New insights into the thermo-tectonic development of the Suez rift within the framework of the northern Arabian–Nubian Shield

Abstract

The Gulf of Suez is a young continental rift, the flanks of which make up the Arabian–Nubian Shield basement complex that formed during the East African Orogeny. The impact and significance of the consecutive tectono-thermal activities on the Arabian–Nubian Shield and the rifting processes in the Gulf of Suez remain uncertain. Combining zircon and apatite fission-track dating with time–temperature modelling has been effective in addressing these issues. We here present thermochronological data for 20 basement samples collected from the Samra Mountain region at the northern tip of the Gulf of Suez's eastern flank. Zircon fission-track data revealed two age groups separated spatially and dating from ca. 652 ± 25 Ma and ca. 426 ± 31 Ma. In contrast, apatite fission-track data revealed three spatially separated age groups dating from ca. 473 ± 10 Ma, ca. 269 ± 29 Ma and ca. 101 ± 12 Ma. Reconstructed time–temperature historical records revealed four distinct rapid cooling pulses (i.e. Neoproterozoic, Devonian–Carboniferous, Cretaceous and Oligocene–Miocene) consistent with the tectonic history and regional geology. By integrating our findings with the regional tectonic and sedimentation histories, the relationship between cooling events and exhumation events could be inferred. These cooling pulses were activated in response to four events: (1) the Precambrian–Cambrian post-accretion erosional event, (2) the Devonian–Carboniferous Variscan tectonic event, (3) the Cretaceous Gondwana disintegration and (4) the Oligocene–Miocene Gulf of Suez rifting, respectively. In the studied region, no thermal overprint was seen in association with the rifting in the Gulf of Suez, suggesting that the region had been segmented into northern and southern segments. A southward thermal source, the Arabian margin plume, caused an increase in the rift flank elevation and heat flow in the southern Sinai.