New insights on the stratigraphy of the Upper Cretaceous-lower Paleogene successions at Esh-ElMellaha half-graben, Gulf of Suez, Egypt

Abstract

Detailed field and stratigraphic (lithostratigraphy & biostratigraphy) studies were carried out on the Upper Cretaceous–lower Paleogene successions at Esh-ElMellaha half-graben, Gulf of Suez, Egypt. Four stratigraphic sections were investigated and arranged in a geologic profile extends from south to north as follow: Gabal El-Mellaha, Wadi Abu Had, Wadi Dib and Gabal Tarbul. The field work led to recognize four lithostratigraphic units (formations): Sudr (upper part), Dib, Esna and Thebes (top). The distinctive Dababiya Quarry Member (DQM) which characterizes the Paleocene Eocene Thermal Maximum (PETM) was initially recorded at Esh-ElMellaha region. Sudr Formation is stratigraphically differentiated into two distinctive informal rock units, argillaceous bedded limestone unit and calcareous shale unit. The Dib Formation is here reviewed and correlates with the Dakhla Formation (upper part) in the different geographic neighborhoods of Egypt. It consists of glauconitic carbonate rocks (bioclastic limestone) embracing reworked gravelly and pebbly extra-clasts and broken exhumed mega-fossils (e.g. cephalopods, gastropods and bivalves, corals). Dib Formation is assigned to thelower Paleocene (Danian Stage) according to the occurrence of praemuricids taxa (e.g. Praemurica inconstans and P. uncinata) index fossils. Esna and Thebes formations are assigned to the Ypresian Stage. Dib Formation is bounded by two regional unconformity surfaces (erosional surfaces) as a result of two tectonic events (I and II) linked to Syrian Tectonic Event.