Architecture and metamorphic imprint of an orogenic wedge and its development during ophiolite obduction: insights from the Jabal Akhdar Dome, Oman

This thesis presents and discusses the regional-scale structural framework and metamorphic imprint of the Jabal Akhdar tectonic window, in the Oman Mountains. Numerous studies have tried to constrain the geologic history of the northeastern margin of the Arabian Plate, especially regarding the Late Cretaceous subduction and obduction process that affected it during its convergence towards Eurasia, but the overprinting of multiple geodynamic events over more than 600 Myrs has led, at times, to ambiguity. Following a field campaign in Jabal Akhdar aimed at the structural characterization of various key areas of Jabal Akhdar and the detailed collection of a substantial amount of mesostructural data, metamorphic analyses were conducted on representative and structurally-constrained samples. Specifically, Raman Spectroscopy on Carbonaceous Material (RSCM) enabled the extrapolation of the maximum temperature recorded by microscopic graphite flakes within highly deformed samples, while Electron Microprobe spot analyses (EPMA) allowed for the estimate of metamorphic pressure and temperature conditions using the multi-equilibrium chlorite-phengite-quartz-water approach. The result is a new, comprehensive tectonic model spanning the Late Cretaceous and reconciling the collected structural data with the estimated metamorphic imprint.