Kinematics of Late Cretaceous subduction initiation in the Neo-Tethys Ocean reconstructed from ophiolites of Turkey, Cyprus, and Syria

Formation of new subduction zones represents one of the cornerstones of plate tectonics, yet both the kinematics and geodynamics governing this process remain enigmatic. A major subduction initiation event occurred in the Late Cretaceous, within the Neo-Tethys Ocean between Gondwana and Eurasia. Supra-subduction zone ophiolites (i.e., emerged fragments of ancient oceanic lithosphere formed at supra-subduction spreading centers) were generated during this subduction event, and are today distributed in the eastern Mediterranean region along three ~E-W trending ophiolitic belts. Several models have been proposed to explain the formation of these ophiolites and the evolution of the associated intra-Neo-Tethyan subduction zone.
Here we present new paleospreading directions from six Upper Cretaceous ophiolites of Turkey, Cyprus, and Syria, calculated using new and published paleomagnetic data from sheeted dyke complexes. Our results show that ~NNE-SSW subduction zones were formed within the Neo-Tethys during Late Cretaceous, which we propose were part of a major step-shaped subduction system composed of ~NNE-SSW and ~WNW-ESE segments. We infer that this subduction system developed within old lithosphere, along fracture zones and perpendicular weakness zones, since any Neo-Tethyan spreading ridge formed upon Triassic-Jurassic Gondwana fragmentation would have subducted to the north at the Pontides subduction zone by the Late Cretaceous.
Our new results provide and alternative kinematic model of Cretaceous Neo-Tethyan subduction initiation, and calls for future research on the mechanisms of subduction inception within old (and cold) lithosphere, and the formation of metamorphic soles below supra-subduction zone ophiolites in the absence of active spreading ridges.