Testing the Mesozoic plate configuration of the Eastern Mediterranean domain

At the transition between the Atlantic and the Tethys oceanic systems, the plate kinematic configuration of the East Mediterranean domain during the early Mesozoic is still poorly understood. Several factors like the Messinian salt, the different compressional events, the thick carbonate platforms and Cenozoic deltaic deposits combine to blur the imaging of Eastern Mediterranean rifted margins. This has led to distinct and often markedly contrasting interpretations of the timing of opening (ranging from Carboniferous to Cretaceous), structural evolution (divergent to transform segments) and kinematics (N-S to WNW-ESE extension).

To address this long-standing problem, we gathered disparate geological observations from the margins surrounding the Eastern Mediterranean Sea to integrate them in a global plate model. Distinct, end-member plate kinematic scenarios were tested, challenged and iterated by observations from the Eastern Mediterranean rifted margins.

The N-African and NW-Arabian margins of the Eastern Mediterranean Sea are relatively weakly reactivated by the different compressional events and were chosen as the starting point of our integrative tectonic study. Legacy plate models for the area mostly show N-S to NNE-SSW opening of the Eastern Mediterranean of pre-Jurassic age. We have integrated dense industrial seismic data, deep boreholes and dredge data, as well as enhanced satellite gravity images that strongly suggests WNW-ESE oriented lithospheric extension and sea floor spreading during the Late Triassic to Early Jurassic.

Our approach starts by the mapping of the main extensional and compressional structures, the different crustal domains and the pre-rift facies distribution. We investigate the potential conjugate margins now located and imbricated in the Dinarides, Hellenides and Taurides on the northern side of the East Mediterranean Sea by looking at the drowning ages of the Mesozoic carbonate platform and the related rift structures. We refine the full fit and initial spreading of the Atlantic Ocean using crustal thickness and features observed on both sides of the system to calibrate the motion of Eurasia and Africa, which determine the space available to develop the Eastern Mediterranean Sea. Initial tests on the evolution of the main tectonic plates highlight an insufficient eastward motion of Africa relative to Eurasia (Iberia) to accommodate the extension of Eastern Mediterranean during the Jurassic with a purely WNW-ESE direction of extension. Further hypotheses remain to be tested. However, for now, a scenario involving poly-phased and poly-directional motion of the conjugate continent “Greater Adria” during Jurassic is favoured to model the Eastern Mediterranean plate evolution in relation with the closure of the Neo-Tethys further north.