: Danian/Early Ypresian, Middle–Late Ypresian and Early Lutetian. Globally, these phases are three pronounced tectonic episodes in the tectonic history of the Syrian Arc Orogeny. The results suggest that the sedimentation regime was mainly controlled by external as well as internal parameters, which formulated the sedimentary basins.