Extreme impact of the Late Cretaceous–Paleocene tectonic events on the evolution of the southern Tethyan margin: a case study from Eastern Desert, Egypt

Abstract

The well-distributed Late Cretaceous–early Paleogene rocks in Egypt are one of the keys to understanding the geologic history of the southern Tethys. Four Late Cretaceous–early Paleogene successions exposed in the Esh-ElMellaha area were investigated. The integrated stratigraphic analyses, including; field, lithostratigraphy and biostratigraphy of these sections within the Esh-ElMellaha ridge showed interesting results. Intensive tectonic processes throughout Paleocene period substantially influenced all rock units, causing differences in their facies and thickness. In addition, these tectonic processes deformed the sedimentary basins. During the Paleocene, Esh-ElMellaha area experienced two significant syn-sedimentary tectonic events (I and II) related to the Syrian Arc Tectonic Event. The evolution of the Esh-ElMellaha basin has been documented for the first time throughout this period which is extremely dependent upon these tectonic events. Four paleo-relief profiles were created to illustrate how these events impacted the history of sedimentary basins, extending from the North Wadi Qena northward to the Gabal Hamadat southward. The strength of tectonic events caused the Esh-ElMellaha area to undergo substantially varied degrees of instability. These profiles demonstrate the stability of the deposition during the Maastrichtian period. However, during the Danian, the basin experienced the deposition of thin strata expanding from north to south. This uplifted the basin into submarine paleohigh and created an erosional surface. During the late Paleocene (Selandian-Thanetian), the basin was deeper in the south (Hamadat) than in the north (North Wadi Qena). In contrast, the basin in the Esh-ElMellaha area became an aerial paleohigh, an event that began at the end of the Danian and continued until the early Eocene (Ypresian). This uplift led to the formation of significant paleosol layers. Moreover, the depocenter's southern sections of Esh-ElMellaha had a less tectonic effect, while the northern regions of Esh-ElMellaha witnessed extreme tectonic activity.